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
Website: @unf

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Classification: Water -> industrial

Citations 29

"Polarographic Detection By Reverse-pulse Amperometry In Cation-exchange Chromatography [of Trace Metals In Water] Without Interference From Dissolved Oxygen"
Anal. Chim. Acta 1985 Volume 175, Issue 1 Pages 23-35
Taisung Hsi and Dennis C. Johnson

Abstract: Samples of ground waters were acidified to pH 1.6 and treated with 10% Na acetate and 5% hydroxylammoniun chloride, to reduce Fe(III) to Fe(II). Power-plant water samples were pre-concentrated with use of a Dowex 50W-X8 cation-exchange column. Filtered aliquots (100 µL) were then injected on to a column (5 cm x 4 mm) packed with Durrum DC-4A sulfonated cation-exchange resin, with 0.25 M Na H tartrate - 0.06 M Mg(II) at pH 3.8 as mobile phase (0.62 mL min-1). Polarographic flow injection detection of Cu(II), Zn(II), Ni(II), Pb(II), Cd(II) and Fe(II) was carried out with use of a static dropping-mercury electrode at +0.20 V vs. the SCE. Rectilinear calibration graphs were obtained for all cations. Detection limits in ground-water samples were 64 µg L-1 (Cu(II)), 13 µg L-1 (Zn(II)), 120 µg l-1(Ni(II)), 83 µg L-1 (Pb(II)), 56 µg L-1 (Cd(II)) and 100 µg L-1 (Fe(II)); pre-concentration improved these limits ~100-fold. Removal of dissolved O was not needed because the anodic signals for oxidation of the reduction products were measured at a potential at which O was not electroactive.
Cadmium(2+) Copper(II) Iron(2+) Lead(2+) Nickel(II) Zinc(II) Amperometry HPIC Electrode Polarography Interferences Dowex Preconcentration Resin

"Flow Injection Analysis In Online Process Control"
Anal. Chim. Acta 1986 Volume 179, Issue 1 Pages 91-101
W. E. Van Der Linden

Abstract: A review is presented, with 20 references. Examples of industrial applications are limited to the field of water quality surveillance.
Sulfide Process control Review

"Applications Of Flow Injection Analysis In A Power Plant Determination Of PH, Ammonia And Hydrazine In An AVT-conditioned Water Steam Cycle"
Anal. Chim. Acta 1988 Volume 214, Issue 1-2 Pages 367-374
M. L. Balconi and F. Sigon, R. Ferraroli, F. Realini

Abstract: A simple dual channel manifold was used for pH measurement (20-cm reaction coil) and for determination of hydrazine(I) (100-cm coil). For determination of NH3, the sample was injected into the water carrier which flowed directly to the flow-through cell containing an NH4+-selective electrode and a Ag - AgCl reference electrode. For pH measurement, sample solution (100 µL) was injected into the water carrier stream which merged with an ionic-strength buffer solution (0.02 M KCl) before passing to a flow-through cell containing a combined glass electrode. For determination of I, the reagent solution was 3 mM KI - 1 M acetic acid - 4.7 mM KIO3 - water and a residual Cl sensor containing a double electrode system was used. The methods were suitable for measurement of pH in the range 4.5 to 9.5 and for determination of 0.25 to 2 mg L-1 of NH3-N and 50 to 300 µg L-1 of I-N in a water - steam cycle. Good results were achieved for pH and NH3 measurements in terms of application range and frequency of analysis. A 'measurability' model for data evaluation is proposed.
Ammonia Hydrazine pH Electrode Electrode Electrode Electrode Merging zones

"Rapid Spectrophotometric Determination Of Total Phosphorus In Industrial Wastewaters By Flow Injection Analysis Including A Capillary Digestor"
Anal. Chim. Acta 1988 Volume 214, Issue 1-2 Pages 229-237
M. Aoyagi, Y. Yasumasa and A. Nishida

