University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Environmental

Classification: Environmental

Citations 186

"A Sensitive Colorimetric Method For The Determination Of Arsenic In Environmental And Biological Samples"
J. Chin. Chem. Soc. 1999 Volume 46, Issue 4 Pages 641-645
Omi Agrawal, G. Sunita and V. K. Gupta

Abstract: Results of a thorough study and application of leucocrystal violet for the determination of arsenic in parts per million (ppm) levels in environmental and biological samples is described here. The proposed method is based on the reaction of arsenic with potassium iodate to liberate iodine. The liberated iodine selectively oxidises leucocrystal violet to form crystal violet dye in the presence of sodium hydroxide. The dye formed shows maximum absorbance at 592 nm. The detection limit of arsenic is 0.002 µg mL-1 and the method obeys Beers law over the concentration range of 0.1 µg - 1.0 µg of per 25 mL of final solution (0.004 - 0.04 ppm). The molar absorptivity was found to be 1.49 x 10(6) L mol-1 cm-1. The proposed method was successfully applied for the determination of arsenic in various environmental and biological samples. The results are in good agreement with the standard reported method.
Spectrophotometry Standard method

"Monitoring Of Environmental Parameters By Sequential Injection Analysis"
Trends Anal. Chem. 2001 Volume 20, Issue 8 Pages 407-418
V. Cerdà, A. Cerdà, A. Cladera, M. T. Oms, F. Mas, E. Gómez, F. Bauzá, M. Miró, R. Forteza and J. M. Estela

Abstract: The use of sequential injection analysis (SIA), as applied to the control of environmental parameters, is reviewed. Its advantages and drawbacks are compared with those of flow injection analysis (FIA). FIA is simpler and easier to handle, has a higher sample throughput, and may be controlled manually, but SIA is more robust and versatile and better adapted for multiparametric and stopped flow techniques. (C) 2001 Elsevier Science B.V. All rights reserved.
Preconcentration Extraction Sequential injection Review

"A New System For The Spectrophotometric Determination Of Arsenic In Environmental And Biological Samples"
Anal. Chim. Acta 2000 Volume 408, Issue 1-2 Pages 111-115
Ajai Pillai, G. Sunita and V. K. Gupta

Abstract: A new sensitive method is proposed for the determination of traces of arsenic(III). The method involves bleaching of the pinkish red colored dye, Rhodamine-B, by the action of iodine which is released by the reaction between potassium iodate and arsenic in slightly acidic medium. The color of the dye was measured at 553 nm. Beers law is obeyed in the concentration range of 0.04-0.4 mg L-1 of arsenic. The molar absorptivity was found to be 3.24 x 10(5) l mol-1 cm-1. The proposed method has been successfully applied for the determination of arsenic in various environmental and biological samples.
Arsenic(3+) Spectrophotometry Indirect

"The Proper Place Of Analytical Chemistry In Environmental Management"
Crit. Rev. Anal. Chem. 1999 Volume 29, Issue 2 Pages 155-162
Jirí Janata

Abstract: Obtaining new information through characterizaton (chemical analysis) has its costs associated with it. These costs must be justified. It is argued that the value of any analysis, new chemical sensor, or a new analytical procedure for environmental management task is ultimately determined by its rational use. A formal procedure for justification of chemical characterization is outlined.

"Analytical Pervaporation: An Advantageous Alternative To Headspace And Purge-and-trap Techniques"
Chromatographia 2000 Volume 52, Issue 5-6 Pages 265-272
M. D. Luque de Castro and L. Gámiz-Gracia

Abstract: An overview of the principles and general applications of analytical pervaporation is presented. The different designs of both the analytical pervaporation module and the continuous manifolds to which the pervaporator is connected are discussed. The versatility of this non-chromatographic continuous separation technique for circumventing some of the shortcomings encountered in the automation of the overall analytical process is shown. Examples of methods developed for samples (both liquid and solid) in the environmental, food and beverage, and clinical and pharmaceutical fields are shown. The potential of pervaporation as an alternative to static and dynamic well-established approaches such as headspace and purge-and-trap sampling prior to gas-chromatographic separation is demonstrated. Examples of this approach involving both solid and liquid samples are discussed.
Spectrophotometry Review Pervaporation

"Functionalized Cellulose Sorbents For Preconcentration Of Trace Metals In Environmental Analysis"
Crit. Rev. Anal. Chem. 1999 Volume 29, Issue 4 Pages 313-321
Krystyna Pyrzyñska and Marek Trojanowicz

Abstract: Regardless the progress in detectability of various instrumentation for trace metal determination, the pre-concentration steps are very often needed for the analysis of environmental samples. Among the different techniques that can be used for this purpose, solid-phase extraction using various sorbents has been developed very intensively in recent years. Besides pre-concentration, it can also be used for matrix removal necessary in some procedures or for the speciation of trace elements. This review is based on 42 literature references and shows favorable properties of cellulose sorbents for this purpose. Depending on the functional groups attached, the sorbent can be directly used for sorption of target analytes or can be loaded with ligands specifically binding certain species. Applications are reviewed for conventional batch procedures, flow injection sample processing, and speciation of certain trace elements.
Metals, trace Spectrophotometry Mass spectrometry Spectrophotometry Preconcentration Cellex Review

"Electrochemical Sensor Arrays"
Crit. Rev. Anal. Chem. 1999 Volume 29, Issue 2 Pages 133-153
Raluca-Ioana Stefan, Jacobus F. Van Staden and Hassan Y. Aboul-Enein

Abstract: The importance of sensor arrays in environmental, food and clinical analysis is discussed. The possible designs of sensor arrays is shown. The most reliable mathematical models for data processing are presented. The importance of different types of electrochemical sensor arrays in analytical chemistry as well as their performances are shown.
Sensor Electrochemical analysis Chemometrics Non-immobilized enzyme Review

"Repetitive Determinations Of Iron(III) In Closed Flow-through Systems By Series Reactions"
Anal. Chim. Acta 1977 Volume 94, Issue 2 Pages 289-296
V. V. S. Eswara Dutt, Daniel Scheeler and Horacio A. Mottola

Abstract: The determination of iron(III) with thiocyanate by means of sample injection into a chamber in a closed loop system of circulating reagent is described. Restitution of the absorbance to baseline by ligand exchange and by a redox process in the presence of iodide is discussed, together with some kinetic aspects of the decolorization reaction responsible for the return to the baseline. The iron content of the samples is deduced from the height of the generated transient signal, which is directly proportional to the iron(III) content. As many as 350 determinations/h can be processed when ligand exchange is used and 120/h when iodide is used for baseline restitution. Sample injection techniques of this type are particularly useful in industrial processes and quality control, and environmental monitoring, since they result in a decrease in operating cost and time.
Iron(III) Spectrophotometry Closed loop Redox Kinetic

"Combination Of Flow Injection Techniques With Atomic Spectrometry In Agricultural And Environmental Analysis"
Anal. Chim. Acta 1986 Volume 179, Issue 1 Pages 325-340
Zhaolun Fang, Shukun Xu, Xiu Wang and Suchun Zhang

Abstract: A review is presented, with 37 references, in which the applications of the coupled techniques are discussed with emphasis on agricultural and environmental analyzes.
Arsenic Cadmium Selenium Ion exchange Spectrophotometry Spectrophotometry Spectrophotometry Spectrophotometry Spectrophotometry Review Preconcentration Standard additions calibration

"Liquid Chromatographic Method With Fluorescence Detection For The Determination Of Polycyclic Aromatic Hydrocarbons In Environmental Samples"
Anal. Chim. Acta 1990 Volume 234, Issue 1 Pages 269-273
M. D. Núñez and F. Centrich

Abstract: A method for the determination of some polynuclear aromatic hydrocarbons (PAHs) in water samples and air filters is presented. Samples were extracted with light petroleum-diethyl ether (85 + 15) and the extracts were concentrated before analysis. Reversed-phase liquid chromatography with fluorescence detection was applied to separate and determine the PAHs. Recoveries of individual PAHs from spiked water samples were 0.16-0.27 ng mL-1. Detection limits in the picogram range were obtained for each compound.
Hydrocarbons, aromatic, polycyclic LC Fluorescence Sample preparation Filter Extraction Post-column derivatization

"Determination Of A Non-ionic Surfactant In Aqueous Environmental Samples By Flow Injection Analysis With Chemiluminescence Detection"
Anal. Chim. Acta 1990 Volume 239, Issue 2 Pages 189-194
J. Steven Lancaster and Paul J. Worsfold, A. Lynes

Abstract: Nonidet AT 85 was determined in seawater, with use of a glass coil flow cell; sample (100 µL) was merged first with borate buffer, pH 10.5, then with 4.45 mM rhodamine B and finally with 0.46 M NaOCl. The luminescence was measured with a photomultiplier. The response was rectilinear up to 50 mg L-1 with a limit of detection of 5 mg L-1 and coefficient of variation (n = 6) from 2.9% to 26.8% for these limits, respectively.
Surfactants, non ionic Chemiluminescence Glass Flowcell Buffer pH Detection limit

"Solid-state Microprocessor-controlled Detector For Doublet Peak Measurements In Flow Injection Analysis"
Anal. Chim. Acta 1994 Volume 295, Issue 1-2 Pages 143-149
Mary K. Carroll, Michael Conboy, Asaph Murfin and Julian F. Tyson*

Abstract: In FIA a doublet peak occurs if the analyte concentration is too high when the centre of the sample plug reaches the detector. The time difference between the two peaks is proportional to ln concentration and use of the doublet can extend the working range. A detector is described using this principle. Sample solutions are injected into a tightly coiled mixing coil (60 cm x 0.9 mm i.d.) carrying the reagent and the solution passes through the detector unit with red, yellow and green ultrabright light-emitting diodes and emission centred at 630, 585 and 565 nm and mounted perpendicular to the flow direction. Opposite each is a photodiode detector. The flow cell is a square-section capillary (5 cm x 1 mm x 1 mm) with a sampled volume at each light source-detector pair of 1 µL. The whole unit is controlled by a microprocessor. The use was exemplified with a carrier stream (1.32 ml/min) of 10 µM-HCl containing 6 µM-bromothymol blue, injection of 0.011-110 mM NaOH and use of the red light source. The photodiode output was sent to a plotter, an oscilloscope or a computer. The calibration graph was linear over the whole range. Facilities also exist for several flow lines and for laser transmission or fluorescence measurements.
Indium Spectrophotometry Light emitting diode Photodiode

"Flow Injection Analysis Of Phenols At A Graphite Electrode Modified With Co-immobilized Laccase And Tyrosinase"
Anal. Chim. Acta 1995 Volume 308, Issue 1-3 Pages 137-144
A. I. Yaropolov*, A. N. Kharybin, J. Emnéus, G. Marko-Varga and L. Gorton

Abstract: An amperometric biosensor for the detection of phenols was prepared by co-immobilizing laccase and tyrosinase onto a spectrographic graphite electrode. The biosensor was mounted in a three-electrode flow-through detector cell equipped with a Ag/AgCl (0.1 M KCl) reference electrode and a Pt-wire auxiliary electrode. The detector cell was used in a FIA system for the detection of a large group of phenolic compounds. A carrier electrolyte of 0.1 M citrate buffer of pH 5 was used at 0.55 ml/min and the biosensor was maintained at -0.05V vs. Ag/AgCl. The injection volume was 50 µL. The relative activity of the biosensor towards different phenolic compounds was investigated.
Phenols Sensor Amperometry Electrode Electrode

"Flow Injection Sorbent Extraction With Dialkyldithiophosphates As Chelating Agent For The Determination Of Zinc By Flame Atomic Absorption Spectrometry"
Anal. Chim. Acta 1995 Volume 309, Issue 1-3 Pages 395-403
Renli Ma, Willy Van Mol and Freddy Adams*

Abstract: Biological and environmental samples (100 mg) were digested as previously described (Ibid., 1994, 293, 251) and diluted to 50 mL with water. Portions were injected over 20 s at 8.7 ml/min into a carrier stream (~2 ml/min) of 0.5% di-sec-butyldiothiophosphate in 100 mM citrate buffer of pH 3 and the Zn chelate retained on a reverse-phase column (Ibid., 1994, 285, 33). The chelate was eluted with methanol and Zn determined by AAS using a spray chamber flow spoiler. Calibration graphs were linear up to 50 µg/l of Zn with RSD (n = 5) of better than 3% and a detection limit of 0.5 µg/l. The presence of 100 mg/l of Fe and Ni interfered. Fe did not however interfere when present at 10 mg/l.
Zinc Spectrophotometry Sample preparation Chelation Matrix removal Interferences Solid phase extraction

"Direct Determination Of Ultratraces Of Thallium In Water By Flow Injection Differential Pulse Anodic-stripping Voltammetry"
Anal. Chim. Acta 1996 Volume 318, Issue 2 Pages 159-165
Zenon Lukaszewski*, Wlodzimierz Zembrzuski and Anna Piela

Abstract: Filtered water samples were diluted with 0.2 M ETDA (3:1) and 100 mL of the solution was continuously circulated at a flow rate of 15 ml/min through a voltammetric cell during the deposition period. The voltammetric cell was equipped with a Hg film working electrode on an epoxy resin impregnated graphite substrate (3.14 mm2), a SCE as the reference electrode and a Pt wire auxiliary electrode. The deposition was carried out at -900 mV for up to 120 min. At the end of the deposition period the flow was stopped and after 30 s the voltammogram was recorded by scanning the potential to ~e;-300 mV at 11.1 mV/s with a pulse amplitude of 50 mV. The calibration graph was linear from 25-100 pM-Tl with a 90 min deposition period and the detection limit was 10 pM. The RSD (n = 6-8) was 0.14% within the calibration range. The method was tolerant of a 1000-fold excess of Pb. The method was applied to the analysis of tap, river, lake and sea waters.
Thallium Voltammetry Ultratrace Interferences

"Gas Diffusion Techniques Coupled Sequential Injection Analysis For Selective Determination Of Ammonium"
Anal. Chim. Acta 1996 Volume 318, Issue 3 Pages 251-260
M. T. Oms, A. Cerdà, A. Cladera, V. Cerdà* and R. Forteza

Abstract: A computer-controlled sequential injection analysis system for the determination of ammonium ions in water is described. A 75 µL sample and 100 µL 0.01 M NaOH were sequentially aspirated and mixed by flow reversal while being propelled (2 ml/min) to a gas diffusion unit. Ammonia diffused through a Durapore hydrophobic membrane (0.22-0.45 µm pore size, 125 µm thick) and was collected in 1 mL 80 µM-bromothymol blue (BTB) at pH 6. The BTB was propelled to a spectrophotometer and the absorbance was measured at 620 nm. The calibration graph for ammonium ions was linear for up to 60 mg/l and the RSD (n = 10) at 30 mg/l was 2.5%. The detection limits were 2 and 0.5 mg/l for one and five flow reversals, respectively. No interference from a 20-fold excess of Cu(II), Fe(III) and Zn, a 40-fold excess of carbonate or sulfite, Ca and Mg or a 100-fold excess of chloride, nitrate or sulfate was observed. The method was applied to the analysis of filtered waste water and aqueous extracts of atmospheric aerosols. The results were confirmed by a FIA method based on the formation of indophenol blue.
Ammonium Spectrophotometry Sequential injection Interferences Gas diffusion Hydrophobic membrane

"Model Compounds For The Determination Of Organic And Total Phosphorus Dissolved In Natural Waters"
Anal. Chim. Acta 1996 Volume 318, Issue 3 Pages 385-390
Roger Kérouel and Alain Aminot*

Abstract: Methods for the determination of organic and total P in natural waters based on the hydrolysis and oxidation of all complexed forms of P to phosphate by acidic and alkaline persulfate oxidation, continuous-flow UV irradiation and high temperature combustion (HTC) were studied. Ten compounds were used to test the efficiency of these hydrolysis/oxidation reactions. The results indicated that in such methods, recoveries should be tested using model compounds with HTC as the reference method. One labile compound (phosphoenolpyruvate, glycerophosphate or riboflavin-5-phosphate) and one refractory compound (aminoethylphosphonic acid, phytic acid or phosphorylcholine) should be used to determine an upper and lower recovery, respectively. The recoveries depended on the matrix; quantitative recoveries were obtained with fresh water but not with seawater. For the determination of P in seawater the alkaline persulfate oxidation method is recommended.
Phosphorus

"Novel Potentiometric Monitoring Combined With Coulometric Reagent Generation"
Anal. Chim. Acta 1996 Volume 319, Issue 1-2 Pages 49-58
Géza Nagy, Klára Tóth*, Zsófia Fehér and Jen Kunovits

Abstract: A potentiometric flow-through monitor was developed in which different amounts of standard or reagent were added to the sample stream by current-programmed coulometry. The monitor was utilized to monitor the concentration of chloride in tap water over an 8 h period. The tap water stream (5.51 x 10^-5 L/s) was merged with a Ag+ ion reagent stream (5.51 x 10^-5 L/s) in 0.1 M KNO3/5 mM HNO3 produced coulometrically at 3.5 mA (~e;30 mV) at a Ag electrode with a Pt wire counter electrode. The flow then passed through the potentiometric detection cell which was equipped with a chloride ISE as the indicator electrode and a double junction calomel reference electrode. A computer was used for data acquisition, for electrical noise rejection, for signal recognition and for calculating the analytical results. Over an 8 h period the concentration of chloride in tap water was found to fluctuate between 0.45-0.70 mmol/L using a measurement cycle of 400 s.
Chloride Potentiometry Electrode

"Online Multicomponent Determination Of Organic Compounds In Water Following Gel-permeation Chromatographic Separation"
Anal. Chim. Acta 1996 Volume 319, Issue 1-2 Pages 165-175
Jolanta Oleksy-Frenzel* and Martin Jekel

Abstract: A system coupling GPC with air-segmented flow analyzer.s for dissolved organic carbon (DOC), nitrogen (DON) and halogens (DOX) was described for the characterization of water samples. The chromatography was carried out on a Fractogel TSK 40 HW column (70 cm x 16 mm i.d.) with a sample injection volume of 1 ml, phosphate buffer at pH 7 as the mobile phase (0.8 ml/min) and UV-visible diode array detection (190-800 nm). The column effluent was divided into two streams. One steam passed to the DOC analyzer. and the other to the DON analyzer. and then to the DOX analyzer.. The DOC analyzer. was based on the H2SO4 oxidation of organic carbons to CO2 which was collected via a gas diffusion unit and detected photometrically with a pH indicator. The DON analyzer. was based on the oxidation of organic nitrogen to nitrate by UV digestion in the presence of peroxodisulfate for spectrophotometric detection. The DOX analyzer. was based on the potentiometric detection of halides at a Ag/AgCl electrode. The system was tested with various organic compounds and quantitative recoveries were obtained. The system was applied to the characterization of filtered waste water from chemical processing.
Organic compounds GPC Potentiometry Spectrophotometry Sample preparation Gas diffusion UV reactor Photochemistry

"Determination Of Calcium In Water, Urine And Pharmaceutical Samples By Sequential Injection Analysis"
Anal. Chim. Acta 1996 Volume 323, Issue 1-3 Pages 75-85
J. F. van Staden* and R. E. Taljaard

Abstract: The sequential injection analysis is based on the fast complexation reaction between metalphthalein and Ca2+ followed by spectrophotometric detection at 573 nm. Plugs of 0.31 mL of water, 0.47 mL of 14% 2-amino-2-methylpropanol-1-ol buffer solution of pH 10.5, 0.23 mL of 0.0025% metalphthalein solution of pH 1.9 and 0.23 mL of sample were drawn at 4.68 ml/min into a holding coil (50 cm x 1.6 mm i.d.). The flow was then reversed and the stacked plugs were propelled through reaction coils (90 cm x 1.1 mm i.d. and 115 cm x 0.6 mm i.d.) to the flow-though detection cell (80 µL) where the absorbance was measured. A linear response was obtained for up to 20 mg/l of Ca and the detection limit was 0.05 mg/l. The RSD (n = 10) for 1-20 mg/l Ca were 0.66-0.85%. The method was applied to the determination of Ca in an effervescent tablet, tap water and urine, and the results were validated by AAS. The sampling frequency was 43 per h.
Calcium Spectrophotometry Sequential injection

"Determination Of Gaseous Carbon Dioxide By Enhancement Of Luminol-cobalt(II) Phthalocyanine Chemiluminescence: Analysis Of Atmospheric Air And Human Breath"
Anal. Chim. Acta 1996 Volume 329, Issue 3 Pages 305-310
Zhang-Hua Lan and Horacio A. Mottola*

Abstract: Atmospheric air at a minminium of 35 ml/min was pumped into a continuous-flow (1.2 ml/min) solution of 5 mM luminol/cobalt(II) phthalocyanine of pH 12.6 and the solutions mixed in a windowed black PTFE reaction cell. Log-log calibration graphs of the CO2 enhanced led light vs. CO2 were linear up to 800 ppm of CO2 with a detection limit of 1.5 ppm CO2. At 320 ppm CO2 a RSD (n = 11) of 1.2% was obtained with quantitative recoveries in the range 200-600 ppm of CO2. Using a modified apparatus, 100 µL human breath was injected into a continuous-flow (5.2 ml/min) of the 5 mM luminol/cobalt(II) phthalocyanine reagent and CO2 was detected as before. Using the modified apparatus, a response time to CO2 of 1 s and a recovery time of 2.6 s was observed. Sulfur dioxide, nitrogen oxides and ozone were adjusted to cause non-significant interference.
Carbon dioxide Chemiluminescence Interferences

"Determination Of Copper In Natural Waters By Batch And Oscillating Flow Injection Stripping Potentiometry"
Anal. Chim. Acta 1996 Volume 330, Issue 1 Pages 79-87
Christopher W. K. Chow, Spas D. Kolev, David E. Davey*, and Dennis E. Mulcahy

Abstract: Batch potentiometric stripping analysis (PSA) and oscillating flow injection stripping potentiometry (OFISP) were compared for determining Cu in water rich in chloride ions and organic matter. PSA was performed at a glassy carbon electrode coated with a Hg film deposited from 30 mg/l mercury nitrate in 0.1 M HCl at -900 mV vs. Ag/AgCl (3 M KCl). The deposition of Cu was carried out at the same potential for 1 min from 50 mL water acidified to 0.1 M HCl or 0.1 M HNO3 and containing 10 mg/l mercury nitrate. The remaining experimental details were given by Chow et al. (Anal. Chim. Acta, 1995, 307, 15). OFISP was performed using the same PSA apparatus incorporated into a FIA system. A carrier stream of 0.1 M HNO3 or 0.1 M HCl was used with a 100 µL injection loop. The experimental details were given by Kolev et al. (Ibid., 1995, 309, 293. For both PSA and OFISP external and standard addition calibration procedures were employed. The two analytical technique gave the same results when HCl media were used. The flow injection OFISP method was recommended for analyzing natural waters because it showed a low sensitivity to matrix effects. The analysis of natural waters by adsorption stripping voltammetry was unsatisfactory due to the adsorption of the organic matter onto the working electrode.
Copper Potentiometric stripping analysis Potentiometry

"Highly Sensitive Spectrophotometric Determination Of Nitrite Ion Using 5,10,15,20-tetrakis(4-aminophenyl)porphine For Application To Natural Waters"
Anal. Chim. Acta 1996 Volume 333, Issue 1-2 Pages 175-180
T. Kawakami and S. Igarashi*

Abstract: To 1 mL 0.05 mM 5,10,15,20-tetrakis(4-aminophenyl)porphine aqueous solution was added 1 mL 1 M HCl to give a final pH of 1 and a portion of standard nitrite (I) solution, and the mixture was diluted to 10 mL. After 30 min at 30°C, the change in absorbance due to diazotization was measured at 434 nm. The calibration graph was linear up to 0.4 µM-I (up to 18 ng/ml) with a detection limit of 4 nM (0.18 ng/ml). The RSD (n = 10) was 1% for 0.2 µM-I. Many foreign ions were tolerated in large amounts. The method was applied to the determination of nitrite in rain, spring and tap water. Interference by Fe(III) was masked by adding 1 mL 1 mM EDTA to the initial mixture. The results agreed with those obtained by ion chromatography and a FIA method.
Nitrite Spectrophotometry Interferences

"Determination Of Trimethylamine Oxide In Seawater And Small Volumes Of Seafood Tissue Extract Using Flow Injection Analysis"
Anal. Chim. Acta 1996 Volume 334, Issue 3 Pages 279-285
Saloua Sadok, Roger F. Uglow and Stephen J. Haswell*

Abstract: The supernatant of homogenized and centrifuged seafood (1 ml) was treated with 20 µL of 15% TiCl3 solution to reduce trimethylamine oxide to trimethylamine, and a 100 µL portion was injected directly into a FIA system in which it was mixed with 12% formaldehyde solution followed by 0.6 M NaOH and 0.03% bromothymol blue solution (all at 1 ml/min) and passed through a gas-permeable membrane, with detection at 635 nm. A second sample portion was analyzed without reduction to determine the original trimethylamine, and the difference in peak heights gave the amount of oxide present. Seawater was also analyzed with use of a 300 µL volume loop and 0.35 M NaOH. Linear calibration graphs for six standards in 6% HClO4 were obtained in the range 10^-200 µM, with RSD (n = 10) of ?. The detection limit was 6 µM-trimethylamine oxide. The corresponding values in seawater were 10^-100 µM and 2.5 µM.
Trimethylamine oxide Spectrophotometry Sample preparation

"Enhancing The Performance Of Membrane Introduction Mass Spectrometry By Organic Carrier And Liquid Chromatographic Separation"
Anal. Chim. Acta 1997 Volume 337, Issue 2 Pages 165-172
Shi Ouyang, Yong Hong Chen* and Yan Xu*

Abstract: A method of membrane introduction mass spectrometry with liquid chromatographic separation (LC/MIMS) for the analysis of volatile organic compounds (VOCs) in water has been developed. The method not only inherited all the advantages of membrane introduction mass spectrometry by flow injection analysis (FIA/MIMS), but also expanded the application of MIMS to the determination of compounds with identical quantitation ions. Because the quantitation by LC/MIMS is based on two-dimensional identification (retention time (t-r) and mass-to-charge ratio (m/z)), it provides a tangible approach to the analysis of VOCs in complex aqueous samples. In this work, a C-18 column and a mobile phase (methanol/water) were used for chromatographic separation. A mixture of eighteen VOCs was determined within 28 min. The method has linear dynamic ranges of 3-4 orders of magnitude and sub-ppb-level detection limits. In comparison with the EPA method 524.2 (a purge-and-trap GC/MS method), it requires less analysis time and no sample pretreatment.
Organics, volatile Mass spectrometry Interface Method comparison

"Flow Injection Analysis Of Traces Of Lead And Cadmium By Solvent Extraction By Dithizone"
Talanta 1980 Volume 27, Issue 2 Pages 169-175
O. Klinghoffer, J. Rika and E. H. Hansen

Abstract: An automated solvent extraction method for determination Pb and Cd down to the 50 ng/ml level has been developed. Optimum conditions for selective and sensitive determination were designed and verified by using the flow injection scanning method. Application to pollution control is discussed.
Lead Cadmium Spectrophotometry Sample preparation Solvent extraction Optimization PPB Dithizone

"Background Current Subtraction In Voltammetric Detection For Flow Injection Analysis"
Talanta 1984 Volume 31, Issue 5 Pages 387-390
Joseph Wang* and Howard D. Dewald

Abstract: Compensation for background currents due to evolution of H, reduction of O, solvent oxidation or surface processes was made by recording the voltammogram while the sample and carrier solution flowed through the cell and taking the difference as the net response for the sample. The electrochemical detector was that described previously (Anal. Chim. Acta, 1983, 153, 325). Various 3-mm diameter disc working electrodes were used, including mercury-coated vitreous carbon (for measurements in the cathodic region), bare vitreous carbon and carbon paste. A silver - AgCl reference electrode and a carbon-rod auxiliary electrode were used. All measurements were made with a Sargent-Welch model 4001 polarograph. At a flow rate of 0.3 mL min-1, ~15 samples per h could be analyzed. The coefficient of variation for 25 µM-Pb was 0.4% (n = 7); other test analytes included Bi, phenol, chlorpromazine and noradrenaline.
Acetaminophen Bismuth Cadmium Chlorpromazine Lead Norepinephrine Phenols Zinc Electrode Electrode Electrode Voltammetry

"Speciation Studies By Flow Injection Analysis"
Talanta 1986 Volume 33, Issue 1 Pages 45-50
M. D. Luque De Castro

Abstract: A review is presented of the cited technique in inorganic and environmental analysis. (53 references).
Review Speciation

"Apparatus For The Determination Of Volatile Analytes By Stopped-flow Injection Analysis Using An Integrated Fibre Optic Detector"
Talanta 1994 Volume 41, Issue 3 Pages 347-354
P. J. Baxter, J. Rika and G. D. Christian*D. C. Olson

Abstract: A stopped-flow injection analysis system for measuring volatile analytes originating from either liquid or gas phases was tested using NH3 as a model analyte. The system consisted of a detection/reaction sandwich cell containing a Celgard 2500 membrane (0.04 µm pore size, 25 µm thick) which allowed the NH3 to diffuse from the donor phase to the acceptor solution The diffusion path was 11.5 x 1.8 mm which resulted in a total acceptor volume of 17 µL. Light was delivered to the sandwich cell via a bifurcated optical fiber and the reflected light was measured as absorbance after passing through a 620 nm filter. Gaseous analytes were injected into an air donor stream and the acceptor solution (2.2 ml/min) was 0.1 mM bromothymol blue (pH 6.4). Liquid analytes were injected into 0.05 M borate buffer (pH 9.35) donor stream (1 ml/min) and the flow was stopped for 30 s when the analyte reached the sandwich cell. The acceptor stream (1 ml/min) was 0.1 mM bromocresol green (pH 3.7). The calibration graphs were linear for 255-1000 ppb (gas phase analysis) and 1-100 ppm (aqueous phase analysis) and the detection limits were 40 ppb and 1 ppm, respectively.
Ammonia Spectrophotometry Stopped-flow Celgard

"Speciation Of Dissolved Phosphorus In Environmental Samples By Gel Filtration And Flow Injection Analysis"
Talanta 1993 Volume 40, Issue 12 Pages 1981-1993
I. D. McKelvie* and B. T. HartT. J. Cardwell and R. W. Cattrall,

Abstract: Water (0.6 ml) was chromatographed on columns (10 cm x 1 cm i.d.) of Fast Desalting Sephadex G25, with a mobile phase (1.2 ml/min) of Tris hydrochloride of pH 4.65 (I = 0.005M). Sediments were extracted with 25 mM borate buffer of pH 9.2, the extracts were filtered and diluted (1:9). Portions (0.35 ml) of these solution were chromatographed on columns (4.2 cm x 1 cm i.d.) of Sephadex G25 Superfine, with the same mobile phase (0.65 ml/min). These columns partially separated high-mol.-wt. P compounds (exemplified by phytic acid, I) from low-mol.-wt. P compounds (exemplified by phosphate, II). The column effluent was mixed with 148 mM potassium persulfate solution in 25 mM borax (1.2 ml/min) and P compounds were oxidized by exposure to UV radiation. Subsequent reagents, 8.1 mM ammonium molybdate in 0.63 M H2SO4 (1 ml/min) and 0.89 mM SnCl2 and 15 mM hydrazine sulfate in 0.5 M H2SO4 (0.7 ml/min) were mixed in separately and absorbances were measured at 690 nm. Calibration graphs were linear for 100-1000 and 10^-100 µg/l of P with detection limits for I and II for the lower range were 27 and 1.1 µg/l as P.
Phosphorus Spectrophotometry Sample preparation Speciation Filtration Extraction

"Selectivity Coefficients For Amperometric Sensors"
Talanta 1994 Volume 41, Issue 6 Pages 857-863
Joseph Wang,

Abstract: A generalized method is presented for assessing the extent of interference by foreign species in amperometric determination of an analyte. An expression is given for the limiting current of an amperometric device in response to an analyte in the presence of an interfering species. Experiments were carried out with a Pt electrode, modified with glucose oxidase by electropolymerization from 0.2 M acetate buffer of pH 5.2 containing o-phenylenediamine or coated with Nafion/glucose oxidase solution in phosphate buffer of pH 7.4, and with glucose oxidase incorporated into a C paste electrode containing Ru or 2-methyl-1,4-naphthoquinone. Pt electrodes, bare and coated with 2 or 5% Nafion, were also evaluated. The enzyme-free electrodes were used for monitoring dopamine with ascorbic acid, 3,4-dihydroxyphenylacetic acid and adrenaline by FIA and chronoamperometry; the Nafion-coated electrodes showed good selectivity relative to the first two compounds. The enzyme electrodes were used to monitor glucose in the presence of ascorbic acid, uric acid, paracetamol, catechol and dopamine by FIA. The Pt/Nafion/enzyme electrode showed the best selectivity. The validity of the theoretical approach was confirmed.
Glucose Dopamine Amperometry Electrode Electrode Electrode Sensor Interferences

"Investigations For The Determination Of Lead By In Situ Hydride Trapping Within A Graphite Electrothermal Atomizer For Routine Analysis"
Talanta 1995 Volume 42, Issue 7 Pages 927-936
D. Erber*, L. Quick, F. Winter and K. Cammann,

Abstract: A commercial system (Perkin-Elmer Model 4100 ZL atomic absorption spectrometer with a FIAS 200 hydride generator) for the flow injection AAS determination of Pb in environmental samples was evaluated. The hydride generation was optimized by using an ammonium peroxidisulfate-HCl system as oxidant and NaBH4 as reducing agent. The addition of sodium cumol sulfonate as surface active substance increased the sensitivity of the determination by suppressing some interferences. The calibration graph was linear up to 50 µg/l Pb and the detection limit was 0.7 µg/l. RSD were 2%.
Lead Spectrophotometry FIAS-200 Interferences Optimization

"Flow Injection Fluorimetric Determination Of Nabam And Metham"
Talanta 1996 Volume 43, Issue 2 Pages 193-198
Tomás Pérez-Ruiza,*, Carmen Martínez-Lozanoa, Virginia Tomása and Rocio Casajúsa

Abstract: Cereal grain was dried in the sun for 1 h and in the shade for 24 h. The grain was ground, mixed with 0.1 M NaOH, sonicated for 10 min and centrifuged for 5 min at 2000 rpm. The filtered supernatant or diluted natural water was injected into a carrier stream (0.3 ml/min) of pre-mixed streams of 0.3 M HCl and 0.2 mM TlCl3 in 0.5 M HCl. The resulting stream passed through a reaction coil [100 cm for nebam or 150 cm for metham (metam) x 0.5 mm i.d.] and the fluorescence intensity was measured at 419 nm (excitation at 227 nm). Calibration graphs were linear for 1-10 µM-nabam and metam with RSD (n = 10) at 3 and 7 µM of 1.4 and 0.8%, respectively, for nabam and 1.2 and 0.5%, respectively, for metam. The effects of foreign substances on the analysis are tabulated and discussed. Recoveries of nabam from water were 96.6-104% and 95.75-104% from cereals with corresponding recoveries for metam of 96.6-105% and 95-101.6%.
Methylcarbamodithioic acid Nabam Fluorescence Interferences

"Chemical Speciation By Flow Injection Analysis. A Review"
Talanta 1996 Volume 43, Issue 6 Pages 825-838
Luigi Campanellaa, Krystyna Pyrzyskab and Marek Trojanowiczc,*

Abstract: A review is presented of the speciation of trace metals, complexes and organometallics in natural matrices by FIA. The advantages of using FIA are discussed. (58 references).
Metals, trace Speciation Speciation Review

"Photometric Determination Of Anionic Surfactants With A Flow Injection Analyser That Includes A Chromatomembrane Cell For Sample Preconcentration By Liquid-liquid Solvent Extraction"
Talanta 1996 Volume 43, Issue 6 Pages 819-824
L. N. Moskvina, J. Simonb,*, P. Löfflerb, N. V. Michailovaa and D. N. Nicolaevnaa

Abstract: Reagent streams of 0.125 mM methylene blue and 0.1 M sodium acetate buffer were merged and passed through a mixing coil (30 cm x 5 mm i.d.). A sample stream was then merged with the reagents and mixing was performed in a similar coil; all flow rates were 0.45 ml/min. The resulting solution passed to a chromatomembrane cell via an eight-channel 16-part multifunctional valve. The cell (cf. Moskvin and Simon, Ibid., 1994, 41, 1765) was surrounded by CHCl3. The aqueous phase flow allowed pre-concentration of the preformed ion-pair complex to occur at the phase boundary. The aqueous phase flow was stopped and the organic phase flow was started which extracted the ion-pair complex and passed to the spectrophotometer for detection at 650 nm. Anionic surfactants were determined in the range 0.02-5 mg/l in waste water. The pre-concentration mechanism is discussed.
Surfactants, anionic Spectrophotometry Sample preparation Preconcentration Chromatomembrane Solvent extraction

"Potentiometric Flow Injection Determination Of Trace Hydrogen Peroxide Based On Its Induced Reaction In Iron(III)-iron(II) Potential Buffer Containing Bromide And Molybdenum(VI)"
Talanta 1996 Volume 43, Issue 6 Pages 943-950
Nobuhiko IshibashiHiroki Ohuraa, Toshihiko Imatob,* and Sumio Yamasakia

Abstract: Sample was injected into a carrier stream (1 ml/min) of water which then merged with a reagent stream (1 ml/min) of 0.1 mM Fe(III)/Fe(II) buffer solution containing 0.4 M NaBr, 0.5% Mo(VI) and 1 M H2SO4. The resultant stream passed through a reaction coil (100 cm) to a flow-through oxidation-reduction potential electrode detector with a Ag/AgCl reference electrode and a Au-plates oxidation-reduction potential electrode. The detection limit was 0.4 µM-H2O2 with a RSD (n = 6) of 0.6% for 4 µM-H2O2. The method was applied to the determination of H2O2 in rain with recoveries of 95.8-104.1%.
Hydrogen peroxide Potentiometry

"Flow Injection Gas Diffusion Amperometric Determination Of Trace Amounts Of Ammonium Ions With A Cupric Hexacyanoferrate"
Talanta 1996 Volume 43, Issue 7 Pages 1049-1054
Renmin Liu, Bianting Sun, Daojie Liu and Ailing Sun

Abstract: Sample was injected into a carrier stream (4 ml/min) of water which then merged with a reagent stream (1 ml/min) of 0.2 M NaOH containing 0.1 M sodium citrate. The resulting stream and a stream (1.4 ml/min) of 0.1 M H2SO4 passed to a gas diffusion cell, the ammonium ions passed into the H2PO4 and were determined by amperometry using a previously described electrode (Ruzicka and Hansen, 'Flow injection Analysis', John Wiley and Sons, New York, 1981, p. 207). The flow-through three-electrode cell contained a copper hexacyanoferrate film electrode coated with Nafion Film as the working electrode, a Ag/AgCl reference electrode and a Pt auxiliary electrode. An applied voltage of 0.4 V was used. The calibration graph was linear for 2-40 µM-ammonium ions. The method was applied to the determination of ammonium ions in lake and rain water with recoveries of 94.4-104.4% and RSD of 1.1-2.3% (n not given).
Ammonium Amperometry Gas diffusion

"High-sensitivity Flow-based Analysis System Using A Semiconductor Laser And Thin Long Flow-through Cell For The Determination Of Total Phosphorus In Water"
Talanta 1996 Volume 43, Issue 9 Pages 1471-1479
Takashi Korenagaa,* and Fusheng Suna

Abstract: A flow-through cell with an optical pathlength of 10 cm machined from a 2.5 cm diameter PTFE rod (details given) was used in conjunction with a GaAlAs semiconductor laser source (emission wavelength 793 nm) and a Hamamatsu model S1087-01 photodiode detector. A light-emitting diode (Toshiba model TLS143) and a second photodiode were used to generate a reference signal. In the flow injection determination of P in water, a 300 µL portion of sample was injected into a stream of 0.3% K2S2O8 solution (600 µL/min) and the resulting mixture was passed through a reaction coil (10 m x 1 mm i.d.) at 140°C and then mixed with color reagent prepared by mixing 7.2% ascorbic acid solution with with 0.048% antimony potassium tartrate hemihydrate/1.2% ammonium molybdate tetrahydrate solution in 8% H2SO4 in the ratio 1:5. The mixture was passed through a second reaction coil (10 m x 1 mm i.d.) at 140°C and then into the detector cell. The calibration graph was linear for 1-50 µg/l of P, and for 20 µg/l of P the RSD was 1% (n = 10). The limit of detection was 0.6 µg/l and recoveries of various P compounds were 94-107%. The method was applied to eight samples of waste water, 18 samples of treated water and five samples of natural water; the results agreed with those obtained by an official method.
Phosphorus Spectrophotometry Light emitting diode Photodiode

"Analytical Methodology For Speciation Of Arsenic In Environmental And Biological Samples"
Talanta 1997 Volume 44, Issue 9 Pages 1581-1604
Marcela Burguera and JoséLuis Burguera

Abstract: A literature search on the speciation of arsenic in environmental and biological samples shows an increasing interest of many researchers in the subject. Because of the low level of arsenic species in real samples, many problems related with its speciation remain unresolved: species instability during sampling, storage and sample treatment, incomplete recovery of all species, matrix interferences, lack of appropriate certified reference materials and of sensitive analytical methods, etc. These aspects are underlined in this paper. The continued development of new analytical procedures pretending to solve some of these problems claim for an up-to-date knowledge of the recent publications. Therefore, this paper pretends to review the latest publications on the chemical speciation of arsenic, emphasizing the increasing activity in the development of accurate and precise analytical methods. In most of the cases, separation and pre-concentration is necessary, followed by element-specific detection for sensitivity improvement. Hydride generation following separation procedures (e.g., ion-exchange or high performance liquid chromatography) coupled to atomic absorption or atomic emission detectors proved to have sufficient sensitivity to monitor arsenic exposure, although restricts the analysis to hydride-forming species. Modified procedures including some kind of heating in the presence of highly oxidizing agents have proved successful to completely decompose the arsenic containing compounds to arsenate and so to extend the range of compounds which can be determined by these methods. On-line arrangements have the additional advantage of avoiding excessive sample handling, although some of them involve numerous steps and others are too costly to be recommended for routine use. The analytical figures of merits, specially detection limits are given for most of the methods in order to afford comparison and judge possible applicability. These studies, which have been approached in many different ways, would lead to knowledge that are determinant in the understanding of the cycle of this element in environment and of its physiological and toxicological behavior in the living organisms.
Arsenic Sample preparation Spectrophotometry Spectrophotometry HPLC Review Speciation

"ByT-FAS (bypass Trapped-flow Analysis System)"
Talanta 1998 Volume 45, Issue 3 Pages 493-505
Kent K. Stewart* and Stephen W. Hillard

Abstract: A new semi-automated flow analysis system called bypass trapped flow analysis system (ByT-FAS) is described. ByT-FAS gives an analyst the ability to inject sample and reagent volumes of 50-100 µL or more into flowing streams and attain phys. steady state concentrations. in the detection cell within a few seconds (<1 min) after the insertion of the sample and/or reagent. After phys. steady state is attained, the system flow is diverted around the detection cell and the reaction mixture is trapped in the detector. The concentration. of the analyte and the reagent in the detection cell can be readily computed from knowledge of the original concentrations of the analyte sample and reagents and knowledge of the flow rates of the streams propelling the analyte and the reagents. ByT-FAS was demonstrated to be useful for direct measurements of analytes in liquid solutions and for assays which utilize equilibrium. and/or kinetic chemistries to create measurable product(s) using UV/visible spectrophotometry. Enzyme activities and fundamental enzyme kinetic parameters (KMs, KIs, kcats, etc.) were determined directly. The ByT-FAS instrumentation, as described, can be used interchangeably for either equilibriumibrium or kinetic assays. It is believed that this new type of instrumentation will be of significant use for the analytical chemistry, biochemistry, molecular biology, biotechnology, environmental, pharmaceutical and medical communities.
Spectrophotometry Bypass trapped Detector Steady state Kinetic Stopped-flow

"Continuous-flow Injection Analysis Of Aqueous Environmental Samples For Chemical Oxygen Demand"
Analyst 1981 Volume 106, Issue 1263 Pages 653-662
Takashi Korenaga and Hisayoshi Ikatsu

Abstract: A method is described for the continuous, rapid determination of chemical oxygen demand (COD). The method is based on flow injection analysis (FIA) and uses acidic potassium permanganate solution as both an oxidant and a spectrophotometric reagent, and glucose as a standard. COD values for aqueous environmental samples, such as industrial wastewaters, are compared with those obtained using the Japanese Industrial Standard (JIS) method and are found to be within an error range of ±30%. The method is comparable to other manual and automatic methods and has several advantages. A sampling rate of 20 samples per hour can be achieved, and the detection limit and precision are 5 mg l-1 as COD and 0.6%, respectively. Chloride ion up to levels of 6000 mg l-1 does not interfere, even in the absence of silver salts.
Chemical oxygen demand Spectrophotometry

"Chemically Immobilized Enzyme Electrodes For Hydrogen Peroxide Determination"
Analyst 1988 Volume 113, Issue 12 Pages 1811-1815
M. Cosgrove, G. J. Moody and J. D. R. Thomas

Abstract: The electrodes were prepared by immobilizing peroxidase(I) or catalase(II) on activated nylon by the method of Mascini et al. (Anal. Chim. Acta, 1983, 146, 135). The modified net was placed over a Pt electrode for I and O electrode for II. The I-immobilized electrode was applied in a flow injection system for determination of H2O2 in which sample solution (pH 7) was injected into a carrier stream (2.0 mL min-1) of 0.1 M phosphate buffer (pH 7) and 10 mM K4Fe(CN)6 and determined at -0.1 V vs. a Ag - AgCl reference electrode. The calibration graph was rectilinear from 5.25 µM to 1.75 mM H2O2. For 17.5 and 175 µM-H2O2, the coefficient of variation were 1% (n = 10). Several compounds at concentration. of 0.1%, e.g., ethanol, acetic acid and phenol did not interfere, but formaldehyde and ascorbic acid did. The II-immobilized electrode was applied in the dip-type mode to determine H2O2 in 0.1 M Tris buffer (pH 10). The calibration graph was rectilinear from 6.96 µM to 2.63 mM H2O2, and at 700 µM the coefficient of variation was 3% (n = 12). The storage and lifetime of the electrodes are discussed, and industrial and environmental applications are proposed.
Hydrogen peroxide Amperometry Electrode Apparatus Detector Interferences Immobilized enzyme

"Fountain Cell: A New Tool For Chemiluminescence Analysis By Flow Injection"
Analyst 1994 Volume 119, Issue 5 Pages 975-979
D. J. Tucker, B. Toivola, C. H. Pollema, J. Ruzicka and G. D. Christian

Abstract: A sequential injection analysis system consisting of a peristaltic pump and multi-position valve for fluid handling, and a fountain cell directly coupled to an end-on photomultiplier tube as the detector is described (diagram given). Optimum conditions for sequential injection analysis involving three overlapping zones were deduced and the analytical utility of the system was demonstrated by the chemiluminescence determination of H2O2 and glucose, both analyzes based on the luminol reaction. The system has minimum reagent consumption and can be evaluated without any reconfiguration of the equipment or reagents involved in a given analysis.
Hydrogen peroxide Glucose Chemiluminescence Sequential injection Fountain cell Reagent consumption

"Response Surfaces For The Determination Of Arsenic(III) By Hydride Generation Atomic Absorption Spectrometry And Flow Injection"
Analyst 1994 Volume 119, Issue 6 Pages 1403-1411
Peter D. Wentzel, Nils G. Sundin and Cristel Hogeboom

Abstract: Response surfaces for the determination of As(III) by flow injection hydride generation AAS are reported as a function of pH and tetrahydroborate concentration for several buffers such as acetate, formate, propanoate, butanoate, citrate, phosphate and HCl. Response surfaces were obtained with an automated continuous-flow apparatus under computer control and an efficient experimental design based on continuous variations. The instrumentation and software are described. The response surfaces obtained demonstrated unexpected behavior for the pH dependence of sensitivity in the determination of As(III). The nature of the buffer was important in determining the pH dependence of the method. Results are discussed.
Arsenic(3+) Spectrophotometry

"Shipboard Determination Of Dissolved Cobalt In Seawater Using Flow Injection With Catalytic Spectrophotometric Detection"
Analyst 1996 Volume 121, Issue 8 Pages 1037-1041
Alexander Malahoff, Irina Ya. Kolotyrkina and Lilly K. Shpigun