Abstract: Sample solution in water (as carrier) merged with oxidizing agent (K2S2O8 in H2O) before passing to a digestion unit consisting of 10 m of PTFE tubing holding 10 m of platinum wire (0.2 mm diameter) wound round an aluminum bobbin and heated to 160°C. The solution then mixed sequentially with reducing agent (aqueous 5% Na2S2O3) and color-forming reagent [aqueous malachite green (C. I. Basic Green 4) and (NH4)6Mo7O24.4H2O in ~15% H2SO4] and the absorbance was measured at 650 nm. Calibration graphs were rectilinear for up to 500 ng mL-1 of P and the determination limit was 2 ng mL-1. The coefficient of variation (n = 5) at 200 and 2 ng mL-1 were 0.3 and 6.0%, respectively. Recoveries were quantitative. The method was applied to determine P in industrial waste water and seawater; results agreed with those from the standard procedure.
Phosphorus Spectrophotometry Sample preparation Calibration Catalysis Online digestion Heated reaction Standard method

"Determination Of Ultratrace Levels Of Cobalt By Ion-chromatographic Separation And Chemiluminescence Detection"
Anal. Chim. Acta 1989 Volume 221, Issue 2 Pages 249-258
Hiroyuki Sakai, Terufumi Fujiwara, Manabu Yamamoto and Takahiro Kumamaru

Abstract: Separation from interfering components was carried out on a TSK gel IC-Cation-SW column (5 cm x 4.6 mm); the column was attached to a flow injection analyzer., with 3 mM BaCl2 adjusted to pH 3 with dilute HCl as the mobile phase (1 mL min-1). The column eluate was mixed with the reagent stream, consisting of a mixture of aqueous 20 mM H2O2 and 1 mM luminol in 20 mM NaOH (each 0.5 mL min-1). The chemiluminescence of the final mixture was measured and the effect of pH on its intensity was investigated. The detection limit was 1 pg mL-1 of Co; calibration graphs were rectilinear from 10 pg mL-1 over six orders of magnitude. The method was applied in the analysis of the primary coolant of a boiling-water reactor and commercially prepared copper standard solution intended for use in AAS determinations.
Cobalt Chemiluminescence Post-column derivatization Interferences Ultratrace

"Flow Injection Analysis For Power Plants: Evaluation Of Detectors For The Determination Of Control Parameters In Conditioned Water-steam Cycles"
Anal. Chim. Acta 1990 Volume 234, Issue 1 Pages 167-173
M. L. Balconi and F. Sigon, M. Borgarello and R. Ferraroli, F. Realini

Abstract: Flow injection methods are presented for the analysis of power plant water. Methods involve various spectrophotometric reagents, gas diffusion, ion-selective and other electrodes, and biamperometry. Analytes include NH3, hydrazine, Cu, Fe and Si, and pH is also measured. Reagents, flow manifolds and detectors are presented for each method. The range of application, coefficient of variation and sampling rate are tabulated for each method, and results are discussed.
Ammonia Hydrazine Copper Iron Silicon pH Biamperometry Spectrophotometry Electrode Electrode Gas diffusion

"Determination Of Nanoequivalent Amounts Of Organic Halogens By Sample Combustion-flow Injection Conductimetry With Online Preconcentration"
Anal. Chim. Acta 1990 Volume 241, Issue 1 Pages 71-82
I. Gács and K. Payer

Abstract: The sample was heated at 950°C in a stream of O2 and the decomposition products containing halogens were absorbed in a capillary denuder tube coated with an aqueous solution of a hydrazine monohydrohalide. The hydrohalic acid formed in the liquid film was eluted with a solution of the absorbant to a conductivity microdetector where the change in specific conductance due to the acid was rectilinearly related to the halogen content. The method was tested with 14 compounds and was applied to the analysis of river and drinking water and to industrial atmospheres. The limit of detection for the volatile organic halogen content in water was 0.01 µg L-1 and 0.2 µg m-3 for the total organic halogen content in air. For 3 to 100 nanoequivalents of Cl, the precision (95% confidence limits) (n = 5) was 5%.
Organic, halogenated Conductometry Detector Detection limit Preconcentration

"Spectrophotometric Determination Of Calcium In Paper Machine White Water By Sequential Injection Analysis"
Anal. Chim. Acta 1995 Volume 308, Issue 1-3 Pages 286-292
Johan Nyman and Ari Ivaska*