Abstract: Seawater was filtered and acidified to pH 2. A portion (200 µL) was injected into a carrier stream of acidified seawater depleted of Co at a flow rate of 1.5 ml/min and mixed with a reagent stream of 0.01 M N,N'-diethyl-p-phenylenediamine/0. 01 M Tiron at a flow rate of 0.8 ml/min. The combined reagent/sample stream was merged with a stream of 0.2% H2O2/0.04 M NaOH/0.02 M sodium tetraborate at a flow rate of 0.6 ml/min. The mixture was passed through a 2.2 m reaction coil maintained at 30°C; absorbance was measured at 554 nm. A diagram of the manifold used is given. The calibration graph was linear from 0-300 ng/l Co; the detection limit was 1 ng/1. RSD was 1.6-10.6% (n = 5). Recoveries were 101-113% Co. The throughput was 50 samples/h.
Cobalt Spectrophotometry Tiron Heated reaction

"Determination Of Lead In Soil Samples By In-valve Solid-phase Extraction - Flow Injection Flame Atomic Absorption Spectrometry"
Analyst 1996 Volume 121, Issue 10 Pages 1413-1417
Ponlayuth Sooksamiti, Horst Geckeis and Kate Grudpan

Abstract: Soil (0.3 g) was digested with 5 mL concentrated HNO3 and 1 mL 30% H2O2 in a microwave digester at 250-650 W for 20 min. The digest was filtered and diluted to 100 mL with 1 M HNO3. A portion of the resulting solution was loaded (4 ml/min) onto a column (2.5 cm x 3 mm i.d.) of Sr. Spec SPS resin (Eichrom), which was incorporated in a flow injection system. Elution of Pb from the column was effected with 0.05 M ammonium oxalate (4 ml/min). The eluate was analyzed for Pb by flame AAS at 217 nm. The calibration graph was linear up to 5 µg Pb, the detection liwas 0.08 µg and the RSD (n = 15) was 4.1%. The recovery of Pb was 95-98%. The results obtained agreed with those obtained by ETAAS.
Lead Sample preparation Spectrophotometry Sample preparation Method comparison Resin Solid phase extraction Preconcentration

"Multicomponent Analysis By Flow Injection Using A Partial Least-squares Calibration Method. Simultaneous Spectrophotometric Determination Of Iron, Cobalt And Nickel At Sub-ppm Levels"
Analyst 1996 Volume 121, Issue 11 Pages 1609-1612
Carlos Moreno, Manuel P. M&aacute;nuel-Vez, Inmaculada G&oacute;mez and Manuel Garc&iacute;a-Vargas

Abstract: Sample (136 µL) was injected into a reagent stream (1 ml/min) of 0.02% 2,2'-di-pyridyl ketone picolinoylhydrazone/0.05% ascorbic acid in 0.02 M acetate buffer of pH 4.9 in a flow injection manifold (schematic shown). The mixture was passed through a 130 cm coil and the absorbance was recorded spectrophotometrically at 367, 410 and 385 nm, respectively, for Fe, Co and Ni with corresponding epsilon of 6640, 3890 and 5170. A partial least-squares calibration method was applied to the data in order to determine the Fe, Co and Ni concentrations in the sample. The method was applied to a washing solution used in an automotive factory and to a waste acidic mine effluent. Results obtained agreed well with those obtained by AAS or ICP-AES.
Cobalt Iron Nickel Spectrophotometry Method comparison Partial least squares Buffer

"Catalytic Determination Of Dissolved Inorganic Carbon In Natural Waters By Flow Injection Spectrophotometry"
Analyst 1996 Volume 121, Issue 11 Pages 1617-1619
Nelson Maniasso, Sandra Sato, Maria F. Gin&eacute; and Antonio O. Jacintho

Abstract: Sample was aspirated (2 ml/min) so as to fill a 750 µL sampling loop. The loop contents were injected into a carrier stream (1.6 ml/min) of 30 mg/l silicate of a flow injection manifold (schematic shown). The sample zone was merged successively, with reagent streams of 0.5 M acetate buffer of pH 5 (0.4 ml/min), Cr(III) (3 g/l aged for 10 days before use; 0.4 ml/min) and 0.3 M EDTA (0.4 ml/min). The mixture was passed through a 200 cm coil maintained at 45°C and the absorbance was measured at 540 nm. The calibration graph was linear for 10^-300 mg/l dissolved inorganic carbon (as hydrogencarbonate). The RSD (n = 9) at the 50 mg/l level was The throughput was 36 samples/h. The method was applied to lake, river, well and tap water. The results obtained agreed with those obtained by titrimetry.
Carbon, inorganic Spectrophotometry Buffer Method comparison Heated reaction Catalysis

"Solid-phase Extraction Coupled With Electrochemical Detection For The Determination Of The Herbicide Bromofenoxim In Water Samples At Low- And Sub-micro G 1-1 Levels"
Analyst 1996 Volume 121, Issue 12 Pages 1839-1843
Irena Grabec vegl, Boidar Ogorevc, Milko Novi and Emilio Benfenati

Abstract: A sample (100-250 ml) was adjusted to pH 3 with HClO4 and pumped through a C18 Polar Plus silica gel SPE cartridge, previously conditioned with acetonitrile/H2O then dried. For square-wave voltammetric detection, bromofenoxim (I) was eluted with 10 mL acetonitrile containing 0.1 M LiClO4. The eluate was analyzed directly at a static Hg drop electrode by applying a depoon potential of -0.1 V vs. Ag/AgCl for 10 s followed by a potential scan to -0.8 V, at 175 Hz, a pulse amplitude of 30 mV and a potential step of 10 mV. For FI amperometric detection, I was eluted with 10 mL 20% aqueous acetonitrile containing 0.1 M LiClO4 (solution A). A portion of eluate (40 µL) was injected into a carrier stream of solution A at a flow rate of 0.5 ml/min. Detection was at an in situ prepared Hg-film eous C electrode at -0.7 V vs. Ag/AgCl. For square-wave voltammetric detection, the calibration graph was linear from 0.2-12 µg/l I; the detection limit was 0.05 µg/l. Recovery was 92% and RSD was 6% (n = 6). For FI amperometric detection, the calibration graph was linear from 3-120 µg/l I; the detection limit was 1.5 µg/l. The recovery was 121% and RSD was 9% (n = 7). The methods were applied to tap water.
Bromofenoxim Amperometry Sample preparation Solid phase extraction

"Electrothermal Atomic Absorption Spectrometry In Occupational And Environmental Health Practice - A Decade Of Progress And Establishment. A Review"
J. Anal. At. Spectrom. 1994 Volume 9, Issue 3 Pages 405-414
Dimiter L. Tsalev

Abstract: A review is presented of developments in the determination of 52 elements by the cited technique. Instrumentation, chemical modifiers, reaction media, sample decomposition, atomizer design, fast temperature programmes, in-situ ashing, flow injection pre-concentration and element speciation are critically discussed with respect to occupational and environmental health applications. (170 references).
Trace elements Spectrophotometry Review Preconcentration Speciation

"Determination Of Arsenic In Environmental And Biological Samples By Flow Injection Inductively Coupled Plasma Mass Spectrometry"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 1 Pages 31-35
Meng-Fen Huang, Shiuh-Jen Jiang and Chorng-Jev Hwang

Abstract: A simple and very inexpensive in situ nebulizer-hydride generator was used with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of arsenic in environmental and biological samples. The application of hydride generation (HG)-ICP-MS alleviated the spectral interferences and sensitivity problems of arsenic determinations encountered when conventional pneumatic nebulization is used for sample introduction. The sample was introduced by flow injection to minimize deposition of solids on the sampling orifice. The arsenic in the sample was reduced to As(III) with L-cysteine before being injected into the HG system. A detection limit of 0.003 ng ml-1 was obtained for arsenic. The method has been successfully applied to the determination of arsenic in National Research Council of Canada reference materials, CASS-2 (Nearshore Seawater Reference Material for Trace Metals), NASS-3 (Open Ocean Reference Material for Trace Metals) and SLRS-2 (Riverine Water Reference Material for Trace Metals), and in National Institute of Standards and Technology, Standard Reference Material 2670, Toxic Metals in Freeze-Dried Urine. Precision was less than 5% and analysis results were within 6% of the certified values for all determinations.
Arsenic Mass spectrometry Volatile generation Volatile generation

"Comparative Analysis Of Aluminum Oxide Powders By Inductively Coupled Plasma-mass Spectrometry With Low And High Mass Resolution"
J. Anal. At. Spectrom. 1996 Volume 11, Issue 9 Pages 797-803
Norbert Jakubowski, Wolfgang Tittes, Dagmar Pollmann, Dietmar Stuewer and Jos&eacute; A. C. Broekaert

Abstract: ICP-MS with low and moderate mass resolution was applied to the determination of trace elements (B, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Ba, La and Ce) in two different pare Al2O3 powders after decomposition. Four different sets of measurements were performed: (1) with quadrupole instrument in standard operation; (2) with the same instrument including an online matrix trace separation step; (3) with a double-focusing magnetic field instrument operated at;low resolution (R=300); and (4) with the same instrument operated with moderate resolution (R=3000). Generally, the quantitative results obtained with the four different techniques are in good agreement. Application of the double-focusing instrument with moderate mass resolution permitted the determination of spectrally interfering elements such as V, Cr, Mn, Fe and Ga in Al2O3 in the 0.04-10 µg g-1 range far above the detection limit. For all four applied techniques, blank values arising from the reagents and instrumentation were a major limitation for a number of elements, and the lowest detection limits were obtained in each instance for elements that do not suffer from limitations due to blank values.
Trace elements Boron Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Zirconium Barium Lanthanum Cerium Mass spectrometry Interferences Method comparison

"Evaluation Of Controlled-pore Glass-immobilized Iminodiacetate As A Reagent For Automated Online Matrix Separation For Inductively Coupled Plasma Mass Spectrometry"
J. Anal. At. Spectrom. 1996 Volume 11, Issue 10 Pages 907-912
Simon M. Nelms, Gillian M. Greenway and Dagmar Koller

Abstract: A 0.04 g portion of PROSEP Chelating-1 iminodiacetate reagent (Bioprocessing, Consett, Co. Durham, UK) was packed as dry powder into a glass column (2.5 cm x 3 mm) that was incorporated in a flow injection manifold (diagram presented). A 3 mL sample was injected into a stream of H2O; transition-metal, U and Pb cations were retained on the column and subsequently eluted in an elution volume of 0.3 mL with 0.5 M HNO3. Calibration graphs prepared on the basis of water and seawater as matrices agreed, and both sets showed good linearity. RSD (n = 5) at 5 ng/ml were 5%, and recoveries were 62-113% for all the metals except Mn (35%).
Metals, heavy Mass spectrometry Controlled pore glass Iminodiacetate

"Fluorimetric Measurement Of Aqueous Ammonium Ion In A Flow Injection System"
Anal. Chem. 1989 Volume 61, Issue 5 Pages 408-412
Zhang Genfa and Purnendu K. Dasgupta

Abstract: The test solution (14 µL), containing NH3 or NH4+, is injected into a carrier stream (50 µL min-1) of water freed from NH3 and NH4+ by cation exchange, and the stream is mixed with 10 mM phthalaldehyde in aqueous 25% methanol (50 µL min-1) in a knotted coil and then with 3.0 mM Na2SO3 in 0.1 M phosphate buffer of pH 11.0 (50 µL min-1). The mixture is heated for ~40 s in a stainless-steel coil at 85°C (unnecessary at high NH4+ concentration.) and its fluorescence is measured at >425 nm (excitation at 351 nm). The detection limit is better than 20 nM-NH4+. The method is unaffected by NaCl concentration, and response to amino-acids is slight. The method has been used to determine NH4+ in tap- and lake water and rain.
Ammonium Fluorescence Buffer Interferences Detection limit Knotted reactor Selectivity Method comparison

"Pulsed Sample Introduction Interface For Combining Flow Injection Analysis With Multi-photon-ionization Time-of-flight Mass Spectrometry"
Anal. Chem. 1992 Volume 64, Issue 7 Pages 769-775
Alan P. L. Wang and Liang Li

Abstract: Sample molecules carried by a liquid carrier (e.g., methanol at 0.5 mL min-1) were vaporized by passage through a heated capillary tube to form aerosol droplets which were entrained in the sample vaporizer of a high-temp. pulsed nozzle. The vapor was injected into the time-of-flight mass spectrometer at a repetition rate determined by the ionization source. The interface described was used to detect both volatile and non-volatile compounds, including those of environmental and biological significance. The average coefficient of variation was 4 to 8%. There were no memory effects or severe peak tailing, and cluster formation during supersonic jet expansion was not a problem. The detection limits for aniline, tryptamine and indole-3-acetic acid were 3, 4 and 140 ng, respectively. The calibration graphs were rectilinear over two-orders of magnitude of analytical range. A pulsed sample introduction (PSI) interface is developed to combine flow injection analysis with a time-of-flight mass spectrometer. In PSI, sample molecules carried by a liquid carrier such as methanol at a flow rate of 0.5 mL/min are vaporized by passing through a heated capillary tube and then through a sample vaporizer of a high-temp. pulsed nozzle. The resulting sample vapors are introduced into the mass spectrometer in a pulsed form and ionized by laser-induced multiphoton ionization. The applicability of this interface for the detection of volatile and nonvolatile compounds is studied. It is found that a variety of chemicals including molecules with environmental or biological significance can be studied by this method. Preliminary studies of the performance of this interface are reported. It is shown that reproducible results from repeated injection of the same concentration. of samples can be readily obtained. The average relative standard deviation is in the range of 4-8%. No memory effects and severe peak tailing are found with this PSI interface. The detection limits of the present technique are compound dependent. For aniline, tryptamine, and indole-3-acetic acid, the detection limits are found to be 3, 140, and 4 ng, respectively. Excellent linearity over two orders of magnitude of analytical range can be obtained for quantitation. It is also shown that cluster formation during the supersonic expansion is not a major problem in this technique.
Methanol Mass spectrometry Interface Apparatus Optimization

"Environmental Analytical Chemistry At Jekyll Island"
Anal. Chem. 1993 Volume 65, Issue 17 Pages 759A-761A
Wach, F.

Abstract: The 23rd International Symposium on Environmental Analytical chemistry was held on Jekyll Island, off the coast of Georgia, on June 14-16, 1993. The hundred or so delegates representing government, academia, and industry heard presentations on a range of topics, including indoor air analysis, the importance of determining the chirality of environmental contaminants, and a new separation technique that integrates capillary electrophoresis, sample injection, and flow injection analysis on a glass chip.

"Novel Membraneless Amperometric Peroxide Biosensor Based On A Tetrathiafulvalene-p-tetracyanoquinodimethane Electrode"
Anal. Chem. 1994 Volume 66, Issue 4 Pages 510-515
Ulrich Korell and Ursula E. Spichiger

Abstract: A PTFE disc with a central 1 mm hole was press-fitted into a length of Kel-F tubing (4 mm i.d.), leaving a cavity 3 mm deep. This cavity and the central hole were filled with a paste of tetrathiafulvalene-p-tetracyanoquinodimethane (organic conductor)/high temperature silicone oil (5:8) and the surface of the paste was smoothed flat. Electrical contact with the paste was with a Pt wire and the electrode was attached to a stirrer. The enzyme peroxidase (5 mg) was made lipophilic by reaction with caprylic aldehyde (0.1 ml) and the mixture was dried in a vacuum desiccator. The product was dispersed in 0.1 mL of 0.1 M sodium pyrophosphate buffe of pH 6 and a 10 µL portion was applied to the paste electrode and allowed to dry in air. The electrode was mounted in a 100 mL cell with a Ag/AgCl reference electrode and a Pt counter electrode. All solution were made in the same buffer, kept at 25°C and stirred with the working electrode at 25 rpm. Current from the reduction of H2O2 was measured at -0.5 V. The working range was 0.01-4 µM-H2O2 but the response decreased over time due to intermittent exposure to open-circuit conditions; it was more stable in a flow injection system. Response time was ~10 s.
Hydrogen peroxide Electrode Electrode Sensor Amperometry

"Non-linear Multi-component Kinetic Analysis For The Simultaneous Stopped-flow Determination Of Chemiluminescence Enhancers"
Anal. Chem. 1994 Volume 66, Issue 7 Pages 988-993
Aurora Navas Diaz and Jose Antonio Gonzalez Garcia

Abstract: The theory of kinetic analysis with the measured parameter as the independent variable is outlined. This principle was applied in a stopped-flow procedure at 20°C in which one syringe contained 0.9333 M NaOH/0.2 mM EDTA/0.4 mM ferricyanide and the other contained 6.7 µM-luminol and the analyte (50-500 nM-protocatechuic or 0.1-1 µM-caffeic acid). Mixtures were analyzed similarly with a luminol concentration of 2.5 µM. The chemiluminescence data were processed by orthogonal factorization with use of PC-MATLAB software (MatWorks, Sherborn, MA). The chosen parameters were the chemiluminescence at 0.3 s and the initial reaction rate. Synergy occurred when two or more enhancers acted simultaneously, and surface response methodology was used to model the data. Response based on initial reaction rate was linear for 25-250 nM-protocatechuic and 50-500 nM-caffeic acid, and the RSD of each measurement (n = 3) was 0.2-1.9%. Analogous batch analyzes showed high calibration errors.
Caffeic acid Protocatechuic acid Chemiluminescence Stopped-flow Kinetic

"Novel Technique To Reduce Electrical Inference Inherent In Laser-enhanced Ionization Detection By Using Flow Injection Analysis"
Anal. Chem. 1994 Volume 66, Issue 13 Pages 2180-2186
Shau-Chun Wang and King-Chuen Lin

Abstract: Aqueous solutions of In containing 0.1-50 ppm of Na were nebulized at 4.5 mL/min into an acetylene-air flame. Analytes were ionized with a tunable dye laser, pumped by a Nd:YAG laser at 532 nm, and doubled through a KDP crystal with 325.62 nm emission. Data collection was achieved under non-optimum conditions with two metal rod electrodes suspended in the vicinity of the flame, one electrode being biased at -1000 V, the other linked to a current-to-voltage current amplifier. Calibration graphs were linear up to 10 ppm of In in matrices containing 0-2 ppm of Na. Analyses of a synthetic sample containing 2 ppm of In and 1 ppm of Na had a RSD of 3.6% (n = 3). Comparative analyzes were performed using FIA with carrier solutions of the analyte/matrix being analyzed with a 250 µL injection of water. In this case, calibration graphs were linear over same range, but with a greater amount of tolerated matrix (from 4-40 ppm of sodium). Results are discussed.
Indium LIBS

"Solenoid Pumps For Flow Injection Analysis"
Anal. Chem. 1996 Volume 68, Issue 15 Pages 2717-2719
Debra A. Weeks and and Kenneth S. Johnson

Abstract: The peristaltic pump of a typical FIA system was replaced by three solenoid-driven diaphragm pumps with integral Viton check valves. These pumps had the ability to incorporate microprocessor control of the reagent and sample streams independently. The system was tested by the determination of nitrite in water and seawater. Reduced detector oscillations were achieved with a 140 µL flow cell, a 1 m reaction coil and a 100 µL injection loop. Detection limits were M-nitrite, the RSD was 1% for 10 µM-nitrite and 60 injections/h were possible with flow rates of 0.5 ml/min for reagents and sample. These values match the performance of the conventional FIA system.
Nitrite

"Photometry In A Continuous-flow System. Determination Of Sulfate In A Continuous-flow System In Environmental Samples With Dimethylsulfonazo(III)"
Fresenius J. Anal. Chem. 1979 Volume 295, Issue 2 Pages 122-124
H. F. R. Reijnders, J. J. van Staden, and B. Griepink

Abstract: Sulphate in various environmental samples was determined by measuring the optical absorbance upon reaction with the barium(II) dimethylsulphonazo(III) complex. The measurement took place in a flow-through system. Interferences from phosphate, metal ions and others were eliminated. The results of a turbidimetric measurement, a spectrophotometric measurement with thorin, an automatic titration and the proposed method are compared. The latter allows the determination of sulphate in the range of 1.4-60 µmol L-1. The standard deviation is 0.3-0.6 µmol L-1, depending on the type of sample (water) analyzed. A determination takes 1.5 min.
Sulfate Spectrophotometry Interferences Method comparison

"Determination Of Arsenic, Antimony, Bismuth, Selenium And Tin In Biological And Environmental Samples By Continuous-flow Hydride-generation ICP-AES Without Gas-liquid Separator"
Fresenius J. Anal. Chem. 1991 Volume 340, Issue 1 Pages 41-47
P. Schramel and Li-Qiang Xu

Abstract: Arsenic, Sb, Bi, Se and Sn were simultaneously determined in samples by ICP-AES with use of the cited hydride-generation system (diagram given) at 1.5 kW. Samples were digested (i) under pressure with 70% HNO3 in a closed vessel at 170°C for 10 h and (ii) with HNO3 - ClHO4 - H2SO4 (details given). Sample solution in 30% HCl - 20% HNO3 were mixed with a reductant solution consisting of 3% NaBH4 and 2% KI prior to nebulization in the ICP spectrometer and determination by AES. Interferences caused by Cu and Ni ions were eliminated with use of the reductant. In general results were in good agreement with certified values; detection limits were at the ng level.
Antimony Arsenic Bismuth Selenium Tin Sample preparation Spectrophotometry Interferences Nebulizer Reference material

"Determination Of Six Arsenic Species By High Performance Liquid Chromatography-hydride Generation-atomic Absorption Spectrometry With Online Thermo-oxidation"
Fresenius J. Anal. Chem. 1993 Volume 346, Issue 6-9 Pages 643-647
M. A. L&oacute;pez, M. M. G&oacute;mez, M. A. Palacios and C. C&aacute;mara Contact Information

Abstract: Anion-exchange HPLC has been coupled to online thermo-oxidation and hydride generation-atomic absorption spectrometry (HG-AAS) for the speciation of As(V), As(III), MMA, DMA, AsB and AsC. The thermoreactor consists of a loop of PTFE tubing dipped in a powdered-graphite oven heated to + 140°C. Samples and persulfate solution run together into the thermo-reactor. The thermo-oxidation conditions were optimized using a FIA system. The chromatographic and chemical parameters affecting hydride generation efficiency were optimized. The overlap of the As(III) and AsB peaks made it necessary to determine AsB as the difference between absorbance in the presence and in the absence of thermo-oxidation. The thermo-conversion efficiencies were above 96%. Recoveries were around 100% and detection limits below 1 ng. The proposed method is rapid, sensitive and precise (RSD about 5%), making it suitable for online determination in environmental samples.
Arsenic(3+) Arsenic(5+) Arsenoβine Monomethylarsine Dimethylarsenic Arsenocholine HPLC Spectrophotometry Interface Heated reaction Volatile generation Optimization Speciation Volatile generation

"Analysis Of Standard Reference Materials After Microwave-oven Digestion In Open Vessels Using Graphite Furnace Atomic Absorption Spectrophotometry And Zeeman-effect Background Correction"
Fresenius J. Anal. Chem. 1993 Volume 347, Issue 6-7 Pages 233-237
D. Chakraborti, M. Burguera and J. L. Burguera

Abstract: Heating-covered teflon digestion vials located inside a reheatable container in the presence of different acid mixtures with microwave oven dissolve the metals from biological and environmental certified reference materials. Pb, Cd, Cu, Mn and Fe from the dissolved samples are determined by graphite furnace atomic absorption spectrophotometry and Zeeman-effect background correction. The method allows the treatment of about 100 samples per operation. [References: 10]
Lead Cadmium Copper Manganese Iron Sample preparation Spectrophotometry Reference material

"The Wickbold Combustion Method For The Determination Of Mercury Under Statistical Aspects"
Fresenius J. Anal. Chem. 1994 Volume 349, Issue 7 Pages 502-509
D. Erber, L. Quick, F. Winter, J. Roth and K. Cammann

Abstract: The Wickbold combustion method was used in the decomposition of environmental materials for the determination of Hg with use of a Perkin Elmer flow injection - cold vapor AAS analysis system. The method was applied to eight standard reference materials and the data were analyzed using a range of statistical procedures that are recommended for equality assurance purposes. For sample portions containing 1000 µg of Hg it was possible to decompose organic and inorganic samples quantitatively. The limit of detection was 2 µg/kg of Hg with a sample portion of 10 g.
Mercury Spectrophotometry Sample preparation Reference material

"Flow Injection Analysis - Spectrophotometric Determination Of 8-hydroxyquinoline With P-aminophenol"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 2 Pages 216-220
B. A. Hasan A, K. D. Khalaf A, A. Morales-Rubio A, M. de la Guardia

Abstract: A 10 mL portion of 1 M NaOH was added to 8-hydroxyquinoline (quinolin-8-ol; I) prepared in HCl of pH 3, or in KCl/H3BO3/NaOH buffers of pH 8 or 10 and the total volume was diluted to 25 mL. Streams (3.2 ml/min) of p-aminophenol (PAP) (100 µg/ml) and 0.004 M KIO4 were mixed in a reactor coil (45 cm x 0.8 mm i.d.) and the benzoquinoneimine, formed in situ fed into a second reactor coil (400 cm x 0.8 mm i.d.) with 0.4 M NaOH (3.2 ml/min) into which a 500 µL portion of I in an appropriate buffer had been injected. The resultant indophenol dye (structure illustrated) was measured at 610 nm in a 50 µL flow cell (1 cm path). The calibration graph was linear from 2-8 µg/ml I and the detection limit was 7.6 ng/ml. The RSD (n = 4) was 0.06% for 4 µg/ml I. Recoveries of 98-102% were obtained at pH 3, 8 or 10. Sensitivity is lower (ε = 9500) for the reaction of I with PAP than reported for batch procedures which employ reactions of I with orthanilic acid (ε = 26 500) or diazotized 4-aminoacetophenone (ε = 33 700).
8-Quinolinol Spectrophotometry Buffer

"Trace Enrichment And Measurement Of Platinum By Flow Injection Inductively Coupled Plasma Mass Spectrometry"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 4 Pages 420-423
M. M. Hidalgo, M. M. G&oacute;mez Contact Information and M. A. Palacios

Abstract: Solutions of PdCl4 in 0.01 M HNO3 of pH ~2.3 were pumped (3 ml/min) via a manifold through 0.025 g activated Al2O3 (63-200 µm) in a Teflon tube (7 cm x 1.5 mm i.d.). The concentrated Pd ions were eluted (1 ml/min) with 50 µL 2 M NH4OH and nebulized with Ar (32 psi) into an ICP operated at 1150 W r.f. forward power and 27.12 MHz. Cooling and auxiliary Ar flows were 14.41 l/min. MS measurements were made in the platinum-193 peak-jumping mode at 8.3 x 10^-5 mbar and dwell time 1000 ms. A nominal pre-concentration factor of 600 was achievable. Calibration graphs (ion intensity of net peak height) displayed good linearity for 0-250 ng/l Pt. The RSD (n = 5) for 100 ng/l Pt, with a 5 min sampling time was 4%. Detection limits were 4 ng/l and 2 ng/l with 5 and 10 min sampling times, respectively. The procedure was assessed for Pt(IV) in natural waters, motor car exhaust and common analytical reagents.
Platinum Mass spectrometry Preconcentration Activated alumina

"Online Column Preconcentration For The Determination Of Cobalt In Seawater By Flow Injection Chemiluminescence Detection"
Fresenius J. Anal. Chem. 1996 Volume 355, Issue 5-6 Pages 676-679
Shizuko Hirata, Yukimasa Hashimoto, Masato Aihara and G. Vitharana Mallika

Abstract: Seawater (100 ml) was adjusted to pH 3.6 with 0.5 mL formic acid/ammonium formate buffer then passed through a fluoride-containing metal alkoxide glass column (3 cm x 4 mm i.d.) of 8-quinolinol immobilized on silica gel for 2 min at a flow rate of 3 ml/min, with 0.05 M HCl as carrier stream at a flow rate of 1.7 ml/min. Most heavy metals were separated except Fe(III), but it did not interfere when the gallic acid/H2O2 method was used: water was passed through the column to remove alkali and alkaline earth metals, then the eluate was passed in the reverse direction at a flow rate of 1.7 ml/min and mixed with gallic acid and NaOH both flowing at 0.76 ml/min. The mixture was heated to 60°C in a 2 m reaction coil and the chemiluminescence intensity was measured. The calibration graph was linear from 0.6 ng/l to 1 µg/l Co. The detection limit was 0.62 ng/l Co for a 6 mL sample; RSD was 2.1% (n = 10) for 10 ng/l Co(II). Results from the analysis of reference seawater samples agreed with the certified values.
Cobalt Chemiluminescence Interferences Reference material Preconcentration Silica gel Heated reaction

"Selective Detection Of Metal Species In HPLC And FIA By Means Of Pulsed Amperometric Detection"
Fresenius J. Anal. Chem. 1996 Volume 356, Issue 3-4 Pages 242-246
G&uuml;nther Weber

Abstract: Standard solutions of Sn(IV)/rutin or Pt(II)/glutathione complexes were prepared and analyzed by HPLC on a Spherisorb ODS II column (10 cm x 4.6 mm) with 0.1 M acetate buffer of pH 4.5/methanol (3:2) as mobile phase (1 ml/min) and triple-step pulsed amperometric detection at +800, +1000 and -500 and +250, +800 and -600 mV, respectively, for Sn(IV) and Pt(II). The optimum potentials, time intervals and time delays for each system were reported. Calibration graphs were linear up to 200 and 2000 ng/ml, respectively, for Sn(IV) and Pt and the corresponding detection limits were 8 and 20 ng/ml. The method was also applied for the analysis of fruit juice and grass extract.
Tin Platinum HPLC Amperometry Sample preparation Optimization

"Reactive Electrode (reactrode) For The Voltammetric Determination Of Heavy Metals In Laboratories And For Use As A Passive Monitor In Remote Analysis"
Fresenius J. Anal. Chem. 1996 Volume 356, Issue 3-4 Pages 237-241
I. Helms and F. Scholz

Abstract: The electrode was prepared by heating a mixture of graphite powder (0.45 g), HYPHAN cellulose (0.25 g) and paraffin (0.45 g) and pressing the resulting paste into rods of diameter 0.5 mm. In the batch analysis technique, the metal ions were accumulated from a medium of pH 6 at open-circuit potential for 15 min. The electrode was transferred to an electrochemical cell containing 0.1 M KNO3/0.1 M acetic acid (20:1). A potential of -1.2 V (vs. Ag/AgCl) was applied for 250 s. Anodic stripping was effected by differential pulse voltammetry using a pulse amplitude of 50 mV. Detection limits for Pb, Hg and Cu were 0.11 µM, 50 nM and 0.24 µM, respectively. Of the cations investigated, only Fe(III) interfered. The method was also applied for FIA systems.
Metals, heavy Voltammetry Electrode Interferences Remote instrument

"Semi-automatic Determination Of Tin In Marine Materials By Continuous-flow Hydride-generation Inductively Coupled Plasma Atomic-emission Spectrometry"
Fresenius J. Anal. Chem. 1997 Volume 357, Issue 7 Pages 822-826
Yong-Lai Feng, H. Narasaki, Hong-Yuan Chen, Li-Ching Tian

Abstract: Sample (1.25 g) was equilibrated overnight with 15 mL 68% HNO3 and 2 mL 70% HClO4, then digested by heating with 0.5 mL concentrated H2SO4. The resulting solution was adjusted to pH 3.5 with 4 M NaOH and passed through a DIAION SA 10A anion-exchange resin column (15 cm x 8 mm i.d.; Mitsubishi Kasei Corp., Tokyo, Japan). The eluate was mixed with 3.5 mL 3 M H2SO4 and 2.5 mL 10% L-cysteine hydrochloride monohydrate, diluted to 25 mL and then analyzed for Sn by continuous-flow hydride-generation ICP-AES at 189.93 nm (operating conditions given). The detection limit was 0.4 ng/mL Sn and the RSD (n = 10) was 0.5%. The effects of varying the H2SO4, NaBH4 (hydride-generating reagent) and NaOH concentrations, Ar (carrier gas) and NaBH4 flow rates and the ratio of flow rates of sample solution and NaBH4 were investigated (results presented). The effects of interferents were also investigated, along with seven methods for masking interference (results tabulated). The method was applied to an environmental (marine) CRM. The result agreed with the certified value and the RSD (n = 6) was 0.95%.
Tin Ion exchange Sample preparation Spectrophotometry Column Detection limit Interferences Reference material

"Application Of An Online Preconcentration System In Simultaneous ICP-AES"
Microchim. Acta 1992 Volume 106, Issue 3-6 Pages 191-201
Peter Schramel, Li -Qiang Xu, G&uuml;nter Knapp and Markus Michaelis

Abstract: A PC-controlled online pre-concentration system (TRACECON) was connected to a JY-70 Plus simultaneous inductively coupled plasma (ICP) spectrometer to pre-concentrate online seven trace elements (Cu, Fe, Zn, Cr, Ni, Mn, V) in biological and environmental samples. EDTrA-cellulose was used as column material. The elemental concentrations were determined by simultaneous ICP-AES. The effect of pH of the sample solution on the enrichment was studied. It was found that the recoveries of chromium and iron depend strongly on the pH of the sample solution. All the elements mentioned were recovered quantitatively at pH 4.0. The flow rates of sample solution and element solution were optimized. The enrichment factors for seven elements at 5 mL loading volume range from 3.9 for Cu to 7.9 for Zn. The detection limits of all seven elements were improved. The accuracy of the method was tested by the analysis of a number of CRMs of NIST, BCR and NIES. Most results are in good agreement with the certified values.
Copper Iron Zinc Chromium Nickel Manganese Vanadium Spectrophotometry Computer Reference material Preconcentration Column Optimization pH

"New Developments In Flow Injection Vapor Generation Atomic Absorption Spectrometry"
Microchem. J. 1996 Volume 53, Issue 1 Pages 42-53
Fang Zhaolun a, Tao Guanhonga, Xu Shukuna, Liu Xuezhua and Wang Jingb

Abstract: A review is presented of the enhancements in sensitivity and selectivity brought about by new developments in flow injection techniques for combined FI-vapor generation AAS. In particular, selectivity enhancements by (i) optimization of FI parameters and reaction conditions, (ii) online separation of interferents and (iii) online sample matrix modification as well as sensitivity enhancements by (i) reagent addition, (ii) online coprecipitation pre-concentration and (iii) in situ pre-concentration of hydrides in a graphite furnace are discussed in detail. The enhancements are illustrated by applications in the trace or ultratrace determination of Ge, Se, As, Sb, Bi, Sn and Pb in environmental materials and Chinese herbal medicines. (28 references).
Trace elements Spectrophotometry Interferences Review Coprecipitation Optimization Preconcentration Ultratrace

"Determination Of Vanadium By Its Catalytic Effect On The Oxidation Of Gallocyanine With Spectrophotometric Flow Injection Analysis"
Microchem. J. 1996 Volume 53, Issue 2 Pages 139-146
Ali A. Ensafi and A. Kazemzadeh

Abstract: Portions (200 µL) of standard V solutions were injected into a carrier stream of water at 0.5 ml/min delivered by a 12-channel peristaltic pump in a flow injection system (schematic shown). The sample-containing carrier stream was mixed sequentially with streams of 3.5 µM-gallocyanine (I) in a citrate buffer of pH 4 and 0.9 M NaBrO4 solution (both at 0.5 ml/min) in a 250 cm reaction coil. The decrease in the absorbance of I resulting from its V-catalyzed oxidation by bromate was measured at 620 nm. The calibration graph was linear from 0.01-100 ng/ml of V(V) [0.002-20 ng/200 µL solution] and the detection limit was 0.001 ng/200 µL. RSD (n = 10) were 3.2, 2, 1.7 and 1.1%, respectively, for 0.01, 0.1, 5 and 20 ng V(V). Tolerance levels for forty foreign ions and cations are listed. A throughput of 40 samples/h was achieved. The method was applied to the analysis of V(V) in human serum, crude petroleum and river water with recoveries of 100-105%.
Vanadium Spectrophotometry

"Determination Of Cadmium, Cobalt, Copper, Manganese, Nickel, Lead And Zinc By Inductively Coupled Plasma Mass Spectroscopy Or Flame Atomic Absorption Spectrometry After Online Preconcentration And Solvent Extraction By Flow Injection System"
Microchem. J. 1996 Volume 54, Issue 4 Pages 402-411
A. Bortoli a, M. Gerottoa, M. Marchioria, F. Maricontib, M. Palontaa and A. Troncona

Abstract: A flow injection manifold and sequence of operations for online separation and pre-concentration of Cd, Co, Cu, Mn, Ni, Pb and Zn are diagramatically presented. Bonded silica with octadecyl functional group C18, packed in a microcolumn of 100 µL capacity, was used to collect diethyldithiocarbamate complexes of the heavy metals in aqueous solution. The metals were complexed with a chelating agent, adsorbed on the C18 column and eluted with methanol directly in the flow injection system. The metals were then determined by GF AAS or ICP-MS (details given). Calibration graphs and detection limits are presented.
Metals Cadmium Cobalt Copper Lead Manganese Nickel Zinc Spectrophotometry Mass spectrometry Sample preparation Spectrophotometry Preconcentration Solvent extraction C18 Chelation

"Optimization Of Flow Injection Online Microcolumn Preconcentration Of Ultratrace Elements In Environmental Samples Prior To Their Spectrochemical Determination"
Microchem. J. 1996 Volume 54, Issue 4 Pages 391-401
Zs. Horv&aacute;th, A. L&aacute;sztity, K. Zih-Per&eacute;nyi and &Aacute;. L&eacute;vai

Abstract: Multi-element pre-concentration of elements in water was performed by online flow injection on an iminodiacetic acid/ethyl cellulose (IDAEC) microcolumn. The eluent was 2 M HNO3 (2.5 ml/min). The pre-concentration of the elements was modelled in the presence of complexing agents such as citrate and oxalate at high Ca, Mg and sulfate concentrations. Elements were determined by ICP-MS or AAS. The effect of the species present in the solution was studied after construction of the species distribution curves using critical, estimated and measured stability constants. The stability constants of the IDAEC chelates were determined potentiometrically, and the constants were estimated using computer programs.
Trace elements Mass spectrometry Preconcentration Optimization Ultratrace

"Spectrophotometric Determination Of Palladium By Microwave FIA"
Anal. Lett. 1994 Volume 27, Issue 4 Pages 793-805
Xu, Y.J.;Hu, Z.D.

Abstract: In the cited FIA system (diagram given) samples (392.4 µL) and reagent [127.5 µL of 141 µM-2-(4-chloro-2-phosphonophenylazo)-7-(3-nitrophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid (chlorophosphonazo-mN)] were injected into a stream (1.78 ml/min) of 10 mM H2SO4 and carried to a reaction coil (10 m x 0.5 mm i.d.), 7 m of which was situated in a microwave oven operated for 30 s at 553 W. Formation of the blue complex was monitored at 615 nm (ε = 18 200); the sampling frequency was 20/h. Beer's law was obeyed from 2-10 µg/ml of Pd and the detection limit was 1 µg/ml; the RSD was 5.6% and the recovery was 95%.
Palladium Spectrophotometry Sample preparation Microwave Heated reaction

"Composition Of 'copper(II)-poly(3-methylthiophene) Conducting Polymer' Electrodes"
Anal. Lett. 1994 Volume 27, Issue 7 Pages 1225-1237
Xue, Z.L.;Karagzler, A.E.;Zimmer, H.;Amer, A.;Ataman, O.;Mark, H.B.

Abstract: The electrode material formed by the chemical polymerization of 3-methylthiophene using Cu(II) salts as catalysts had previously been reported to be a poly(3-methylthiophene) incorporating co-ordinately bound Cu(II). The Cu-based substance was used as a working electrode in an amperometric detector for the detection of inorganic anions in flow injection mode. Its commercial viability made it important to elucidate the composition. The Cu-based material was analyzed by FTIR, XPS, elemental analysis and cyclic voltammetry. The material was a composite of Cu(I) and Cu(II) cations with cyano- and hydroxo-groups and some lattice or co-ordinated water molecules.
Copper(I) Copper(II) Spectrophotometry Voltammetry Electrode Amperometry

"Application Of Differential Pulse Anodic-stripping Voltammetry With A Stopped-flow System For The Simultaneous Determination Of Lead, Copper, Antimony And Bismuth In Environmental Samples"
Anal. Lett. 1994 Volume 27, Issue 9 Pages 1779-1787
Wang, F.Q.;Li, S.Y.;Lui, S.D.;Zhang, Y.;Liu, Z.

Abstract: River water (250 ml) was mixed with 10 mL of HNO3 and evaporated to ~10 mL. Additional 10 mL portions of HNO3 and HCl were added, the solution was evaporated to near dryness and the residues dissolved in 25 mL of 1 M HCl. The solution was pumped at 1.5 ml/min for 40 s through a 100 µL flow cell containing a Ag/AgCl reference electrode and a dropping-Hg electrode maintained at -0.5 V. A stripping solution of 0.25 M malonic acid in 1 M HCl was pumped through at 1.5 ml/min for 20 s at the same potential. The flow was stopped and anodic voltammetry performed. Calibration graphs were linear for 1-1000 nM-Cu, Sb, Bi and Pb. At 1 µM-Cu, 0.5 µM-Sb and Bi and 0.48 µM-Pb RSD of better than 0.5% were obtained with recoveries of 100±7% at 10 nM for each metal. Using a deposition time of 5 min, a detection limit of ~8 nM was obtained. Mn(II), Se(IV), Te(IV) and As(III) at a 10-fold excess and Cd, Zn, Ni, Al, In(III), Ti(I), Co(II), and Fe(III) at a 50-fold excess did not interfere.
Lead Copper Antimony Bismuth Voltammetry Electrode Interferences Stopped-flow

"Continuous-flow Injection Reaction/stopped-flow Detection Using Derivative Spectrophotometry. Determination Of Cobalt And Iron In Mixtures"
Anal. Lett. 1996 Volume 29, Issue 6 Pages 1013-1025
Richter, P.;Toral, M.I.;Hernandez, P.

Abstract: A schematic diagram of the two-channel flow injection manifold is given. Sample was injected into a sodium acetate/acetic acid buffer of pH 5 (1.2 ml/min). The Fe in the sample was reduced in the first mixing coil (50 cm x 0.5 mm i.d.) before both analytes reacted with ferrozine in the second mixing coil (100 cm x 0.5 mm i.d.) at 2.4 ml/min. The Fe(II) and Co(II)-ferrozine complexes were then detected at 550 nm. When the signal reached the maximum height the flow was stopped and the absorption spectra were scanned from 400-700 nm with transformation to the first-derivative using a Δλ of 1.6 nm. Calibration ranges were 1.2-25 and 0.15-6 µg/ml of Co and Fe, respectively. The corresponding detection limits were 0.33 and 0.045 µg/ml. The method was applied to the determination of Co and Fe in water.
Cobalt Iron Spectrophotometry Spectroscopy Stopped-flow

"Flow Injection Analysis Of Chlorophenoxy Herbicides Using Photochemically Induced Fluorescence Detection"
Anal. Lett. 1996 Volume 29, Issue 8 Pages 1447-1461
Luisa F. Garcia; Sergei Eremin; Jean-Jacques Aaron

Abstract: Sample (300 µL) was injected into a water carrier stream and passed through a PTFE photoreactor (200 cm length) where it was irradiated for 90 s to 12 min via a low-pressure Hg lamp. Two modes of irradiation were utilized: (i) stopped-flow for all herbicides; and (ii) continuous-flow for 2-methyl-4-chlorophenoxyacetic acid, mecoprop and 4-(2-methyl-4-chlorophenoxy) butyric acid. The fluorescence of the resulting photoproducts was measured at 292 nm (excitation at 276 nm). Fluorescence intensity was increased by photolysis in a 50% methanol/pH 5 buffer solution. The sensitivity of the method was greater by the stopped-flow mode compared with the continuous-flow mode. Detection limits ranged from 23-98 ng/ml of chlorophenoxy herbicides. RSD were 0.7-2.7%. The method was applied to the determination of the herbicides in water; recoveries ranged from 96-108%.
Herbicides, chlorophenoxy Fluorescence Photochemistry Stopped-flow Buffer UV reactor

"Electrooxidation Of Ascorbic Acid At The Bis(4-pyridyl) Disulfide Modified Gold Electrode"
Electroanalysis 1994 Volume 6, Issue 2 Pages 119-123
Yuanwu Xie, Shaojun Dong

Abstract: A Au disc working electrode was modified by dipping the freshly polished electrode into 1 mM bis(4-pyridyl) disulfide for 2 min. The electrode was used for the study of the electro-oxidation of ascorbic acid using a Ag/AgCl (saturated KCl) reference electrode and a Pt wire counter electrode. The oxidation process was pH dependent due to the static interaction between ascorbic acid and the modified electrode surface. At 0.005-2 mM the peak currents show a good linear relationship with the concentrations of ascorbic acid. The modified electrode has greater stability and can be used in FIA.
Ascorbic acid Electrode Electrode Electrode

"Flow Injection Liposome Immunoanalysis (FILIA) With Electrochemical Detection"
Electroanalysis 1995 Volume 7, Issue 9 Pages 838-845
Alison J. Edwards *, Richard A. Durst

Abstract: Alachlor (I) in environmental samples was covalently bonded to dipalmitoyl phosphatidylethnolamine using N-succinimidyl-S-acetylthioacetate as described by Siebert et al. (Anal. Chim. Acta 1993, 282, 297). The I-bonded lipid was then dissolved in an organic solvent (not specified) and reacted with aqueous 100 mM potassium ferrocyanide of pH 7.4. After sonication and removal of the organic solvent, the liposome suspension was reacted with further potassium ferrocyanide (no details given) at 45°C, filtered, gel-filtered and dialysed. The dialysed liposomes were then diluted in PBS of pH 7.4 and 20 µL injected onto a column (5 cm x 4.3 mm i.d.) containing I-antibody-immobilized glass beads (preparation details given), PBS as mobile phase (0.55 ml/min) and amperometric detection at +330 mV vs. Ag/AgCl. Calibration graphs were linear for 1-10% liposomes bound on-column, with a detection limit of 0.5 ng I on-column.
Alachlor Amperometry Glass beads Immobilized antibody Liposomes

"Preconcentration By Flow Reversal In Conductometric Sequential Injection Analysis Of Ammonium"
Electroanalysis 1996 Volume 8, Issue 4 Pages 387-390
M. T. Oms, A. Cerd&agrave;, Victor Cerd&agrave; *

Abstract: A 75 µL portion of standard ammonium ion (I) solution and 100 µL 0.05 M NaOH were aspirated into a holding coil (150 cm x 1.5 mm i.d.) and transferred to the base compartment of a diffusion cell (construction described). The NH4+ ions were separated from the upper compartment which contained 0.05 M H3BO3 with a gas permeable membrane (0.22 µm pore) and NH3, which diffused through the latter, was absorbed in the H3BO3 and transferred to a 20 µL flow-through conductivity cell (described) with additional H3BO3 held in a coil (150 cm x 1.5 mm i.d.). Calibration graphs (relative conductivity) were linear up to 120 and 180 mg/l of I, respectively, with 0.05 M and 0.1 M H3BO3, respectively. The detection limit of 1.5 mg/l with an RSD of 3%, was reduced to 0.1 mg/l with pre-concentration achieved by five successive sample flow reversals (discussed), but the linear range was reduced to 80 mg/l. The procedure was applied successfully to the analysis of ammonium ions in waste waters.
Ammonium Conductometry Sequential injection Preconcentration

"A Serial Array Of ISE For Use In A Portable Battery-powered Flow Injection Analyser"
Electroanalysis 1996 Volume 8, Issue 5 Pages 438-442
Telis Dimitrakopoulos, Peter W. Alexander *, D. Brynn Hibbert

Abstract: Natural water samples (200 µL) were injected into a carrier stream of either 50 mM MgSO4, 1 mM CaCl2 or 7 mM lithium acetate (6.8 ml/min) of a flow injection potentiometric system and the K, Na and nitrate ions were simultaneously detected using a planar ISE serial array (schematic shown; details given). Calibration data of the respective standard ion solutions treated with 1 mM CaCl2, and analytical data of the studied ions in the three carrier solutions are presented and discussed. The method was applied to the analysis of two natural mineral water samples (details given). Results were in good agreement with those obtained by the standard AAS method.
Nitrate Potassium Sodium Electrode Electrode Electrode Potentiometry Portable Method comparison

"Torulopsis Candida-based Sensor For The Estimation Of Biochemical Oxygen Demand And Its Evaluation"
Electroanalysis 1996 Volume 8, Issue 7 Pages 698-701
S. Sangeetha, G. Sugandhi, M. Murugesan, V. Murali Madhav, Sheela Berchmans, R. Rajasekar, Sumathi Rajasekar, D. Jeyakumar, G. Prabhakar Rao *