Abstract: The determination of Ca in white water of a paper machine was based on the formation of the colored complex between Ca2+ and o-cresolphthalein complexone (CPC). White water samples were centrifuged at 1500 rpm for 30 min and the clear supernatant solution was used for the Ca2+ determination. The analysis was carried out on a computer-controlled sequential analysis system comprising of a peristaltic pump, a 10 port multi-position valve, a holding coil (1.5 m x 0.9 mm i.d.), a reaction coil (60 cm x 0.5 mm i.d.) and a spectrophotometric detector equipped with a sandwich-type flow-through cell (30 µL; 3 mm light path). The detection wavelength was 580 nm and flow-rates of 3.3-3.5 ml/min were used. The analysis was carried out by aspirating sample solution from the holding coil for 0.5 s (30 µL) followed by 2.5 mg/ml 8-hydroxquinoline solution for 1 s (60 µL) and 0.24 mM CPC for 1 s (60 µL). The mixture was pumped through the detection cell. The calibration graph was linear for 10^-500 mg/l Ca and the RSD (n = 5) was 2.5% within the linear range.
Calcium Spectrophotometry Sequential injection Complexation Computer

"Speciation Of Metals In Solution By Flow Injection Analysis. 1. Sequential Spectrophotometric And Atomic Absorption Detectors"
Analyst 1984 Volume 109, Issue 7 Pages 839-842
Thomas P. Lynch, Nicholas J. Kernoghan and John N. Wilson

Abstract: Application of the technique is exemplified by the determination of(I) Cr(VI) and total Cr in seawater, and(II) Fe(II) and total Fe in mineral process solution In(I), Cr(VI) is determined spectrophotometrically at 540 nm with 1,5-diphenylcarbazide by a modification of the procedure of Joergensen and Regitano (cf. Anal. Abstr., 1980, 39, 4G17). Then total Cr is determined in the flow stream by AAS at 357.9 nm in an air - acetylene flame. For 30 µL samples, calibration graphs are rectilinear for 20 ppm of Cr(VI) and 50 ppm of total Cr. For 16 ppm of total Cr and 8 ppm of Cr(VI), the coefficient of variation are 1.5%. Results on 4 samples of seawater for total Cr agreed with those obtained by AAS In(II), Fe(II) is determined spectrophotometrically at 508 nm with 1,10-phenanthroline and total Fe is determined by AAS at 248.3 nm in an air - acetylene flame. With 20 µL samples, calibration graphs are rectilinear for 120 ppm of Fe(II) or total Fe. For 40 ppm of total Fe and 20 ppm of Fe(II), the coefficient of variation are 1.8 and 0.7%, respectively. In the determination of Fe(II) there is no interference from 25 ppm of Bi, 50 ppm of Mo, 120 ppm of Hg(II) or Co(II) and 200 ppm of Cu(II). With both systems, sampling rates of up to 120 h-1 are possible.
Chromium, total Chromium(VI) Iron(2+) Iron Spectrophotometry Spectrophotometry Interferences Process control Speciation

"Speciation Of Metals In Solution By Flow Injection Analysis. 2. Determination Of Iron(III) And Iron(II) In Mineral Process Liquors By Simultaneous Injection Into Parallel Streams"
Analyst 1984 Volume 109, Issue 7 Pages 843-846
Thomas P. Lynch, Nicholas J. Kernoghan and John N. Wilson

Abstract: Two parallel streams, with simultaneous sample introduction by coupled synchronized injection valves, are analyzed colorimetrically. Bivalent Fe is determined as its 1,10-phenanthroline complex at 508 nm and Fe(III) as its complex with SCN- at 475 nm. With 20 µL samples, the working ranges are 0.5 to 180 ppm and 0.5 to 120 ppm for Fe(III) and Fe(II), respectively, although in each instance the calibration graphs are curvilinear. For max. stability, samples and standard solution should be prepared in aqueous 1% (v/v) HCl. Tolerance limits are listed for 19 species. A novel application is described of the simplex optimization procedure in minimizing the interference of Cu(II) in the determination of Fe(III). For 80 ppm each of Fe(II) and Fe(III), the coefficient of variation are 0.56 and 0.81%, respectively (n = 40). Results are presented for Fe(II) and Fe(III) in HCl extracts of three geological samples. The sampling rate is 120 h-1. (For Part I see Anal. Abstr., 1985, 47, 2H51).
Iron(2+) Iron(III) Sample preparation Spectrophotometry Process control Simplex Optimization Interferences Speciation