Abstract: The cited micro-organism was grown in a broth and harvested by centrifugation. The isolated microbes were dispersed in phosphate buffer of pH 7 and immobilized on a cellulose nitrate membrane by adsorption on to the pores, which was effected by filtration of a 0.5 mL portion of the dispersion through the membrane under reduced pressure. The prepared membrane was coupled to a dissolved O2 sensor by means of dialysis membrane kept in position with an O-ring. The sensor was used in a FIA system with phosphate buffer as the carrier stream (25 ml/h). Amperometric measurements were made at an applied potential of -0.6 V vs. Ag/AgCl. Calibration graphs were constructed with standard solutions of glucose/glutamic acid, and were linear up to 500 mg/l, corresponding to a BOD value of 370 ppm. The sensor, which is intended for application to effluents, exhibited good stability and a fast response time.
Oxygen, biochemical Sensor Dialysis

"Methods Of Analysis Of Polar Aromatic Sulfonates From Aquatic Environments"
J. Chromatogr. A 1996 Volume 733, Issue 1-2 Pages 473-489
Thorsten Reemtsma

Abstract: Methods for the analysis of aromatic sulfonates, such as linear alkylbenzene sulfonates (LAS) and (amino- and hydroxy-substituted) benzene and naphthalene sulfonates, from aqueous media are reviewed. All analytical steps including the extraction from water, clean-up from co-extracted substances, chromatographic separation and detection, and methods of identification of these compound classes are described and discussed. The techniques employed are solid-phase extraction, various modes of high performance liquid chromatography (HPLC), capillary electrophoresis, gas chromatography (GC), GC-mass spectrometry, liquid chromatography-mass spectrometry, continuous-flow- and flow injection mass spectrometry, and spectroscopic methods. A remarkable gap becomes obvious between novel analytical methods developed with standard mixtures and those methods readily employable for environmental analysis. Finally, suggestions for future analytical developments are given.
Sulfonamides HPLC Mass spectrometry Review

"Bioseparation And Bioanalytical Techniques In Environmental Monitoring"
J. Chromatogr. B 1998 Volume 715, Issue 1 Pages 211-228
J. M. Van Emon*, C. L. Gerlach and K. Bowman

Abstract: The growing use of antibody-based separation methods has paralleled the expansion of immunochemical detection methods in moving beyond the clinical diagnostic field to applications in environmental monitoring. In recent years high-performance immunoaffinity chromatography, which began as a separation technique in biochemical and clinical research, has been adapted for separating and quantifying environmental pollutants. Bioaffinity offers a selective biological basis for separation that can be incorporated into a modular analytical process for more efficient environmental analysis. The use of immunoaffinity chromatography for separation complements the use of immunoassay for detection. A widely used immunochemical detection method for environmental analyzes is enzyme immunoassay. The objective of this paper is to review the status of bioaffinity-based analytical procedures for environmental applications and human exposure assessment studies. Environmental methods based on bioaffinity range from mature immunoassays to emerging techniques such as immunosensors and immunoaffinity chromatography procedures for small molecules.
Immunoassay LC Review

"New Spectroelectrochemical Cell For Flow Injection Analysis And Its Application To The Determination Of Iron(II) Down To The Femtomole Level By Surface-enhanced Resonance Raman Scattering (SERRS)"
J. Electroanal. Chem. 1994 Volume 371, Issue 1-2 Pages 37-42
Vitor J. P. Gouveia, Ivano G. Gutz and Joel C. Rubim*

Abstract: A principal feature of the cell (diagrams presented) is the in situ renewal of the surface-enhanced Raman-active Ag substratum. Before injection of the analyte, Ag+ are introduced, and Ag is electro-deposited on a vitreous-carbon electrode; after the Raman spectrum of the adsorbed analyte has been recorded, the Ag is removed by anodic stripping. Fe(II) was determined in a 130 µL injected sample as its tris(bipyridyl) complex, which exhibits both a resonance Raman effect when excited with Ar+ laser 514.5 nm radiation and surface-enhanced Raman scattering when adsorbed on Ag. The calibration graph was sigmoidal, but usable for 10 nM-10 µM-Fe(II), and the detection limit was 1 nM, which represented detection of Fe(II) at the femtomole level.
Iron(2+) Electrode Raman

"A Microbioreactor Based On Interfacial Polymerisation And Application To Flow Injection Analysis Of Glucose"
Sens. Actuat. B 1996 Volume 34, Issue 1-3 Pages 422-428
Muntak Son, Frank Peddie*, Dennis Mulcahy, David Davey and Malcolm R. Haskard

Abstract: A bioreactor chamber was created by anisotropic etching of a Si wafer. The chamber was attached to a microelectronic sensor using epoxy resin. A biocatalyst, e.g., an enzyme, a combination of enzymes or intact viable cells, could then be contained within the chamber by an ultra-thin nylon membrane (preparation details given). The membrane was tightly sealed to the Si wafer surface by pretreating the wafer with a silylating reagent by dipping into dry toluene containing 10% γ-aminopropyl triethoxysilane and refluxing for 24 h. The membrane was then created by interfacial polymerization. The nylon membrane could then be covalently linked to the wafer surface by appropriate selection of aqueous and organic phase constituents. The microbioreactor was successfully used as a glucose sensor within a flow injection cell; results indicate that many other applications are feasible.
Glucose Sensor Nylon

"Flow Injection Method For The Rapid Determination Of Chemical Oxygen Demand Based On Microwave Digestion And Chromium Speciation In Flame Atomic Absorption Spectrometry"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1791-1800
A. Cuesta, J. L. Todoli* and A Canals

Abstract: In the manifold illustrated, the water sample is mixed with a K2Cr2O7/H2SO4/ HgSO4/Ag2SO4 reagent prep. described and a 10^-240 µL portion is injected into a stream of water, which carries it through a microwave oven. The residual Cr(VI) is retained on an anion-exchange resin column and subsequently eluted for determination by flame AAS. COD values of 25-5000 mg/l can be measured, and the detection limit is ~7 mg/l. Fifty determinations can be performed per h. There is no matrix effect.
Chemical oxygen demand Spectrophotometry Microwave Speciation Interferences Online digestion

"Flow Injection Sorbent Extraction With Dialkyl Dithiophosphates As Chelating Agent For The Determination Of Cadmium, Copper And Lead By Flame Atomic Absorption Spectrometry"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1917-1923
Renli Ma and Freddy Adams*

Abstract: Of the OO-dialkyl phosphorodithioates evaluated for retention of the cited heavy metals on a Perkin-Elmer B050-4047 C18 column containing 20 mg of ODS silica gel (cf. Anal. Chim. Acta, 1994, 285, 33), the best was diethyl phosphorodithioate in the presence of 0.1 M citrate at pH 3 (buffered with ammonium acetate). With loading for 20 s at 8.7 ml/min the enhancement factors for the cited metals were 35, 35 and 26 and the detection limits were 0.8, 1.4 and 10 µg/l, respectively. The method is applicable to digests of environmental, biological and industrial materials.
Cadmium Copper Lead Sample preparation Spectrophotometry Sample preparation Chelation Solid phase extraction C18 Silica gel

"Determination Of Arsenic, Antimony, Bismuth And Mercury In Water Samples By Flow Injection Inductively Coupled Plasma Mass Spectrometry With An In Situ Nebulizer/hydride Generator"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1813-1821
Chih-Shyue Chen and Shiuh-Jen Jiang*

Abstract: The sample (0.2 mL) is injected into a stream (1 mL/min) of 0.5% cysteine solution in 0.05 M HNO3 that then merges with a stream (1 mL/min) of 0.2% NaBH4 solution in 0.02 M NaOH. The combined streams then pass to a crossflow pneumatic nebulizer with a Scott-type spray chamber for introduction into the ICP of an ELAN 5000 ICP-MS instrument; at the instrument settings tabulated, one data point could be recorded per s. Either the height or area of the flow injection peak could be used as the signal; calibration graphs based on peak heights were linear for 0.1-10 ng/mL of the cited elements, and the detection limits were 3, 17, 3 and 170 pg/mL, respectively. Both direct calibration and the method of standard additions gave satisfactory results for tap water, but for river and seawater use of the method of standard additions was necessary; for seawater it was also necessary to correct for the interference from 40Ar35Cl+ with the determination of 75As+ (equation given).
Antimony Arsenic Bismuth Mercury Mass spectrometry Interferences Standard additions calibration Volatile generation Volatile generation

"Analytical Characteristics Of A High Efficiency Ion Transmission Interface (S Mode) Inductively Coupled Plasma Mass Spectrometer For Trace Element Determinations In Geological And Environmental Materials"
Spectrochim. Acta B 1998 Volume 53, Issue 6-8 Pages 1087-1107
I. B. Brenner*, M. Liezers, J. Godfrey, S. Nelms and J. Cantle

Abstract: The analytical performance of a high transmission interface (S mode), inductively coupled plasma-quadrupole mass spectrometer (the VGE Plasma Quad 3) was evaluated for multitrace element analysis of geological and environmental materials. The sensitivity, limits of detection (LODs), effect of Ca and Na and other major elements on mass response, background, percentage 156CeO+/140Ce+, 70Ce++/140Ce+, and long- and short-term variations were compared with those obtained with the conventional mode (normal mode). Normal mode sensitivities varied from 20 MCPS ppm-1 (millions of counts per s per ppm) for 9Be+, 70-80 MCPS ppm-1 for 59Co+, 90 for 115In+ and 40-50 MCPS ppm-1 for the heavy masses. S mode sensitivities were 180 MCPS ppm-1 for 59Co+, 350-380 for 115In+ and 140Ce+, 300 MCPS ppm-1 for 208Pb+, and 150 MCPS ppm-1 for 232Th+ and 238U+, i.e. enhancements amounting to 7. Three s normal and S mode LODs are mainly in the 1-2 and 0.1 ppt range, respectively. S mode LODs are enhanced relative to the normal mode, for masses >80 amu, by factors ranging from ~10 to 50. S mode LODs are depressed relative to normal mode LODs for masses <50 amu by a factor of 10, and the extent of depression is related linearly to mass. In the high- and mid-mass ranges, backgrounds were ~10. They were not affected by sample composition: at 8 amu the S mode background for real samples amounted to ~20, whereas at 220 amu it amounted to four counts. S and normal mode percentage 156CeO+/140Ce++ and percentage Ce++/Ce+ ratios were ~1.5%, and temporal variations were insignificant. The percentage RSDs of normal and S mode Sr+, Ag+ and Pb+ isotope ratios were ~0.1%, with the exception of S mode 208Pb+ and 208Pb+/206Pb+ ratios in the presence of NaCl, which were degraded by a factor of ~2. Normal and S mode long-term variations for continuous aspiration of 0.1% NaCl for periods of up to 13 h were mass dependent, varying from 2.5-4% for 7Li+ and 9Be+ to ~2% for the mid-mass range, increasing slightly to ~3% for high masses. Most of this variation occurred during the 1st 100-150 min of the anal. during cone priming. With compensation, normal and S mode long-term percentage RSDs and drift were reduced to 1-2%. These variations indicate that extended periods of S mode anal. can be conducted without periodic recalibration. A calibration procedure, based on spiked HNO3, was validated by analyzing spiked NaCl solutions, standard water and geological standard reference material (SRM) solutions with internal standardization using conventional solution delivery and flow injection. The agreement of the S mode data and the certified and literature values for ultratrace elements, including ppt levels of rare earth elements in the water standards, was satisfactory. An important conclusion is that ion sampling effects in the S mode are minimal and that the enhanced ion transmission interface is not only beneficial for microanalysis using laser ablation, but for geological and environmental type solutions as well. Sensitivity enhancements were preserved and matrix effects were approximately ±20% for solutions containing 0.1-0.2% total dissolved salt concentration. These variations were reduced to <5% with internal standards matched in mass and ionization potential.
Metals, rare earth Mass spectrometry Interface Reference material Apparatus

"Development Of A Novel Detector For Flow Injection Analysis Based On Optical Beam Deflection Induced By The Reaction Heat"
Anal. Sci. 1994 Volume 10, Issue 1 Pages 203-205
X.-Z. WU, H. SHINDOH, M. YAMADA, E. KOBAYASHI and T. HOBO

Abstract: A flow reaction cell is described in which the lower part contained CCl4 and an aqueous HCl solution was passed above the organic phase. A probe beam produced by a He-Ne laser of wavelength 632.8 nm was passed through the CCl4 phase at a distance of 1 mm from its interface with water, and the deflection of the beam was measured by a knife-edge and photodiode system. The 2.5 cm high, 2 mm wide cell was constructed from silanized glass sheets. As a model reaction, aqueous NaOH was injected into the HCl flow line at 0.5 ml/min, and the neutralization heat was transferred to the CCl4 phase, generating a temperature gradient. This induced a RI gradient which in turn generated a deflection in the probe beam. The deflection signal was proportional to the concentration of NaOH from 0.05-0.5 M for 100 µL injected, and the detection limit was 0.05 M NaOH or 5 µmol.
Sodium hydroxide Spectrophotometry Photodiode

"Utilization Of Flow Injection Analysis In Agrochemical Laboratories"
Agrochemia 1987 Volume 27, Issue 9 Pages 273-276
Karlicek, R.;Dolejsova, J.

Abstract: NA
Review

"Flow Injection Analysis As A Tool For Metal Speciation"
Am. Lab. 1984 Volume 16, Issue 7 Pages 17-18
Pacey, G.E.;Bubnis, B.P.

Abstract: The usefulness of flow injection analysis in automated systems (with pump programming and 'packed-bed' reaction coils) is described for the rapid processing of large numbers of samples. The importance of metal speciation in environmental and toxicological studies is emphasized and, as an example, a flow injection method for determination of Fe(II) and Fe(III) with use of 1,10-phenanthroline and spectrophotometry at 512 nm is described; it was suitable for application in the range 5 to 30 ppm of each species.
Iron(2+) Iron(III) Spectrophotometry Spectrophotometry Pump programming Speciation Review

"Liposome Immunoanalysis For The Environment"
Anal. Eur. 1996 Volume 45, Issue 1 Pages 48-50
Durst, R.A.;Reeves, S.G.

Abstract: The use of liposomes in immunoassays to provide encapsulated markers as signal enhancers is presented. The liposomes are spherical bi-layer vesicles that can entrap a water-soluble marker during their formation. The markers can be visible dyes, fluorescent dyes, chemi/bioluminescent substrates, electroactive species or enzymes. The liposome surface contains an analyte tag which binds to a cell surface antibody, the marker is then measured directly (visible dyes) or the liposome is lysed before measurement can be performed. The liposomes can be used in an enzyme-linked flow injection liposome immunoanalysis (FILIA) and a system for the detection of alachlor is outlined. The system used an immunoaffinity column containing immobilized antibodies and had a detection limit of 5 ppb alachlor. The liposome markers can also be mixed with sample and applied to plastic-backed nitrocellulose containing an antibody competition zone and a liposome capture zone to produce test strips, the color of the liposome capture zone being measured. The use of test strips for multi-analyte assays is discussed.
Liposome Immunoassay Liposomes

"Automated Optical Sensing System For Biochemical Assays: A Challenge For ELISA?"
Anal. Methods Instrum. 1993 Volume 1, Issue 1 Pages 43-51
Oroszlan, P.;Thommen, C.;Wehrli, M.;Duveneck, G.;Ehrat, M.

Abstract: The FOBIA (fiber-optic biospecific interaction analysis) system, based on FIA combined with evanescent-wave optical-fiber fluoroimmunosensor technology, is described, which can be used in both competitive and sandwich assays. The immunosensor can be regenerated 350 times, the cycle time is 15 to 30 min, and the the coefficient of variation of the signal is 1 to 5%. It is inferior to ELISA in parallel analyzes, but gives better results in a shorter time. Applications in both the clinical and environmental fields are described.
Fluorescence Immunoassay Clinical analysis Optical fiber

"Colorimetric Determination Of Available Iron In Soils By Flow Injection Analysis"
Analusis 1996 Volume 24, Issue 8 Pages 343-346
AMR Ferreira, JLFC Lima, AOSS Rangel

Abstract: A method is presented based on formation of the Fe(II)-1,10-phenanthroline complex in aqueous solution. A large injection volume was used to eliminate RI interferences. Soil was extracted with ammonium acetate using a standard method then 540 µL was injected into a stream of 1 ml/min water in a FIA system constructed from PTFE tubing (0.8 mm i.d.) and acrylic Y-shaped joints. After mixing with 0.01% ascorbic acid at a flow rate of 1 ml/min in 1.2 M HCl in a 15 cm coil, the stream was mixed at a flow rate of 2 ml/min with 0.01% 1,10-phenanthroline in 1.5 M sodium acetate in a 200 cm coil. Absorbance was measured at 508 nm at the central plateau in the detector signal. The detection limit was 0.07 mg/l Fe. RSD were 0.82-1.72% (n = 10) for 1.55-5.14 mg/l Fe. The method could be applied to 60 samples/h; when applied to 20 samples, results agreed with those of a standard reference method.
Iron Spectrophotometry Interferences Standard method Method comparison

"Effect Of Arsenous And Arsenic Acids On The Chemiluminescence Of Luminol In The Absence Of Hydrogen Peroxide And Its Analytical Application"
Bull. Chem. Soc. Jpn. 1994 Volume 67, Issue 8 Pages 2317-2319
Hiroyuki Sakai, Terufumi Fujiwara and Takahiro Kumamaru

Abstract: A FIA system is proposed for the determination of As(III) and As(V) based on a previously described system (Cf. Ibid., 1993, 66, 3401). Sample was injected into a flow stream of 0.75 mM HClO4 of pH 3.2 which passed into a cation-exchange column (20 cm x 4.9 mm i.d.) of SCX-1. The eluate was mixed with a reagent stream of 0.8 mM luminol in 3 mM KOH of pH 11.1 in a coiled flow cell. The chemiluminescence was measured. Calibration graphs were linear for 0.5-15 µg/ml of As(III) and As(V) with detection limits of 100 ng/ml. RSD (n = 5) were 6.1 and 6.9% for 3 µg/ml of As(III) and As(V), respectively. The method was applied to the determination of As in environmental certified reference samples.
Arsenic Chemiluminescence Ion exchange Reference material Column Resin

"Semi-automatic Hydride Generation And Atomic Absorption Determination Of Bismuth With Insitu Concentration In A Graphite Furnace"
Bull. Korean Chem. Soc. 1991 Volume 12, Issue 3 Pages 290-295
Yong-Keun Lee*, Dong Soo Lee, Byung Mok Yoon, and Hoon Hwang

Abstract: A semi-automatic method for the determination of dissolved bismuth at parts per trillion levels is described. The method involves bismuthine generation, in situ collection of bismuthine in a graphite furnace, and atomic absorption detection. In order to facilitate semi-automation of bismuthine generation and separation from aqueous solution, Gore-tex microporous PTEE membrane is used. The absolute detection limit, taken as three times the standard deviation of the instrument noise is 2 pg. The precisions are 3.1% for 100 pg and 1.9% for 1 ng of bismuth, respectively. As many as 90 measurements can be made in an hour.
Bismuth Spectrophotometry Interferences Volatile generation Volatile generation

"Apparatus For Measuring Chemical Oxygen Demand Based On Flow Injection Analysis"
Bunseki Kagaku 1980 Volume 29, Issue 3 Pages 222-223
KORENAGA Takashi

Abstract: A simple apparatus was developed for the rapid and continuous determination of chemical oxygen demand (COD) in environmental water samples based on the principle of flow injection-spectrophotometric analysis. A solution of 2.7 x 10^-4 M potassium permanganate in 3.3% sulfuric acid was pumped with a reciprocating pump into the manifold to which 20µl of sample (i.e. sodium oxalate solution) was also introduced by manual injection. After reaction, the mixture went through a quartz flow cell (10 mm light path, 18 µL volume) placed in a spectrophotometer operated at a wavelength of 525 nm. The manifold was made entirely of polytetrafluoroethylene tubing (0.5 mm inner diameter, 10 m length). The signal from the spectrophotometer was continuously recorded. When a pumping rate was chosen to be 1.9 mL min^-1 a residence time was 1 min. A sampling rate of 120 samples per hour was achieved and the apparent COD at a concentration range of 21-170 mg COD L^-1 was measured reproducibly. Chloride at 10 mg L-l level was suppressed by adding 0.1% silver nitrate in the flow injection system.
Chemical oxygen demand Spectrophotometry Apparatus

"Investigation Of Collecting Conditions For Determination Of Arsine In Working Environment Of Semi-conductor Manufacturing Process"
Bunseki Kagaku 1991 Volume 40, Issue 3 Pages 149-152
Koyama, M.;Chaki, S.;Yamamoto, M.;Kumamaru, T.

Abstract: Sample gas (3 l) was passed at 1 l min-1 for 30 min through an impinger, comprising a bent-type gas dispersion tube sintered with a porous glass plate (20 mm i.d.; 40 to 100 µm), containing 20 mL of 2% KMnO4 - 0.6% H2SO4 solution The absorbing solution was treated with 10 mL of 2.5% H2O2 - 0.6% H2SO4 solution and As was determined by flow injection analysis - hydride-generation AAS. Arsine was determined in the working environment from 8.7 to 420 µg m-3. Recovery was 95%.
Arsine Sample preparation Spectrophotometry

"Preconcentration Or Analysis Of Trace Ionic Compounds In The Environment"
Bunseki Kagaku 1994 Volume 43, Issue 9 Pages 727-728
Kobayashi, J.

Abstract: Al3+ at parts-per-1012 to ppb levels was concentrated on a column of 2-(salicylideneamino)thiophenol (immobilized on glass beads), eluted with HNO3, and determined online by flow injection spectrophotometry with catechol violet or offline by AAS. Cu2+ at the same levels was concentrated on a column of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthrolinedisulfonic acid (I) (immobilized on glass beads), eluted with HNO3 and determined online by flow injection spectrophotometry with I. Inorganic anions and carboxy-anions at these levels were concentrated on an anion-exchange column, eluted with toluene-p-sulfonic acid and determined online by ion chromatography with spectrophotometric detection.
Aluminum(III) Copper(II) Anions Spectrophotometry HPLC Spectrophotometry Preconcentration Glass beads

"Theoretical Studies Of Flow Injection Analysis And Application For Monitoring Water Quality At Power Plants With A Newly Developed Flow Injection Analyser"
Bunseki Kagaku 1996 Volume 45, Issue 1 Pages 107-108
Li, Y.S.

Abstract: The development is described briefly of the FIA-T1-721 analyzer., which is capable of a pump speed of 7.5-150 (±0.5) rpm and shows RSD of 0.5% and a drift of 0.002 absorbance units per h.

"Potentiometric Flow Injection Determination Of Trace Hydrazine And Its Application To Boiler Water"
Bunseki Kagaku 1996 Volume 45, Issue 7 Pages 689-695
Ohura, H.;Imato, T.;Yamasaki, S.

Abstract: The sample (0.2 ml) is injected into a carrier stream of water (1 ml/min) that then merges with a stream (1 ml/min) of 0.2 mM Ce(IV)/0.2 mM Ce(III) in 1 M H2SO4, and after passage of the merged streams through a PTFE reaction coil (0.2 m x 0.5 mm i.d.) the potential of a flow-through Pt electrode is measured vs. an Ag/AgCl reference electrode. The peak height varies linearly for 0.5-5 µM-hydrazine, and the detection limit is 0.1 µM. The RSD (n = 6) for 5 µM-hydrazine was 0.9%. By altering the concentration of the Ce(IV) and Ce(III) from 0.1-10 mM the method can be applied to 0.1 µM-1 mM hydrazine. The sampling rate is 40 per h. Good recovery was obtained of 10 ppb of hydrazine from boiler water.
Hydrazine Potentiometry

"Flow Injection Spectrophotometric Determination Of Trace Amounts Of Hydrazine In Boiler-feed Water"
Bunseki Kagaku 1996 Volume 45, Issue 11 Pages 993-998
Tsuboi, T.;Nakamura, T.;Matsukura, A.;Motomizu, S.