"Spectrophotometric Determination Of Iron In Boiler And Well Waters By Flow Injection Analysis Using 2-nitroso-5-(N-propyl-N-sulfopropylamino)phenol"
Analyst 1987 Volume 112, Issue 8 Pages 1127-1130
Noriko Ohno and Tadao Sakai

Abstract: A flow injection system is described in which Fe is determined spectrophotometrically at 753 nm with the cited reagent in phosphate buffer medium (pH 8.0) and in the presence of Na ascorbate to reduce Fe(III). The analytical range is 4 to 100 µg l-1, the detection limit is 1 µg L-1 and the sampling rate is 25 h-1. Nickel, Co, Cu, Zn and Cd at the 500 µg L-1 level do not interfere. The average recovery error is ±1%. The results obtained agree well with those obtained by using 2,4,6-tri-2-pyridyl-1,3,5-triazine. A flow injection system is described in which Fe is determined spectrophotometrically at 753 nm with the cited reagent in phosphate buffer medium (pH 8.0) and in the presence of Na ascorbate to reduce Fe(III). The analytical range is 4 to 100 µg l-1, the detection limit is 1 µg L-1 and the sampling rate is 25 h-1. Nickel, Co, Cu, Zn and Cd at the 500 µg L-1 level do not interfere. The average recovery error is ±1%. The results obtained agree well with those obtained by using 2,4,6-tri-2-pyridyl-1,3,5-triazine.
Iron Spectrophotometry Interferences Method comparison

"Trace Enrichment And Determination Of Sulfate By Flow Injection Inductively Coupled Plasma Atomic Emission Spectrometry"
J. Anal. At. Spectrom. 1987 Volume 2, Issue 6 Pages 553-555
Alan G. Cox, Cameron W. McLeod, Douglas L. Miles and Jennifer M. Cook

Abstract: The sample was injected into a stream of 0.01 M HNO3, and SO42- was retained on a column (2.5 cm x 1.5 mm) of acidic alumina, from which it was eluted by injection of 0.2 mL of aqueous 2 M NH3, and carried to the ICP for determination at 180.73 nm. Residual SO42- was eluted with further NH3, and the recovery was calculated as the ratio of peak areas for replicate injections of SO42- solution with and without the alumina column in the stream. The calibration graph was rectilinear for up to 1 mg L-1 of SO42- (2 mL injections), the detection limit was 2.8 µg l-1, and the coefficient of variation (n = 7) at 10 µg L-1 and 1 mg L-1 were 7 and 0.8%, respectively. The method was applied to various natural waters (seawater was diluted two-hundredfold), with results in good agreement with those by conventional ICP-AES. The method was also applied to boiler-feed water.
Sulfate Spectrophotometry Alumina Column Preconcentration Method comparison

"Automated System For Total Phosphorus In Wastewaters By Flow Injection Analysis"
Bunseki Kagaku 1984 Volume 33, Issue 12 Pages 683-686
Korenaga, T.;Okada, K.

Abstract: A 0.31 mL sample is injected into a stream (1.2 mL min-1) of S2O82- solution, which then passes through a heating coil at 120°C before merging with a stream (0.2 mL min-1) of acidic molybdate solution The stream passes through a further heating coil at 75°C, and its absorbance is monitored at 880 nm. The response is rectilinear for up to 10 mg L-1 of P, the limit of detection is 0.01 mg l-1, and the sampling rate is 10 h-1. The coefficient of variation (n = 10) ranged from 0.3 to 1%. Results for various effluents agreed with those by the conventional manual method.
Phosphorus Spectrophotometry Heated reaction

"Continuous Monitoring Method Of Trace Silicon In Industrial Water Using Continuous Micro Flow-analysis"
Bunseki Kagaku 1989 Volume 38, Issue 9 Pages 419-423
Goto, M.;Hu, W.Z.;Ishii, D.

Abstract: The sample - molybdic acid reagent mixture is introduced into a PTFE reaction tube (8 m x 0.5 mm) at 23°C. A platinum wire (0.2 mm diameter) assists mixing. The stream from the reaction tube is mixed with a stream of reducing reagent to form molybdenum blue. The absorbance is measured at 815 nm. From 2 to 2000 ppb of Si could be determined.
Silicon Spectrophotometry

"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

"Determination Of Trace Concentrations Of Copper By FIA Flame AAS After Preconcentration On Chelating Sorbents"
Collect. Czech. Chem. Commun. 1989 Volume 54, Issue 7 Pages 1785-1794
Kuban, V.;Komarek, J.;Zdrahal, Z.