Abstract: A 0.3 mL sample was injected into a carrier stream (1 ml/min) of water, which then merged with a stream (0.6 ml/min) of 1.8% 4-dimethylaminobenzaldehyde solution in 4.5% HCl and passed through a reaction coil (6 m x 0.5 mm i.d.) at 80°C and then through a cooling coil (1 m x 0.5 mm i.d.). The absorbance was measured at 458 nm. The calibration graph was linear up to 100 ppb of hydrazine and the detection limit was 0.2 ppb. The RSD (n = 7) at 5, 50 and 100 ppb of hydrazine were 1.1, 0.9 and 0.4%, respectively.
Hydrazine Spectrophotometry

"Development Of Novel Redox Systems In Potentiometry And Its Application To Analytical Chemistry"
Bunseki Kagaku 1996 Volume 45, Issue 12 Pages 1151-1152
Teshima, N.

Abstract: A brief account is given of analytical applications arising from the modification of the redox potential of a metal/metal-ion system by complexation of the ions with a ligand. Thus, V(IV) can be titrated potentiometrically with Fe(III), and Co(II) with V(V) or Cr(VI), in the presence of 1,10-phenanthroline or 2,2'-bipyridyl. Flow injection spectrophotometric procedures based on this principle are also mentioned. These are applicable to determination of the ligands as well as the metals; a method for measuring the complexing capacity of natural water was developed on this basis.
Potentiometry Spectrophotometry Redox

"Recent Developments In Speciation Analysis Of Selenium"
Chem. Anal. 1995 Volume 40, Issue 5 Pages 677-686
Pyrzynska, K.

Abstract: The review concerns the specific problems of selenium speciation analysis. The distribution of the element, sample storage, its decomposition prior to analysis as well as the pre-concentration and separation techniques is discussed. Recent developments in the determination of inorganic and organic selenium compounds are presented. (124 references)
Selenium Selenium, organic Spectrophotometry Mass spectrometry Spectrophotometry GC Review Speciation Preconcentration

"Flame Atomic Absorption Spectrophotometry Coupled With Solvent Extraction/flow Injection Analysis"
Chem. Pharm. Bull. 1983 Volume 31, Issue 4 Pages 1419-1421
Ogata, K.;Tanabe, S.;Imanari, T.

Abstract: The method was developed for determining Zn in 200 µL volume of solution derived from biological or environmental samples; its adaptation to other trace elements is suggested. The technique is based on direct connection of the AAS instrument to the solvent extraction - flow injection system with an 'air compensation' technique (cf. Nord and Karlberg, Anal. Abstr., 1981, 41, 5J85, and Yoza et al., Anal. Chim. Acta, 1979, 111, 163). The detection limit was 10 ppb with a throughput of 60 samples per hour. The calibration graph was rectilinear for 20 to 800 ppb of Zn.
Zinc Spectrophotometry Sample preparation Phase separator Solvent extraction

"Environmental Immunoassays And Other Bioanalytical Methods: Overview And Update"
Chemosphere 1997 Volume 34, Issue 5-7 Pages 1011-1025
James Sherry

Abstract: Immunoassays and bioanalytical techniques can aid the cost effective detection and quantification of trace contaminants in the environment, food, and human and animal populations. This overview of recent progress shows that rapid advances have occurred in the development and validation, of assays for many contaminants of both industrial and agricultural origin. Promising antibody based techniques such as immunoaffinity chromatography, biosensors, and flow injection immunoanalysis continue to evolve. Such techniques can not only help lower costs and improve efficiency, but can also allow the range of hypotheses that can be tested in many environmental studies to be broadened by permitting the determination of trace residues in small volume samples that would be otherwise difficult to analyze.
Biochemical analysis Immunoassay Sensor Review

"Ion-selective Electrode And Enzyme Sensors For Flow-type Environmental Analysis"
Collect. Czech. Chem. Commun. 1991 Volume 56, Issue 1 Pages 178-191
Thomas, J.D.R.

Abstract: A review is presented, with 27 references
Electrode Sensor Enzyme

"Use Of Dialysis To Limit Interferences In The Turbidimetric Determination Of Sulfate"
Commun. Soil Sci. Plant Anal. 1996 Volume 27, Issue 9-10 Pages 2159-2169
Menzies, N.W.;Kameni, R.

Abstract: Soil (2 g) was shaken for 2 days with 20 mL 1.5 mM CaCl2/0.5 mM CaSO4, and subsequently centrifuged at 1000 g. The extracts were dialysed and analyzed by continuous-flow turbidimetry using BaCl2 reagent and detection at 420 nm (details given). The effects of particulates and organic matter on the determination of sulfate were assessed using filtration (0.025 µm) and H2O2 digestion (no details given). The dialysed solutions were additionally analyzed on a Waters IC Pac A anion-exchange column (dimensions not given) equipped with a 300 mg Alltech C18 guard column (dimensions not given), aqueous 1.5 mM sodium gluconate/5.8 mM boric acid/1.3 mM sodium borate/acetonitrile/glycerol as mobile phase (1.2 ml/min) and conductivity detection. Total S and organic C in the dialysed solutions were determined by ICP-AES at 182 and 193.1 nm respectively. Turbidimetric calibration graphs were linear from 0.1-2 mM sulfate, with quantitative recovery (no data presented). The turbidimetric results were comparable to those obtained by ion chromatography.
Sulfate Turbidimetry Spectrophotometry Sample preparation Dialysis Interferences

"Environmental Chemistry: The Immunoassay Option"
Crit. Rev. Anal. Chem. 1992 Volume 23, Issue 4 Pages 217-300
J. P. Sherry; Raymond E. Clement

Abstract: A review is presented, with 392 references, on immunoassay screening techniques for the detection of a broad variety of environmental pollutants, including, pesticides, PCB and other industrial contaminants. Sample preparation, validation and routine applications, and the future prospects of the technique are discussed. Ways to increase assay sensitivity are also described. Related technologies, including immunoaffinity chromatography, immunosensor probes and flow injection immunoanalysis, and multi-analyte immunoassays are also reviewed.
Immunoassay Review

"Biosensors And Flow Injection Analysis"
Curr. Opin. Biotechnol. 1992 Volume 3, Issue 1 Pages 31-39
Chien-Yuan Chen and Isao Karube

Abstract: A review is presented, with 56 references. Applications of the technique, viz. diagnostic analysis, analysis of food and agricultural products, environmental analysis, are discussed. Combining flow injection analysis with a biosensor is a novel biosensing process which has allowed speedy and accurate analysis. Diagnostic analysis is the most important application for biosensing flow injection analysis, but other applications include bioprocess monitoring, analysis of food and agricultural products, as well as environmental analysis. In addition, the analysis of compounds, such as explosives and abused drugs, and monitoring of Salmonella, the microorganism that causes food poisoning, have been reported.
Sensor Review Process monitoring

"Flow Injection Analysis - New Environmentally Safe Analytical System For Future Laboratories"
Dan. Kemi 1983 Volume 64, Issue 1 Pages 4-8
Hallas, M.

Abstract: The rapid development of the technique (due to its ease of automation, flexibility, reproducible analysis times, economy and non-polluting characteristics) is reviewed. Examples of its application for large numbers of routine samples are given. (22 references).
Review

"Reflectometric Interference Spectroscopy For The Determination Of Atrazine In Natural Water Samples"
Environ. Sci. Technol. 1996 Volume 30, Issue 6 Pages 1846-1851
C. Mouvet, L. Amalric, S. Broussard, G. Lang, A. Brecht, and G. Gauglitz

Abstract: A reflectometric interference spectroscopy (RIFS; reflectance interferometry) system consisting of a halogen lamp, a flow cell and a diode array detector is described; diagram given. Water containing atrazine was mixed with PBS and K4E7 atrazine mAb and incubated for 5 min. The solution was injected into a FIA system which delivered the sample to the flow cell of the RIFS system for measurement of the optical thickness of a thin transparent film. The unoccupied antibodies bind to a atrazine modified transducer surface increasing the optical thickness; the lower the atrazine content the larger the number of unoccupied antibodies. The calibration graph was produced for 0.1-5 µg/l of atrazine with a detection limit of 0.35 µg/l. There was significant cross-reactivity from simazine and terbutylazine and humic acids interfered with the determination.
Atrazine Spectroscopy Interferences Detector Flowcell

"Ion-selective Electrode-flow Injection Analysis"
Fenxi Huaxue 1986 Volume 14, Issue 5 Pages 387-390
Han, W.;Fan, L.

Abstract: The effects of sample volume, tube length and diameter, peak height and sampling rate on the determination of NH3, F- and Ca were investigated. Optimum conditions of 0.35 mL sample volume in a tube (50 cm x 1 mm) at a flow rate of 5.6 mL min-1 (for 60 samples h-1) were obtained with electrolytes of 1 M NaOH (for NH3), 0.5 M Na citrate (for F-) and 0.2 M NaCl (for Ca) in the carrier stream. The coefficient of variation were <1.7%. Calibration graphs were rectilinear from 0.1 to 10 mM for NH3, F- and Ca with responses of 51, 59 and 30 mV per decade, respectively. The method could be applied to samples of agricultural, pharmaceutical, clinical and environmental materials.
Ammonia Fluoride Calcium Clinical analysis Electrode Electrode Electrode Optimization Theory

"Determination Of Trace Amounts Of Selenium In Environmental Samples By Hydride-generation Atomic Absorption Spectrometry Combined With Flow Injection Analysis"
Fenxi Huaxue 1986 Volume 14, Issue 10 Pages 738-743
Wang, X.;Fang, Z.L.

Abstract: Selenium in environmental materials was determined by the cited technique with a detection limit of 0.06 ng mL-1 and a coefficient of variation of 1.6% at 4 ng mL-1 of Se. The sampling frequency was 250 to 300 h-1 with use of 0.4 mL injections. Results obtained with use of NBS Standard Reference Materials were in good agreement with certified values. Interference was not as high as in other methods. Sample pre-treatment methods are given.
Selenium Spectrophotometry Interferences Reference material

"Flow Injection Preconcentration For The Determination Of Phenol"
Fenxi Huaxue 1996 Volume 24, Issue 3 Pages 312-314
Li, J.F.;Zhang, F.J.;Dang, Z.M.;Tang, Z.X.

Abstract: Portions of standard phenol (I) solution at 40°C, adjusted to pH 8, were injected at 4.2 ml/min into a carrier stream of a flow system (schematic shown) and carried to a VS-II cation-exchange fiber column for online pre-concentration. I was eluted with a stream of 0.8 M NaCl of pH 7 at 5.1 ml/min and mixed with a stream of chromogenic reagent of 4-aminoantipyrine (7 g/l) at 2.3 ml/min in a reaction tube (10 cm long) followed by an oxidant stream of potassium ferricyanide (40 g/l) at 2.6 ml/min in a reaction coil (48 cm). The absorbance of the colored product formed was measured at 510 nm. The calibration graph was linear from 0.01-1.4 mg/l of I. Sampling frequency was 90 runs/h. The method was applied to the analysis of polluted lake water, with RSD of 0.23%. Results were compared with those obtained by the classical method.
Phenols Spectrophotometry Preconcentration Chromogenic reagent

"Determination Of Aniline In Water By Flow Injection Analysis With Membrane Separation"
Fenxi Huaxue 1996 Volume 24, Issue 5 Pages 603-605
Xu, H.H.;Chen, J.H.;Zhu, M.;Zhang, J.

Abstract: A flow injection system (schematic shown), containing a silicone-rubber membrane separator has been developed and the optimum conditions for determination of aniline (I) in water samples were established using standard solutions. The system comprised a sampling valve, a silicone-rubber membrane separation cell, a peristaltic pump and a spectrophotometric detector. The sample was injected into a carrier stream (1 ml/min) of 10 mM NaOH and a liquid extractant (20 mM HCl) was pumped at 0.7 ml/min through the separation cell. After alkalization with 40 mM NaOH, the extract was detected at 230 nm. The calibration graph was linear for 2-200 mg/ml of I with a detection limit of 1 mg/l. Recoveries were 91-103.5% and RSD (n = 12) was 1.2% for 50 µg/ml of I. Up to 200-fold amounts of phenol, acetic acid, butanoic acid and ethyl acetate relative to aniline did not interfere.
Aniline Spectrophotometry Interferences

"Determination Of Mercury(II) By Flow Injection Chemiluminescence Analysis With An Inorganic Coupling Reaction - Potassium Hexacyanoferrate(II)/luminol System"
Fenxi Huaxue 1996 Volume 24, Issue 6 Pages 699-702
Zhao, Z.Q.;Wang, Z.K.;Jia, Y.J.;Zhang, Z.J.

Abstract: Portions of standard Hg(II) solution were mixed with 0.5 mL 0.01 M HCl, 1.6 mL 0.1 mM K4Fe(CN)6 and the mixture was diluted to 10 mL with water. The solution was heated at 60°C for 12 min, cooled in an ice-bath for 3 min and 0.8 mL 0.01 g/l Cu(II) was added. A 100 µL portion of the mixture was injected at 3 ml/min into a homemade flow injection analyzer. (schematic shown), mixed with a reagent stream of 0.25 mM luminol in 0.01 M NaOH and the chemiluminescence intensity produced was measured. The calibration graph was linear from 0.8-40 µg/l Hg(II) and the detection limit was 0.22 µg/l. The RSD was 3.4% for the determination of 8 µg/l Hg. Most common ions were tolerated. The method was applied to the analysis of environmental waters, with recoveries of 90-95%.
Mercury Chemiluminescence

"Silver-diethyldithiocarbamate System For The Determination Of Arsenic By Flow Injection Analysis"
Fenxi Huaxue 1996 Volume 24, Issue 12 Pages 1429-1432
Liu, G.Q.;Wang, C.X.;Cao, F.X.

Abstract: Sample was introduced in the flow injection analysis system (diagram shown) to react with 1% KBH4 solution and the generated AsH3 was transferred by N2 carrier gas at 30 ml/min to an absorption cell containing silver diethyldithiocarbamate/triethanolamine solution in CHCl3, during which the gas flow was stopped for 4 min (i.e., 1 min after sampling). Having switched to the continuous spectrophotometric mode, the absorption was stopped and the absorption solution was allowed to flow-through the detection cell for measurement of the absorbance at 530 nm. The calibration graph was linear. When determining 0.3 µg/ml of As, the RSD (n = 11) was 4.8%. The method was used in the analysis of soil, with RSD of 3.1-6.2%. The sampling frequency was 15 per h.
Arsenic Spectrophotometry

"Online Monitoring Of Chemical Oxygen Demand In Environmental Waste Water By Flow Injection Spectrophotometry"
Fenxi Kexue Xuebao 1996 Volume 12, Issue 2 Pages 18-21
Fan Shihua, Fang Zhaolun

Abstract: A flow injection system (diagram given) for the online measurement of COD of waste water is described. The sample was injected into a carrier stream of water (0.27 ml/min) and after filtering, the sample stream was mixed with a reagent stream of 0.3 µM-cerium(IV) sulfate solution containing 4% H2SO4 at 0.27 ml/min in a reaction coil (20 m x 0.5 mm i.d.) heated at 100°C. The absorbance was measured at 320 nm vs. a reagent blank. The calibration graph was linear up to 100 µg/ml and the RSD (n = 7) was ~2% for 60 µg/ml. Results were within±10% of those obtained by the batch dichromate method on synthetic COD reference samples.
Chemical oxygen demand Spectrophotometry Filtration Heated reaction Method comparison

"A Study On Online Flow Extraction System For Atomic Absorption Spectrometry And Its Application"
Fenxi Shiyanshi 1994 Volume 13, Issue 3 Pages 73-76
Huang, H.P.;Lin, S.L.

Abstract: Solution of Cu or Au were treated with HCl to 2%, then 2 mL of 50% ammonium thiocyanate and 2 mL of 10% ascorbic acid were added. The solution was diluted to 50 mL with water and portions were loaded into a flow injection system containing a self-constructed gravitational phase separator (3 m x 1 mm i.d.) linked with a trisection connector, with water as the carrier stream and methyl isobutyl ketone as the extractant (flow ratio 25:1), and detection by flame AAS or graphite-furnace AAS. The detection limit for Cu by flame AAS was 1 µg/l and for Au by graphite-furnace AAS was 0.08 µg/l; the corresponding RSD were 1.8% and 4.9%. Up to 20 runs/h could be carried out.
Copper Gold Spectrophotometry Spectrophotometry Sample preparation MIBK Phase separator Solvent extraction

"Flow Injection Analysis Of Ammonium Nitrogen In Environmental Waters"
Fukuoka Kyoiku Daigaku Kiyo 1981 Volume 31, Issue 1 Pages 57-65
Oshima, Fumio (SFS)

Abstract: A continuous-flow, colorimetric method for the determination of NH4+ in water is described. (SFS)
Ammonium, nitrogen Spectrophotometry

"Voltammetric Determinations Of Environmental Pollutants At Microelectrodes"
GIT Fachz. Lab. 1998 Volume 42, Issue 11 Pages 1163-1167
Schwarz, J.;Kaden, H.;Enseleit, U.

Abstract: Different organic pollutants were determined voltammetrically in stationary and flowing solutions at microelectrodes (ME) and micro-array electrodes (MAE). These MEs and MAEs were used as voltammetric detectors under flow-through conditions in miniaturized electrochemical cells (wall-jet, thin-layer principle). Micro-disk electrodes from Au, Pt, and C with 25, 20, and 7 µm diameter, respectively, were especially advantageous in application and construction. The MEs are characterized by simple handling, robustness, low cost construction, and unproblematic application in aquatic and organic medium.
Organic compounds Electrode Voltammetry Electrode Electrode Electrode Electrode Electrode Apparatus Detector

"Determination Of Environmental Arsenic By Graphite Furnace Atomic Absorption Spectrometry After Formation Of Arsenic Hydride Using Flow Injection"
Huaxue Yu Nianhe 1990 Volume 1990, Issue 4 Pages 213-216
Zhu, Mingyang; Guo, Shaowei; Xu, Changsheng (SFS)

Abstract: The app. and conditions for the formation of arsenic hydride using flow injection were studied. Ce(NO3)4 were used as a matrix modifier. As was determined in river water and fine coal by graphite atomic adsorption spectrometry. As was first converted into hydride by 1% KBH4 using 2 M HCl as a carrier. I2-KI or Ce-KI solution was used to absorb the As hydride. The sensitivity of the method was 0.8 ng/mL, detection limit was 0.9 ng/mL, and abs. characteristic sensitivity was 8 x 10^-12 g. The variance and recovery were 6.3-12.6 and 91-97%, respectively. (SFS)
Arsenic Spectrophotometry Spectrophotometry Volatile generation Optimization

"Use Of A Novel Apparatus Based On The Injection Principle For Automatic Voltammetric Analysis"
Hung. Sci. Instrum. 1979 Volume 45, Issue 1 Pages 1-8
Feher, Z.;Nagy, G.;Bezur, L.;Szovik, J.;Toth, K.;Pungor, E.

Abstract: The injection measuring principle, capable of rapid serial analysis of individual sample solutions, is described. As examples from the field of environmental analysis, the determination of free Cl content and the determination of phenol and phenolic compounds by using a novel app. based on the injection principle is described. The Modul Momatic 100 S voltammetric analytical application consists of a 28-channel peristaltic pump, an automatic sample changer, an analysis unit, a controller and integrator unit, a recorder, and a printer. Modes of operating the app. are described and shown in diagrams.
Chlorine, free Phenols Phenol Voltammetry Apparatus Injector Review

"Thin Transducer As Detector For Trace Organics"
Ind. Res. Dev. 1981 Volume 23, Issue 5 Pages 148-153
houp, Ronald E.; Bruntlett, Craig S.; Kissinger, Peter T.; Jacobs, Wesley A. (SFS)

Abstract: A review with 14 references. The use of thin-layer electrochemical transducer, especially amperometric transducer, for chromatography and flow-injection anal. for trace organics in environmental, industrial, and biochemical study is discussed. (SFS)
Trace organics HPLC Apparatus Detector

"Electrochemical Analysis Of Sulfur Compounds Of Environmental Interest"
Int. J. Environ. Anal. Chem. 1985 Volume 20, Issue 3-4 Pages 167-177
Thomas, J.D.R.

Abstract: A review is presented, largely of work carried out at UWIST, with emphasis on the use of S2--selective electrodes for monitoring industrial liquors (e.g., black liquor) and effluents and sewage effluents and for monitoring the growth of S2--producing bacteria, of importance in the context of industrial spoilage, and also on flow injection analysis with use of ion-selective electrodes and on means of overcoming interference by H2O2. (30 references).
Sulfide Electrode Interferences Review

"Novel Flow Injection Approaches To Environmental Analysis"
Int. J. Environ. Anal. Chem. 1990 Volume 38, Issue 2 Pages 171-183
M. D. Luque De Castro; M. Valc&aacute;rcel

Abstract: An overview of the state of the art in Flow Injection Analysis for environmental control is presented The contributions to single- and multi-parameter determinations and potential of this technique for speciation are considered. Improvements resulting from the on-line use of separation techniques, of easy implementation, make an excellent feature which allows the user to address problems arising from complex matrices and/or low analyte concentration.
Review Speciation Multidetection

"Determination Of Organomercury And Mercury In Environmental Samples By Flow Injection Atomic Fluorescence Spectrophotometry"
Int. J. Environ. Anal. Chem. 1996 Volume 63, Issue 3 Pages 187-193
S. C. Edwardst; C. L. Macleod; W. T. Corns; T. P. Williams; J. N. Lester

Abstract: Environmental samples (dogfish and liver certified reference materials, eel and roach) were digested by heating for 4 h at 60°C with 20% tetramethylammonium chloride in a closed vessel. The digest was extracted with toluene, centrifuged, and the extract was mixed with 1 mL 1 mM cysteine or -thiosulfate. The aqueous phase was analyzed for organomercury by flow injection AFS. Total Hg was determined after microwave digestion of samples with 30% H2O2/HNO3/H2O. Sample (100 µL) was injected into a stream of water which was mixed with a stream (0.4 ml/min) of 25 g/l potassium peroxodisulfate and 1.2 g/l CuSO4 in 0.25 M H2SO4 for oxidation to Hg2+ in a 0.5 mL reaction coil. The flow then merged with a stream (0.5 ml/min) of 100 g/l SnCl2 in HCl for reduction to Hg(O) in a 1 mL reaction coil. The Hg(O) was carried in Ar (after separation in a gas liquid separator) to a hygroscopic tubular membrane for drying and to the AFS instrument. The calibration graph was linear for 5-1000 µg/l methylmercury ions and the detection limit was 2 µg/l. The RSD (n = 10) at 25 µg/l was 3.7%. The calibration graph for inorganic Hg was linear for 0.05-1000 µg/l and the detection limit was 0.02 µg/l. Extraction efficiences were 70-80%.
Mercury Methylmercury ion Fluorescence Sample preparation Sample preparation Reference material Extraction Phase separator Speciation

"Flow Injection Analysis - Thermospray Tandem Mass Spectrometry Of Triazine Herbicides And Some Of Their Degradation Products In Surface Water"
Int. J. Environ. Anal. Chem. 1996 Volume 64, Issue 4 Pages 265-278
Geerdink, R.B.;Berg, P.J.;Kienhuis, P.G.M.;Niessen, W.M.A.;Brinkman, U.A.T.

Abstract: Water sample (100 ml) was mixed with 7.8 g 1 M ammonium acetate and 1 mL 100 ng/ml 2H5-ethylamine-atrazine (internal standard), adjusted to pH 7 with NH4OH or glacial acetic acid, then a portion (30 ml) was applied to a 1 g Baker PolarPlus SPE cartridge at 3 ml/min. After washing with water, triazines and their degradation products were eluted with 2 x 2.5 mL methanol, the combined eluate was evaporated to 1 ml, diluted to 10 mL with 0.11 M ammonium acetate, and portions (2 or 5 ml) were analyzed directly by flow injection thermospray tandem MS (operating conditions given). Compounds were identified with µtiple reaction monitoring, where four product ions were analyzed after a prior screening procedure. Calibration graphs were linear from 0.05-1 µg/l. Detection limits were 0.05-0.15 µg/l and 0.2-0.45 µg/l for triazines and their degradation products, respectively. The corresponding recoveries were generally >82% and >60%. The RSD (n = 10) were ?. Results were comparable to those obtained by GC.
Herbicides, triazine Mass spectrometry Method comparison

"Immunochemical Techniques And Immunosensors For The Analysis Of Dealkylated Degradation Products Of Atrazine"
Int. J. Environ. Anal. Chem. 1996 Volume 65, Issue 1-4 Pages 113-126
Wittmann, C.