Abstract: Details are given of a comparison of Spheron Oxin 1000 [63 to 100 µm; containing bonded quinolin-8-ol (I)], Ostsorb Oxin (0.1 to 0.5 mm; containing bonded I) and Ostsorb DTTA (0.1 to 0.5 mm; containing bonded diethylenetriaminepenta-acetic acid) for the chelating flow injection pre-concentration. of Cu before AAS determination with an air - acetylene flame. Breakthrough capacities, enrichment factors and elution and sorption efficiencies were among the parameters studied, and relative merits of the three sorbents are discussed. By sorption from 2 mM acetate buffer medium of pH 4.2 and desorption with 2 M HCl, up to 100, 150 or 200 ppb of Cu could be determined with the respective sorbents; a limit of determination of 0.3 ppb was attainable. The technique gave similar efficiency to electrothermal AAS, and sampling rates up to 70 h-1 could be used. A column of Spheron Oxin 1000 was used in the determination of Cu in high-purity power station cooling water.
Copper Spectrophotometry Chelation Buffer PPB Column Method comparison Preconcentration 8-Hydroxyquinoline

"Determination Of Copper By Flow Injection Analysis With Flame AAS Detection After Preconcentration By Solvent Extraction"
Collect. Czech. Chem. Commun. 1989 Volume 54, Issue 10 Pages 2683-2691
Kuban, V.;Komarek, J.;Cajkova, D.

Abstract: In the flow injection manifold described, sample solution in 0.2 M acetate buffer (pH 5.05) is mixed with aqueous 0.1% ammonium pyrrolidine-1-carbodithioate, the Cu chelate is extracted into isobutyl methyl ketone, and portions of the organic phase, after passage through a phase separator, are aspirated into an air - acetylene flame for determination of Cu at 324.8 nm. The calibration graph is rectilinear for 20 for 900 or 2 to 500 ng mL-1 for 100- or 150 µL injections, respectively. Recoveries were quantitative. About 40 samples h-1 can be analyzed. The method was applied to water from power station cooling circuits.
Copper Spectrophotometry Sample preparation Buffer Chelation Phase separator MIBK Organic phase detection Preconcentration Solvent extraction

"Continuous-flow Method For Simultaneous Determination Of Monochloramine, Dichloramine, And Free Chlorine: Application To A Water Purification Plant"
Environ. Sci. Technol. 1989 Volume 23, Issue 1 Pages 46-50
Toyoaki Aoki

Abstract: A continuous-flow system is described and illustrated, for simultaneous determination of chloramide (I), chlorimide (II) and free Cl in water, which incorporates three double-tube separation units, each consisting of a PTFE outer tube and an inner tube of micro-porous PTFE. The three tubes were used for determination of I, I plus II, and I, II and Cl, respectively, by reaction with I- and absorbance measurement at 288 nm. Optimum pH and reagent concentration. for each reaction are given. Calibration graphs covered the ranges from 0.1, 0.02 and 0.02 mg L-1 of Cl for I, II and free Cl, respectively, to 71 mg L-1 for all Cl species. Within- and between-run coefficient of variation were 3.3% (n = 5) and 10% (n = 8), respectively. The method was applied in monitoring of I and II in water purification plants.
Chloramide Chlorimide Chlorine, free Spectrophotometry pH Tubular membrane Simultaneous analysis

"Rapid Distillationless 'Free Cyanide' Determination By A Flow Injection Ligand Exchange Method"
Environ. Sci. Technol. 1995 Volume 29, Issue 2 Pages 426-430
Emil B. Milosavljevic, Ljiljana Solujic, and James L. Hendrix