Abstract: Field format dipstick and automated flow injection immunoanalysis (FIIA) methods are described. De-ethylatrazine, the major metabolite of atrazine, was chosen as representative analyte and was dissolved in ethanol. For the dipstick format, antibodies were immobilized on a nylon membrane. For the FIIA method, microglass beads (diameter 50-100 µm), surface modified with carboxylic groups, were used as support. Horseradish peroxidase was used as tracer and goat anti-rabbit IgG as primary antibody. The dipstick format gave a measurement range of 0.1-10 µg/l de-ethylatrazine, the FIIA 0.01-10 µg/l. Both formats enabled water and liquid food samples to be measured without the need for enrichment or clean-up steps. For soil samples, two extraction steps can be eliminated from the normal requirements for GC analysis. The two immunoassays gave results in good agreement with those from GC.
Atrazine Immunoassay Sensor Glass beads Immobilized enzyme Method comparison Nylon

"Advances In Analytical Chemistry In 1995"
J. Anal. Chem. 1997 Volume 52, Issue 2 Pages 178-189
M. M. Buzlanova

Abstract: Research in analytical chemistry carried out in Russia during 1995 is described. The discussion is divided into subject areas including standardization of analytical methods, automation and use of computers, sample preparation, individual techniques (e.g. MS, XRF, FIA) and sample type (e.g., environmental materials, organic compounds, high-purity compounds and noble metals). Advances in analytical instrumentation are described and future trends in analytical chemistry are outlined.
Review

"Cold Vapor Generation For Inductively Coupled Argon Plasma Atomic-emission Spectrometric Analysis. 3. Mercury"
J. AOAC Int. 1994 Volume 77, Issue 2 Pages 473-480
Anderson, K.A.;Isaacs, B.;Tracy, M.L.;Moller, G.

Abstract: Sample was digested with concentrated HNO3 and K2CrO4 for 6-12 h at room temperature and then for 24 h at 95°C, and the digest was treated with enough saturated KMnO4 solution to surpass the endpoint, which is recognized when the solution remains a clear purple or a brown precipitate remains after mixing. The mixture was heated at 70-95°C for 10 min then treated dropwise with saturated oxalic acid solution until it became clear and colorless or, for soils the samples changed from dark brown to milky white, and vortex-mixed. The resulting solution was mixed with 10 M HCl and 6% NaBH4 in 5% NaOH in a continuous-flow manifold (diagram given) and subjected to ICP-AES with measurement at 194.232 nm. The instrumental detection limit was 0.2 µg/l. The method was used to analyze biological materials and environmental materials, including plants, soil and water (which was analyzed directly). Recoveries were 68.4-97.0%.
Mercury(II) Sample preparation Spectrophotometry

"Simultaneous Determination Of Arsenic, Selenium, And Antimony In Environmental Samples By Hydride Generation For Inductively Coupled Plasma Atomic-emission Spectrometry"
J. AOAC Int. 1995 Volume 78, Issue 4 Pages 1055-1060
Kim A. Anderson and Brandon Isaacs

Abstract: Two digestion procedures (details given) were used in which a 1 g wet, 0.25 g dry or a 10 mL water sample was heated on a programmed heating block with HNO3 followed by boiling in H2SO4/HClO4. Soils (0.25 g) were digested with HCl. After digestion, the samples were treated with HCl. As, Se and Sb were reduced simultaneously in a continuous-flow manifold (diagram given) by mixing with NaBH4 and HCl-KI. The resulting hydrides (SeH2, SbH3 and AsH3) were separated by a Meinhard nebulizer. ICP-MS was performed with use of a Model Perkin-Elmer P-40 ICP with measurements at 193.696, 196.026 and 231.147 nm for As, Se and Sb, respectively. The detection limits were 0.55, 1 and 0.41 µg/l for As, Se and Sb, respectively. Their corresponding recoveries were 81-109, 87-108 and 65-123%. The method had good precision and accuracy (RSD not stated).
Antimony Arsenic Selenium Mass spectrometry Sample preparation Simultaneous analysis Volatile generation Volatile generation

"Speciation And Determination Of Dissolved Iodide And Iodine In Environmental Aqueous Samples By Inductively Coupled Plasma Atomic-emission Spectrometry"
J. AOAC Int. 1996 Volume 79, Issue 3 Pages 751-756
Kim A. Anderson, Barbara Casey, Elmer Diaz, Peter Markowski, and Brent Wright

Abstract: Samples (5-10 ml) were filtered and diluted tenfold if the salt concentration was >1%. Iodide was determined after filtration by oxidation to I2 in situ with 5 M H2SO4/0.1 M NaNO2 in a simplified continuous-flow manifold (diagram given); a standard nebulizer separated I2 which was measured at 206.16 nm by ICP-AES with use of a Model Perkin-Elmer P-40 ICP-AES instrument with an AS-90 autosampler. I2 was determined without the use of the oxidation reagents. Samples containing both iodide and I2 were analyzed with the oxidizing reagent for the total iodine, without the oxidizing reagents for I2 and iodide was calculated by the difference of the two measurements. The method was applied to seawater, brine and fresh water. Recoveries were 86.5-118.6% with an average of 98.2%. The stability of I2 in environmental samples was briefly investigated.
Iodine Sample preparation Spectrophotometry Speciation

"The Role Of Discrete Sample Injection In Trace Mercury Analysis By Atomic-fluorescence Spectrometry"
J. Autom. Methods Manag. Chem. 1996 Volume 18, Issue 4 Pages 153-162
P. B. STOCKWELL, W. T. CORNS, and N. BRAHMA

Abstract: Cold vapor AFS instrumentation for routine water analysis (to the levels and sampling frequency demanded by recent UK legislation) developed by P S Analytical Ltd. involving the 'method chaining' of continuous-flow and discrete-sample-injection techniques is described. Although the former technique is the more sensitive, latter takes advantage of the sensitivity of AFS that permits the discrete introduction of sample volumes of 50-200 µL, which minimizes self-absorption and matrix interference and extends the usable range of the system up to 10 ppm.
Mercury Fluorescence Interferences

"Stabilized Filter-supported Bilayer Lipid Membranes (BLMs) For Automated Flow Monitoring Of Compounds Of Clinical, Pharmaceutical, Environmental And Industrial Interest"
J. Autom. Methods Manag. Chem. 1997 Volume 19, Issue 1 Pages 1-8
DIMITRIOS P. NIKOLELIS and CHRISTINA G. SIONTOROU

Abstract: The method and apparatus for the preparation of phosphatidylcholine/dipalmitoylphosphatidic acid membranes, containing enzymes or antibodies, cast on glass microfiber or polycarbonate ultrafiltration membranes are described [cf. Anal. Chem., 1995, 67, 936; Electroanalysis (N.Y.), 1995, 7, 531, 1082]. The membranes were used in flow injection amperometric determinations of (i) substrates (e.g., acetylcholine, penicillin and urea) of hydrolytic enzymes, and (ii) antigens (e.g., thyroxine and triazine herbicides).
Acetylcholine Penicillin Urea Thyroxine Triazines Clinical analysis Biochemical analysis Amperometry Supported lipid membrane Polycarbonate membrane Glass microfiber

"Flow Injection Analysis And Biosensors: Applications For Biotechnology And Environmental Control"
J. Biotechnol. 1990 Volume 14, Issue 1 Pages 71-79
H. L&uuml;di*, M. B. Garn, P. Bataillard and H. M. Widmer

Abstract: Our experience in industrial bioprocess monitoring and environmental control let us develop a concept for biosensor research which distinguishes itself from other, more popular, approaches. Biosensors must improve and/or simplify existing state-of-the-art analysis systems. Only the parallel development of biosensors and their complementary metrology leads to industrially sound solutions. The combination of flow injection analysis with immobilized enzymes in the form of enzyme columns is already used today for the solution of online analytical problems in bioprocesses and environmental control. Combinations of flow injection analysis (FIA) and biosensors for monitoring of bioprocesses are discussed. For example, the uptake of glucose by cultures of S. Cervisiae was monitored with an online sensor consisting of glucose oxidase deposited on a microelectrode operated at +400 mV vs. Ag - AgCl to detect H2O2. Another manifold system was described for monitoring downstream processing of NN-dimethylformamidase (details given). Strategies for using immobilized enzymes in FIA - biosensor systems for environmental analytical chemistry are also discussed.
Sensor Biotechnology Immobilized enzyme Enzyme Column

"Amperometric Biosensor For The Determination Of Phenolic Compounds Using A Tyrosinase Graphite Electrode In A Flow Injection System"
J. Biotechnol. 1993 Volume 31, Issue 3 Pages 289-300
F. Ortega*, E. Dom&iacute;nguezG. J&ouml;nsson-Pettersson and L. Gorton

Abstract: Selective and sensitive devices for the monitoring of phenol and phenolic compounds are required in clinical and environmental analysis. This paper describes a biosensor for the analysis of phenolic compounds in a flow injection system. The enzyme electrode is based on the use of immobilized tyrosinase and the amperometric detection of the enzymatic product at -50 mV vs. SCE. The enzyme is covalently immobilized on the surface of a carbodiimide-activated graphite electrode. The biosensor responds to a variety of phenolic substrates with different conversion efficiencies. The detection limit for phenol is 0.003 µM (S/N = 3), a quantification limit of 0.01 µM (rsd 3.7%), and an extended dynamic range up to 5 µM is achieved with a sample frequency of 110 samples per hour.
Phenols Amperometry Electrode Clinical analysis Sensor Immobilized enzyme

"Fate Analysis Of Phosphorus Compounds In Environmental Waters By Flow Injection Analysis And High Performance Liquid Chromatography"
J. Flow Injection Anal. 1986 Volume 3, Issue 1 Pages 37-46
Norimasa YOZA,* Yasushi SAGARA, Hitomi MORIOKA, Takashi HANDA, Hisanobu HIRANO,Yoshinobu BABA and Shigeru OHASHI

Abstract: The concept of 'fate analysis' of phosphorus compounds in aquatic media was explained with several examples; a phosphorus compound is dissolved in a sample water to be examined and the conversion of its chemical form is monitored as a function of time to evaluate the quality - the chemical property and biological activity - of the water. The difference between the concepts of speciation and fate analysis was described. The interchangeable use of a high-pressure flow injection system as an HPLC detector was recommended to achieve such fate analysis of pyrophosphate and tripolyphosphate in deionized water and river water. The FIA system was improved with respect to the preparation method of a Mo(V)-Mo(V1) reagent and the use of a dry reactor with a heating aluminum block (140°C). Fate analysis in deionized water indicated the abnormally high catalytic activity of the deionized water for the hydrolysis of pyrophosphate and tripolyphosphate. The catalyst with pseudo-enzymatic function in the deionized water was deactivated by being autoclaved at 121°C . Pyrophosphate and tripolyphosphate in river water were hydrolyzed more rapidly than one could expect from kinetic data in chemical hydrolysis, but more slowly than in the deionized water.
Phosphorus HPLC Spectrophotometry

"Simultaneous Determination Of Cyanide And Sulfide By Reversed Flow Injection Analysis"
J. Flow Injection Anal. 1994 Volume 11, Issue 1 Pages 58-67
Huiliang, M.;Jingfu, L.;Jianzhang, F.;Yue, G.

Abstract: A diagram of the optimized manifold is given. Sample was mixed with a stream of EDTA/HCl solution (0.4 ml/min) to form the donor stream which was heated to 60°C whilst passing through a PTFE coil (1 m x 0.7 mm i.d.) in the thermostat. Liberated HCN diffused through the PTFE membrane and was adsorbed by 5 mM NaOH acceptor solution the acceptor solution was then mixed with chloroamine-T/phosphate buffer solution Pyridine-barbiturate reagent was injected and the absorbance was measured at 494 nm for the separated cyanide (I). Alternatively, the donor stream was adjusted to pH 4.7 by mixing with a sodium acetate solution and then with an Fe(III) (1,10-phenanthroline chromogenic reagent. The absorbance was measured at 505 nm for sulfide (II). The detection limits of I and II were 0.2 and 0.4 mg/;, respectively. The corresponding RSD (n = 11) were 0.5 and 0.7% at 3 and 10 mg/l, respectively. Carbonate, nitrate, formaldehyde, iodide, thiocyanate and bromide did not interfere.
Cyanide Sulfides Spectrophotometry Reverse Interferences pH Heated reaction Simultaneous analysis Gas diffusion Teflon membrane Chromogenic reagent

"Application Of Membrane-separation To Flow Injection Analysis"
J. Flow Injection Anal. 1994 Volume 11, Issue 1 Pages 24-33
Aoki, T.

Abstract: A review is presented of membrane-separation techniques in FIA. Covering the period 1991-1993. Most of the studies are of an environmental nature and use gas-permeable membranes and ion-exchange membranes such as Nafion, etc. (17 references).
Ion exchange Nafion membrane Review

"Automated Flow-through Analysis Of Trace Elements In Marine Chemistry"
J. Flow Injection Anal. 1996 Volume 13, Issue 1 Pages 3-13
Nakayama, E.

Abstract: A review is presented of automated flow-through analysis of particularly seawater with electrolytic and chelating resin pre-concentration as well as detection by e.g. fluorimetric, chemiluminescence and catalytic methods, especially that suitable for in situ shipboard analysis. (12 references).
Trace organics Chemiluminescence Fluorescence Review Remote instrument Catalysis Preconcentration Chelation Resin

"Determination Of Cobalt In Seawater By Flow Injection Analysis"
J. Flow Injection Anal. 1996 Volume 13, Issue 2 Pages 168-168
Oguma, K.

Abstract: A brief review is presented, which includes techniques especially for in situ flow injection analysis of seawater from various depths from on board the research ship. (5 references).
Cobalt Remote instrument Review

"Flow Injection Determination Of Cyanide With Use Of An Immobilized Enzyme"
J. Flow Injection Anal. 1996 Volume 13, Issue 2 Pages 138-147
Deguchi, T.;Fukaura, K.;Norimatsu, S.;Minami, S.;Tanaka, A.;Sanemasa, I.

Abstract: Rhodanese was immobilized on 200-400 mesh aminopropyl-controlled pore glass beads (particle size 585 angstrom and surface area 45.1 m2/g) by the action of glutaraldehyde in Tris buffer of pH 8.6. Sample (100 µL) was injected into a stream of 10 mM Tris buffer of pH 8.6 at 0.7 ml/min and merged with a stream of 5 mM Na2S2O3 at 0.3 ml/min before entering the immobilized enzyme reactor (4 cm x 2 mm i.d.) at 0°C. The generated thiocyanate ion was mixed with a reagent stream of 5 mM Fe(III) in a reaction coil (2 m x 0.5 mm i.d.) and detection was at 460 nm. The calibration graph was linear from 0-1 mM cyanide, with a detection limit of 15 µM. When determining 0.5 mM cyanide, the RSD was 2.3%. Only ascorbate interfered. The immobilized rhodanese was stable for at least 10 h when used continuously. The sampling frequency was 20/h. The method was applied to the analysis of environmental and clinical samples.
Cyanide Spectrophotometry Interferences Controlled pore glass Immobilized enzyme

"Biosensors In Flow Injection Systems For Biomedical Analysis, Process And Environmental Monitoring"
J. Mol. Recognit. 1996 Volume 9, Issue 5-6 Pages 658-663
Canh Tran-Minh

Abstract: This paper presents the construction of various biosensors using thin- film layers incorporated in flow injection devices, providing automated systems for biomedical analysis, process and environmental monitoring. A urease sensor has been developed in conjunction with a flow injection system for the automatic determination of urea. Use of the spraying immobilization technique gives rise to a response time of a few seconds, which allows sample throughputs up to 200 h-1. With a penicillin biosensor adapted in an appropriate cell detection, online measurements of penicillin V in the fermentation broth are achieved during the whole fermentation process; the results are compared with the HPLC method. Linearity, sensitivity and reproducibility of the biosensor are studied with regards to sample dilution in a stirred flow detection cell to provide optimal operating conditions. Measurements without any change in parameters are obtained during the whole fermentation process. Acetylcholinesterase sensors have been used in batch systems for the determination of pesticides, but they require large amounts of substrate. When those enzyme sensors are combined with flow injection systems, only small volumes (100 µL) of substrate are injected into the carrier stream and an automated system can be obtained for continuous control of water quality.
Urea Penicillin V Sensor Process monitoring

"Analysis Of Oxothio Arsenic Species In Soil And Water"
J. Prakt. Chem. Chem. Ztg 1996 Volume 338, Issue 1 Pages 55-59
Georg Schwedt, Melanie Rieckhoff

Abstract: Arsenic species in alkaline extracts of sulfidic and arsenic slags as well as in water in mines were analyzed by ion chromatography and capillary zone electrophoresis. The total arsenic was determined in both kinds of samples by FIA-hydride AAS, in the slags after microwave induced pressure digestion, and in the untreated solid samples also by RFA. Arsenate, arsenite and monothioarsenate ions could be identified and quantified as stable arsenic species.
Arsenate ion Arsenothioate ion Arsenite Sample preparation Spectrophotometry Speciation Volatile generation Volatile generation

"Preconcentration And Colorimetric Determination Of Iron(III) By Sequential Injection Analysis"
Lab. Rob. Autom. 1996 Volume 8, Issue 3 Pages 149-156
E. Rub&iacute;, R. Forteza, V. Cerd&aacute;

Abstract: A sequential injection analysis system was developed for the spectrophotometric determination of Fe(III) in fresh and seawater. Water acidified to pH 3-3.5 with HNO3 was injected into the system (flow diagram of instrumental set-up given) and Fe was pre-concentrated on a Chelex 100 microcolumn inserted in the manifold. The Fe retained by the resin was then eluted with 2 M HNO3. At this point, the stream was merged with KSCN stream and the resulting Fe-KSCN complex was detected by monitoring the absorbance changes with a spectrophotometer. The effects of flow rate, pre-concentration column i.d., HNO3 concentration and pH on the determination were investigated. The detection limit was 0.02 mg/l of Fe(III) with an RSD (n = 10) of 3%. Recoveries were >82%. The method was also suitable for drinking water.
Iron Spectrophotometry Sequential injection Preconcentration Chelex

"Robotic Sample Pretreatment Coupled With Flow Injection Online Sorption Preconcentration-electrothermal Atomic Absorption Spectrometry For The Determination Of Copper In Environmental And Biological Materials"
Lab. Rob. Autom. 1998 Volume 10, Issue 5 Pages 293-298
Alfredo Velasco-Arjona, Mar&iacute;a Dolores Luque de Castro, Elissaveta Ivanova, Freddy Adams

Abstract: An automated robotic method for sample pretreatment was developed for copper determination in environmental and biological materials at the low microgram per g level. The robotic station performing the preliminary operations as weighing of sample and acid digestion was coupled with the flow injection (FI) online sorption pre-concentration. of the pyrrolidine dithiocarbamate chelate of copper on the walls of a PTFE knotted reactor (KR) and subsequent electrothermal atomic absorption spectrometry (ETAAS) determination of copper. The accuracy of the method was demonstrated by the anal. of environmental and biological certified reference materials. The precision is 1.4-2.5% relative standard deviation in the 4-50 µg/g concentration. range.
Copper Spectrophotometry Automation Robot On wall preconcentration Knotted reactor Pyrrolidine dithiocarbamate Reference material

"Automatic Determination Of Mercury At The Lower Ng/l Levels"
LaborPraxis 1995 Volume 19, Issue 8 Pages 32-34
Baasner, J.

Abstract: An AS 90 or 91 sample dispenser and a flow injection AAS system (FIMS 100 or 400) with a high-intensity radiation source, a long-path cuvette and a wavelength-specific detector were used in the method. The working range is 20 ng-40 µg/l of Hg and the detection limit 5 ng/l. The method was used for the analysis of Hg in rain water, urine, blood, lemon leaves and sludges. Results agreed well with certified values. When the sample is pre-concentrated by amalgamation and blank values are determined and taken into account the working range and detection limits are 1-200 and 0.3 ng/l, respectively. With the use of amalgamation recoveries of 10 ng/l of Hg added to drinking water were 98-102%. The procedure is applicable to the hydride-generation AAS determination of other elements, e.g., As, Se or Sb.
Mercury Arsenic Selenium Antimony Spectrophotometry Spectrophotometry Amalgamation FIMS Reference material Volatile generation Volatile generation

"Determination Of Trace Copper By Flame Atomic Absorption Spectrometry Coupled With Flow Injection Online Coprecipitation Preconcentration"
Lihua Jianyan, Huaxue Fence 1998 Volume 34, Issue 6 Pages 246-255
Jin Xin, Liu Jinsong, Chen Hengwu and Mao Xueqin

Abstract: A method for the determination of trace Cu by FIA-FAAS online co-precipitation pre-concentration was presented. FIA online co-precipitation technique for the pre-concentration of trace Cu(II) with DDTC-Ni2+ as co-precipitating carrier was hyphenated with FAAS determination The co-precipitation was carried out in 0.3 M HNO3 medium, the ppt. was collected in a knitted reactor, and the ppt. was dissolved by Me iso-Bu ketone (MIBK) and transferred directly into the nebulizer burner system of a FAA spectrometer. The detection limit (3s) was 0.2 µg L-1, the linear range 0-0.08 mg L-1, and the relative standard deviation 3.0%. The method was applied to determine trace Cu in environmental and biological standard reference materials, and water samples with satisfactory results.
Copper Spectrophotometry Preconcentration Reference material Coprecipitation Diethyldithiocarbamate Knotted reactor MIBK

"Determination Of Arsenic And Selenium By Injection Combined With Cold-trap Collection Of Hydride And Continuous-flow Hydride Atomic Absorption Technique"
Magy. Kem. Foly. 1996 Volume 102, Issue 3 Pages 248-256
Siska, R.;Borszeki, J.;Gegus, E.

Abstract: Continuous-flow and flow injection hydride-generation AAS methods for the determination of As and Se are described, which involve collection of hydrides in a cold trap (diagrams of manifolds given). The detection limits were 10^-20 pg/ml. The results obtained for international standards agreed with the internationally accepted values. Reproducibility was good. The methods were applied to environmental materials (food and water).
Arsenic Selenium Spectrophotometry Cold trap Reference material

"Instrumental Analytical Method For The Determination Of Traces Of Lead By Atomic Absorption Measurements In A Flow System"
Magy. Kem. Foly. 1996 Volume 102, Issue 12 Pages 542-545
Papp, L.

Abstract: A hydride-generation system for the determination of Pb in air (passed through HNO3) and water by quartz-cell AAS is described and illustrated. Flow injection manifolds incorporating the system are also shown. The detection limit in a 0.2 mL injection is 17 ng.
Lead Spectrophotometry

"Sorption Preconcentration And Flame Atomic Absorption Determination Of Chromium(VI) Using Hydraulic High-pressure Sample Introduction"
Magy. Kem. Foly. 1998 Volume 104, Issue 4 Pages 153-163
A. G&aacute;sp&aacute;r, J. Posta and Cs. S&oacute;gor

Abstract: Sorption flow injection (FI) pre-concentration procedure was combined with hydraulic high-pressure nebulization sample introduction (HHPN) and flame atomic absorption spectrometric detection (FAAS). The online FI-HHPN/FAAS system was constructed and a method was developed for online sorption and determination of Cr(VI). A polyether-ether-ketone, PEEK loop pre-concentration unit was used for the sorption of Cr-pyrrolidinedithiocarbamate complexes. The detection limit (3s) of the pre-concentrated 5 mL sample solution containing Cr(VI) was 0.54 ng/mL. The precision was 2.8%RSD for 50 ng/mL Cr(VI) (N=6). The method was applied for the determined of Cr(IV) in some natural samples. It was proved that the total chromium content of the samples containing large amt. of organic materials can quant. be converted into Cr(VI) by ashing at 800°C in the presence of oxygen. Thus trace level total chromium contents of various samples were determined after ashing and sorption pre-concentration in form of Cr(VI).
Chromium(VI) Sample preparation Spectrophotometry Nebulizer Interface Polyetheretherketone Preconcentration Speciation Complexation

"Semiautomated Determination Of COD In Wastewater Samples"
Mem. Sch. Eng. Okayama Univ. 1980 Volume 14, Issue 2 Pages 119-129
Korenaga Takashi;Ikatsu Hisayoshi;Ikatsu Hisayoshi;Moriwake Toshio;Takahashi Teruo

Abstract: A new method based on the principle of flow injection analysis is presented for the semiautomated determination of chemical oxygen demand (COD) in environmental water samples. The method is rapid and continuous, and suitable for the monitoring of COD in wastewaters. The apparatus used was simply constructed by parts commercially available for high performance liquid chromatography. Teflon tubing heated with a boiling watAr was used as a reactor and simultaneously used for mixing coils and transmission lines. The operating conditions were examined to apply the determination of COD in wastewaters by using glucose as a standard COD substance. The procedures recommended are as follows: Both 4.9 x l0-4 M potassium permanganate and 6. 7 % sulfuric acid solutions are individually pumped, 20 pL of a sample solution is injected into the flow of the sulfuric acid solution, and then mixed with a mixing joint. The mixed solution is transported to a flow cell situated in a spectrophotometer fixed at a wavelength of 525 nm, and decrements of absorbance are recorded. The peaks were reproducibly obtained at a concentration-range of 10^-200 mg-COD 1 L-1. Chloride up to 1000 mg L-1 was not interfered at all. Various wastewater samples were analyzed by the proposed method at a sampling rate of 30 samples .per hour, and the apparent COD values obtained were compared with the manual COD ones obtained by JIS method.
Chemical oxygen demand Spectrophotometry Interferences Method comparison Standard method

"Flow Injection Analysis - A New Analytical Technique"
Newsletter Chem. Soc. South Pacific 1989 Volume 4, Issue 3 Pages 3-6
Koshy, K.C.

Abstract: An introductory review is presented in which a single-line system for determination of Cl- is described and applications in environmental analysis are cited. (3 references).
Review

"Applications Of Flow Injection Analysis In Agricultural And Environmental Analysis"
Flow Injection Atomic Spectroscopy 1989 Volume 7, Issue 1 Pages 225-257
Zagatto, E.A.G.;Krug, F.J.;Bergamin, H.;Jorgensen, S.S.

Abstract: A review, with 70 references, is presented on flow injection analysis coupled with AAS or AES.
Spectrophotometry Spectrophotometry Review

"Determination Of Arsenic Species In Environmental And Biological Samples"
Pure Appl. Chem. 1992 Volume 64, Issue 4 Pages 575-590
M. Morita and J. S. Edmonds

Abstract: Identification and quantitative determination methods of arsenic species in environmental and biological samples are discussed. Isolation followed by molecular spectroscopic determination is necessary for rigorous identification while element-specific detections coupled with separation techniques are the choice for quantitative determination. Analytical figures of merit are given for the methods applicable to a specific matrix evaluating hydride generation technique, high performance liquid chromatography coupled with atomic absorption, ICP atomic emission, ICP mass spectrometric detection, thin layer and gas chromatography with atomic absorption spectrometric area that requires attention as it still represents the main source of problems including matrix interference, incomplete recovery and analyte instability.
Arsenic Spectrophotometry Speciation

"Analytical Methodology For The Determination Of Aluminum Fractions In Natural Fresh Waters"
Pure Appl. Chem. 1996 Volume 68, Issue 8 Pages 1597-1638
N. Clarke, L.-G. Danielsson and A. Sparen

Abstract: The distribution among different species, ''speciation'', is essential for understanding the toxicity, bioavailability and transport mechanisms for elements in the natural environment. The distribution of Al among different species has been in focus during the last twenty years or so, and many methods for fractionating Al have been developed. Most of them are operationally defined, since validation of what is really measured in natural systems is very difficult. This review is a thorough and critical survey of the existing methods for Al fractionation in natural waters, that covers the literature up to and including June, 1994. The methods have been classified into six groups, according to the principles used: 1) Kinetic or Binding Strength Discriminations; 2) Ion Chromatographic Separations; 3) Size Exclusion; 4) Non-Invasive Methods; 5) Ion Mobility in an Electric Field; 6) Minimized Disturbance. In addition to this, in order to validate the different techniques, we scrutinize some of the method comparisons published.
Aluminum Chromatography HPIC SEC Nuclear magnetic resonance Chelation Speciation Review

"Effects Of Ecological And Cropping Factors On β-glucan Content In Oats"
Rostl. Vyroba 1996 Volume 42, Issue 1 Pages 29-33
Hubik, K.; Tichy, F.

Abstract: Exact field trials were carried out mostly with registered oat genotypes at Bystrice nad Pernstejnem and Krukanice in 1993. Effects of the location, genotype and nitrogen fertilization on the content of water-soluble β-glucans in grain dry matter were investigated. It was determined on the basis of increasing calcofluor fluorescence emission (Sigma-Aldrich, USA) caused by binding this dye to β-glucans. A method of flow injection analysis as modified by Jorgensen (1988) using a device of his own construction was used. Barley β-glucans were used as a standard. Results were expressed in percentage. Experimental data were processed by analysis of variance using STATGRAPHICS program. Results of the trial are summarized in Tab. II. At significance level of P = 0.05, β-glucan content in oat grain was the most affected by the genotype and then by the location. Effects of fertilization were not significant. Furthermore, Tab. II suggests highly significant (P = 0.05) interactions, such as genotype x location and genotype x fertilization, where the genotype x location interaction shows a higher proportion as determined by F-ratio. Statistical results obtained by analysis of variance are presented in greater detail in Tabs. III to V. Tab. III evaluates effects of the genotype on β-glucan content in oat grain. On the average of two locations, the highest content of β-glucan was determined in the genotype Adam (3.0%) which significantly differed from the other genotypes studied. The genotype Zlatak and line KR 9506 showed tile lowest average β-glucan contents both being 1.9%. The other genotypes can be divided into two groups between which is a significant difference. The first group includes genotypes David, Auron and Ardo. The last one is a transition to the other group which consists of Abel and Flamingsnova. Effects of fertilization variants on β-glucan content is given in Tab. V. The difference between the average β-glucan content in oat grain in all of investigated genotypes in the variant with the highest effect, i.e. N-a and N-bl and the variant with the lowest effect, N-0, was 0.2% only. That corresponds with the results in Tab. II which showed insignificant effects of the fertilization variant on β-glucan content in oat grain. The other fertilization variants, N-c and N-b, were transitional ones and did not show significant influence. The last factor which can affect β-glucan content in oat grain was the location. Tab. VI shows highly significant difference in the average β-glucan content of all genotypes studied at two locations. The effect of the location on the average β-glucan content in grain of eight genotypes is illustrated in Fig.2. Six genotypes (Abel, Ardo, Auron, David, Zlatak and KR 9046) had average β-glucan contents higher at Bystrice nad Pernstejnem. The highest difference as compared to the location Krukanice was found in the genotypes Ardo and Auron. In contrast, Adam and Flamingsnova reached the highest β-glucan content in grain at the location Krukanice. Among all genotypes, the genotype Adam showed the highest difference (1%). With regard to highly significant differences in β-glucan content in grain of grown genotypes at both locations, it is necessary to study this character under different soil and climatic conditions, and then to elaborate variety zoning.
β-Glucan Fluorescence

"Coupled Chromatography In Pesticide Residue Analysis"
Sci. Total Environ. 1993 Volume 132, Issue 2-3 Pages 105-114
Piet van Zoonen

Abstract: An overview is given of the applicability of coupled chromatographic systems in pesticide residue analysis. These systems can be based on liquid chromatography (LC) coupled to itself (LC-LC) or to GC (LC-GC) or on GC-GC combinations. The main advantage of coupled chromatographic techniques is the enhancement of both sensitivity and selectivity combined with a high potential for automation. However, in pesticide residue analysis too high a selectivity may prove to be a drawback, since it limits the scope of the analytical procedure. In order to circumvent this problem with the application of capillary GC, which is a highly selective end-method, the coupling of capillary GC to flow injection techniques and low resolution LC techniques (such as gel permeation chromatography and separation on solid phase cartridges) can be of great importance. The advantages and drawbacks of coupled chromatographic and flow injection techniques coupled to capillary GC are discussed in relation to the analysis of pesticide residues in environmental and biological samples.
Pesticides GC Interface Post-column derivatization Review

"Kinetics Of Copper(III)/(II) Tetraglycine Reactions With Sulfite. Analytical Potentialities"
Spectrosc. Lett. 1998 Volume 31, Issue 7 Pages 1495-1512
Deborah Yoshida; Horacio D. Moya; Rodrigo L. Bonif&aacute;cio; Nina Coichev

Abstract: The oxidation of Cu(II)/tetraglycine complex in borate buffer (pH=9.2) in aqueous medium, by dissolved oxygen is strongly accelerated by S(IV). The reaction is adequate for S(IV) determination as the concentration of (Cu(H-3G4)]- formed is proportional to SO32- concentration. The [Cu(H-3G4)]- presents a maximum absorbance at 365 nm (b.epsi = 7400 mol-1.L.cm-1) and it was followed spectrophotometrically by flow injection analysis procedure. The detection limit was 7 x 10^-6 mol.L-1 and the linear regression showed a standard deviation of 0.02% (n=5). Kinetics studies showed the catalytic effect of some transition metal ions, "which can be present in environmental samples, in the oxidation of S(IV). The pseudo-first-order rate constants were determined in the presence of formaldehyde.
Sulfur(IV) Sulfite Spectrophotometry Kinetic Indirect Interferences

"Applications Of A Mercury-vapor Atomic-fluorescence Detector"
Spectroscopy 1991 Volume 6, Issue 7 Pages 39-41
Stockwell, P.B.;Grillo, A.C.

Abstract: The applications of an automatic Hg detector based on atomic fluorescence principles are described. The instrument can be used to detect Hg in aqueous media over a wide linear-dynamic range and was successfully applied to the determination of total, inorganic and organic Hg in aqueous environmental samples using automatic continuous-flow and flow injection modes (brief details and schematic diagrams given). In combination with a trapping system based upon adsorption - desorption of Hg on to Au-impregnated sand, the detector was also used to determine the Hg concentration. in air or gaseous samples for application in the analyzes of urban stack emissions and natural gas feedstocks on a static or continuous basis.
Mercury(II) Ethylmercury Methylmercury ion Phenylmercury Mercury Fluorescence Automation

"Hyphenated Techniques Applied To Environmental Speciation Studies"
Trends Anal. Chem. 1992 Volume 11, Issue 1 Pages 17-26
O. F. X. Donard and F. M. Martin

Abstract: A discussion is presented on hyphenated techniques, using online and offline sample pre-concentration, for the speciation of trace metals in environmental materials; the former includes flow injection analysis and hydride generation methods coupled to cryogenic trapping, the latter covers all GC and LC techniques coupled to a wide variety of detectors. Future trends for speciation, including the use of SFC techniques and ICP-MS, are also described.
Metals, trace Sample preparation Spectrophotometry Review Preconcentration Volatile generation Speciation Volatile generation

"Analytical Monitoring Systems Based On Photocatalytic Oxidation Principles"
Trends Anal. Chem. 1996 Volume 15, Issue 3 Pages 151-156
Gary K. -C. Low* and Stephen R. McEvoy

Abstract: The formation of various anions resulting from the photocatalytic degradation of different organic compounds and pollutants in water are tabulated. Determination of the anions produced can be performed by ion chromatography or multi-sensor flow injection analyzer.s. Schematic diagrams of various instruments based on photocatalytic oxidation are presented. Problems associated with the monitoring systems are discussed. (17 references).
Anions Sensor HPIC Photochemistry Review

"Polar Organic Pollutants From Textile Industries In The Waste Water Treatment Process - Biochemical And Physico-chemical Elimination And Degradation Monitoring By LC-MS, FIA-MS And MS-MS"
Trends Anal. Chem. 1996 Volume 15, Issue 8 Pages 349-362
H. Fr. Schr&ouml;der

Abstract: Various analytical methods for the determination of organic pollutants from textile waste waters and their behavior towards physical, chemical and biochemical treatments are considered. Specific MS procedures are presented for the characterization of non-degradable compounds and their reaction products after physico-chemical and biochemical treatment. No elimination was observed using biochemical and adsorptive procedures and there were insufficient results from physico-chemical treatments.
Toxins HPLC Mass spectrometry

"Surface Enhanced Raman Spectroscopy Using Metallic Nanostructures"
Trends Anal. Chem. 1998 Volume 17, Issue 8-9 Pages 557-582
Tuan Vo-Dinh

Abstract: This article provides an overview of the development and application of the surface-enhanced Raman scattering (SERS) techniques using metal-coated nanostructures on solid substrates, An introduction to theoretical principles of the SERS effect and the different SERS-active media is presented. The focus is on nanostructured solid substrates and their practical applications in chemical, environmental and biomedical areas. Specific examples of analytical techniques, instruments and sensors developed in the author's laboratory will be discussed to illustrate the usefulness and potential of the SERS techniques.
Raman Apparatus Instrumentation Review

"Potentials Of Multisyringe Flow Injection Analysis For Chemiluminescence Detection"
Anal. Chim. Acta 2005 Volume 541, Issue 1-2 Pages 55-66
Manuel Mir&oacute;, Jos&eacute; Manuel Estela and V&iacute;ctor Cerd&agrave;

Abstract: In this paper, multisyringe flow injection analysis (MSFIA) is presented as a powerful and promising tool for automated liquid-phase chemiluminescence (CL) assays. The capability of operation under discontinuous forward flow regime while handling minute, well-defined volumes of sample and reagents in a multicommuted format offers unrivalled analytical features. As opposed to the parent flow injection (FI) and sequential injection (SI) analysis, CL reactions with divergent pH and kinetic demands can be easily implemented in a single protocol sequence, as demonstrated in the bulk of the text via luminol-based methods. MSFIA is proven extremely suitable for accommodating enzymatic CL assays in a renewable fashion by exploiting soluble enzymes, with no need for the typical immobilization procedures used in FI and SI systems. Solid-phase CL sensors have also gained full advantage of the benefits of MSFIA. In this context, a novel optosensor devised for on-line monitoring of trace levels of orthophosphate is described. Similar configurations are proposed for the selective and sensitive determination of metals, Vitamins, nutrients and saccharides in environmental and biological samples as well as beverages, which denotes the versatility of this automated flow technique. Special emphasis is also given to the simple instrumental set-up, including a dedicated flow-through luminometer, arranged for a multitude of CL assays.
Cobalt(II) Hydrogen peroxide Phosphate Chemiluminescence Multisyringe Automation Review Multiinjection

"Electrochemiluminescent Analysis: Advances, Problems And Prospects"
J. Anal. Chem. 1994 Volume 49, Issue 9 Pages 920-925
Rozhitskii, N.N.;Belash, E.M.;Bykh, A.I.

Abstract: A review is presented of the application of electrochemical luminescence analysis for the determination of organic compounds in environmental samples, for medical-biological research and for controlling organic syntheses. Some typical applications are illustrated. The use of the technique in conjunction with HPLC and PIA procedures is mentioned. (58 references).
Chemiluminescence HPLC Review

"Voltammetric Detection In Flow Injection Analysis Using Electrocatalytic Systems"
J. Anal. Chem. 1996 Volume 51, Issue 2 Pages 143-148
G. K. Budnikov

Abstract: The application of FIA to environmental, clinical and biological analysis is reviewed. (26 references). Specific features, the field of application, and restrictions of voltammetric detection in flow-injection analysis are considered. The typical examples illustrating advances in this promising direction are given.
Voltammetry Review

"Flow Injection Determination Of Sulfur Dioxide In Air With Chromatomembrane Preconcentration"
J. Anal. Chem. 1996 Volume 51, Issue 8 Pages 820-823
L. N. Moskvin and V. V. Nikonorov

Abstract: A gaseous sample containing SO2 was passed through a chromatoconcentrator and the concentrated SO2 was absorbed in a solution of iodine in KI containing starch. The absorbance of the sorbent was determined with a flow-through photometric cell at 597 nm. The concentrator incorporated a porous PTFE membrane with 0.3-0.5 µm micropores and 100-200 µm macropores. The sorbent was a filtered solution containing 47.5 µM-I2, 0.01 M KI and 0.03% starch. The gas flow was 50 ml/min and the sorbent flow was 0.3 ml/min. The limit of detection of SO2 in the sorbent was 2 µM. Interference caused by H2S, CH3SH, (CH3)2S and NOx was similar to that found with other analytical methods.
Sulfur dioxide Spectrophotometry Chromatomembrane Interferences Teflon membrane Solid phase reagent Preconcentration

"Reversed Flow Injection Spectrophotometric Monitoring Of Dissolved Oxygen In Water"
J. Anal. Chem. 1996 Volume 51, Issue 10 Pages 993-998
V. V. Kuznetsov and M. V. Murasheva

Abstract: The method is based on the oxidation of the leuco-form of methylene blue by the dissolved O2 as monitored by stopped-flow reversed FIA. The leuco-form was prepared by the reduction of 0.1 M methylene blue in deaerated water with a 1:1.1 molar mixture of 0.025 M FeSO4 and 0.025 M EDTA. The sample was pumped at 10 ml/min through the measuring cell (0.2 ml) for 50 s periods, interrupted by 20 s intervals. The leuco-methylene blue solution (0.1 ml) was injected into the sample stream over a 3 s period, and the absorbance was measured at 620 nm. The limit of detection was ~0.02 mg/l and the RSD were 1-5%.
Oxygen Spectrophotometry Reverse Stopped-flow

"Determination Of Toxic Substances Based On Enzyme Inhibition. Part II. Electrochemical Biosensors For The Determination Of Pesticides Using Flow Systems"
Crit. Rev. Anal. Chem. 2003 Volume 33, Issue 2 Pages 127-143
S&iacute;lvia Sol&eacute;, Arben Merko&ccedil;i and Salvador Alegret

Abstract: Enzyme inhibition coupled to flow injection systems set-ups are a powerful tool for the monitoring of environmental toxics. The present review examines the latest contributions to this field where electrochemical detection is used. The advantages and limitations of the FIA technique in the context of enzyme inhibition analytical procedures are discussed. The present review is organized in accordance to the enzyme (cholinesterases, tyrosinases, or alkaline phosphatase) used in the measurement.
Enzymes Sensor Review

"Flow Injection Methods Of Analysis For Waters. II. Organic Pollutants"
Crit. Rev. Anal. Chem. 2003 Volume 33, Issue 1 Pages 57-68
Andrei F. Dunec, Mihaela Cheregi, Jose Martinez Calatayud, Jose Vicente Garcia Mateo and Hassan Y. Aboul Enein

Abstract: A comprehensive, critical and updated review for the applications of flow-injection analysis (FIA) techniques for the analysis of organic pollutants in several types of water samples, except marine waters, is presented. The methods of indirect determination of organic pollutants in water by using flow injection coupled with atomic absorption spectroscopy are also discussed.
Spectrophotometry Review

"An Automated Sampler For Collection Of Atmospheric Trace Gas Samples For Stable Isotope Analyses"
Agric. For. Meteorol. 2003 Volume 118, Issue 1-2 Pages 113-124
A. J. Schauer, C. -T. Lai, D. R. Bowling and J. R. Ehleringer

Abstract: Research focused on the isotopic composition of CO2 exchange between terrestrial ecosystems and the atmosphere has been historically constrained by the need for personnel to be present at remote field sites for sample collection. In practice, this has limited sampling frequency and duration, and potentially even biases sampling events to fair weather periods. We have developed an automated sampling system that can be installed and used for unattended collection of 100 mL air samples in remote areas. The sampler was designed with the primary goal of collecting samples for analysis of CO2 concentration and its isotopic composition in ecosystem-atmosphere flux research, but several other potential applications are also discussed.Laboratory tests examined potential artifacts associated with sampler components. These tests included evaluation of potential isotopic exchange between atmospheric CO2 and sampler component materials and the effects of sample exposure to these materials for up to 5 days and under a wide range of temperatures (10-50°C). Some of the rejected component materials influenced either CO2 mole fraction or CO2 isotopic content. Exposure of air at subambient CO2 concentrations to all sampler components in an intact system for 5 days resulted in a [CO2] value that was 0.9 µmol mol-1 higher than for an equivalent sample collected by the sampler but not stored. Associated exposure-induced errors in δ13C of CO2 were generally small, ranging between 0.03 and 0.17[permil] for 0 day versus 5 days exposure, respectively. These error values were within the sampling precision associated with a PreCon continuous flow mass spectrometer analysis. A more substantial exposure-induced error was observed for δ18O in CO2 (0.29 and 0.88[permil], respectively). The potential for isotopic exchange between CO2 and sampler components increased under a combination of elevated temperature and multiple-day storage treatments. These errors were small and of similar magnitude between 10 and 40°C, but unacceptably large at 50°C. Finally, we compared Keeling plots created with samples collected by the sampler with those collected simultaneously by a manual method and found no detectable differences between the two approaches. Based on these results, we conclude that sampler induced isotopic exchange for air samples held up to 5 days between 10 and 40°C is largely within the overall precision limits of a PreCon continuous flow mass spectrometer measurement.
Carbon dioxide Mass spectrometry Isotope ratio Apparatus Optimization Gas phase detection

"Graphite Furnace Atomic Absorption Spectrometric Determination Of Rhodium After Online Ion-Exchange Preconcentration"
Anal. Lett. 2004 Volume 37, Issue 13 Pages 2685-2700
Fuensanta S&aacute;nchez Rojas, Catalina Bosch Ojeda, Jos&eacute; M. Cano Pav&oacute;n

Abstract: A method for the determination of rhodium in different samples at trace levels is presented. The investigated metal is pre-concentrated on a chelating resin microcolumn [1,5-Bis(2-pyridyl)-3-sulphophenyl methylene thiocarbonohydarzide (PSTH) immobilized on an anion-exchange resin (Dowex 1x 8-200)] placed in the autosampler arm. The modification of the autosampler in the tubing line and circuit allowed either the flow of the sample through the column or the operation of the autosampler in the normal mode, where microlitres of 4 M HNO 3, which acts as the elution agent, pass through the microcolumn eluting Rh(III), which is directly deposited in the graphite tube as a drop of a precisely defined volume. The detection limit is 0.3 ng mL -;1. Linearity is maintained in the concentration range 0-50 ng mL -;1 for rhodium, with correlation factor of 0.999 and relative standard deviation of 1.8% for 10 ng mL -;1 of Rh. The effects of various parameters such as pH, concentration and volume of eluent, sample loading time, sample flow rate, and interference of a large number of metal ions and anions on the determination of this metal was studied in detail to optimize the conditions for their determination in various samples. The method is found to be highly selective, fairly sensitive, simple, rapid and economical, and may be safely applied to their determination in different complex materials, such as environmental samples and catalysts.
Rhodium Spectrophotometry Preconcentration Column Dowex Optimization Interferences

"Automatic Pre-concentration And Treatment For The Analysis Of Environmental Samples Using Non-chromatographic Flow Techniques"
Int. J. Environ. Anal. Chem. 2005 Volume 85, Issue 4-5 Pages 231-253
V&iacute;ctor Cerd&agrave; and Jos&eacute; Manuel Estela

Abstract: In this work a brief description and a comparative review of different non-chromatographic flow analytical methods following their historical evolution are carried out with the aim to assess both the advantages and disadvantages of the methods. In addition, a comparative study of different clean up and pre-concentration techniques used the above methods to achieve the selectivity and sensitivity required in environmental applications, is also carried out. The possibilities offered by commuted flow techniques for the development of expert systems capable of selecting the most adequate procedures regarding the resolution of speciation problems - with or without involving pre-concentration of analytes, are considered. Finally, several existing computer programs are referred to, discussing the advantages of those capable of satisfying the needs of all flow techniques, without requiring a specific program for each case. The above-mentioned developments are illustrated by the description of various analytical methodologies.
Review Preconcentration

"A Sequential Injection Method For Radium Determination In Environmental Samples"
Radioact. Radiochem. 1999 Volume 10, Issue 2 Pages 16-21
Caldes, A.;Gomez, E.;Garcias, F.;Casas, M.;Cerda, V.

Abstract: The authors have developed a semiautomatic procedure for determination of 226Ra in environmental samples. The methodology is based upon automatic isotope separation and pre-concentration using a sequential injection procedure. Once the sample to be analyzed has been prepared, its 226Ra concentration is obtained by means of a low background proportional counter. Before the series reaches the equilibrium the determination can be carried out simultaneously for several samples by using a multiple-sample proportional counter, or consecutively with a simple counter if the function of activity vs. time is known. By using an autosampler, a sampling rate of 3 h-1 with a 40 mL initial sample volume is achieved. This is an important improvement regarding the non-automatic method (0.5 h-1}). The LLD of the procedure is 0.012 Bq with a relative standard deviation of 6.9% (number of samples= 4) for a 226Ra activity of 1.0 Bq/L.
Radium Scintillation counter Radiochemical Sequential injection Preconcentration