Abstract: Sample solution was injected into a carrier solution (1 ml/min) of 0.2 M HCl. the carrier stream merged with a reagent stream (1 ml/min) of 0.2 M HCl, passed through a mixing coil (30 cm x 0.5 mm i.d.) and into a diffusion cell with an acceptor solution 92 ml/min) of 0.01 M NaOH. The resulting solution went into a thin layer flow-through amperometric cell comprising a Ag working and Pt counter electrode with a Ag/AgCl reference electrode separated from the flowing stream by an ion exchange Nafion membrane. The cell was potentiostated and the current measured by a pulsed amperometric detector. The dynamic range of the FIA system was 0.001-5 µg/ml and recoveries of cyanide from all metal cyano complexes that produce free cyanides were 97.4-104.3% with RSD of 0.2-1.3% for 0.2 µg/ml cyanide and 98-103% with RSD of 0.2-0.7% for 2 µ/ml cyanide. The method was used to determine cyanide in industrial process waters. In the first part of this research, extensive species-dependent cyanide recoveries studies were performed using the approved standard methods available for determination of free cyanide. The data obtained show that serious problems are associated with both the CATC (cyanide amenable to chlorination) and WAD (weak and dissociable cyanide) methods. In the second part, a novel flow injection gas diffusion method for the determination of free cyanide was developed. Complete cyanide recoveries even in the presence of a large excess of the free CN- ion were found for the following species: 2-, 2-, 2-, 3-, -, 2-, and Hg(CN)2. No recoveries of CN- were obtained from the species that are considered as non free cyanide producing ones, such as 3-/4-, 3-, and -. The method developed is rapid, selective, reproducible, and easy to automate. Copyright 1995, American Chemical Society.
Cyanide, free Amperometry Electrode Interferences Process control Gas diffusion Nafion membrane Standard method Method comparison

"Method Comparison And Evaluation For The Analysis Of Weak Acid-dissociable Cyanide"
Environ. Sci. Technol. 1997 Volume 31, Issue 1 Pages 52-57
John R. Sebroski and Richard H. Ode

Abstract: This study compared and evaluated three methods to determine weak acid-dissociable cyanide. An emphasis was placed on data quality using a performance-based approach to overcome the problems associated with cyanide analyzes. The three methods compared were Standard Methods, 18th ed., Method 4500 CN- l (macro distillation, colorimetric finish); Bayer Method SA-61A (steam distillation at pH 4.5, ion selective electrode finish); and Bayer Method SA-100 (FlA or flow injection analysis, gas diffusion separation, and amperometric detection). The study demonstrated method detection limits, recoveries of cyanide species, and use of ligand exchange reagents to improve selected cyanide species recoveries. Potential interferences were examined with the FIA procedure to demonstrate that the method would be applicable to industrial wastewater samples subject to NPDES regulations. This performance-based approach led to a successful means to measure weak acid-dissociable cyanide in an industrial effluent where other approved methods have failed.
Cyanide Amperometry Electrode Gas diffusion Method comparison Standard method Interferences

"Study And Application Of An Online Flow Injection System"
Fenxi Shiyanshi 1990 Volume 9, Issue 6 Pages 31-33
Zhang Haiping, Pan Hongze and Cheng Weicai

Abstract: A double-pump confluence hydrodynamic injection technique is proposed and the performance and characteristics of the online flow injection analysis system are discussed. The system was applied in the determination of PO43-, hydrazine and SiO32- in power plant water (diagrams given and optimum conditions tabulated). The system can be used to determine 25 ppm of PO43-, 0.01 to 0.4 ppm of hydrazine and 2 ppm of SiO32- with coefficient of variation of 1, 1 and 2%, respectively.
Hydrodynamic injection Optimization

"Simultaneous Determination Of Phosphate And Silicate In Boiler Water From Power-plants With Reversed Flow Injection Spectrophotometry"
Fenxi Shiyanshi 1991 Volume 10, Issue 2 Pages 41-44
Li Yongsheng

Abstract: The cited determination was carried out with use of a dual-circuit flow injection apparatus (diagram given). The reaction for determination of phosphate is carried out in one circuit, that for silicate in the other. The molybdophosphate blue (I) and molybdosilicate blue (II) formed are detected spectrophotometrically, I reaching the detector before II. No interference was observed from Cu(II), Fe(II) or Na; phosphate and silicate did not interfere with determination of the other. Calibration graphs were rectilinear from 2.0 to 24 ppm of phosphate and 0.05 to 6.0 ppm of silicate; coefficient of variation were 1% and recoveries were 96.2 to 103.5%. Sample throughput was ~60 h-1.
Phosphate Silicate Spectrophotometry Interferences Reverse

"Automatic Analytical Methods For Monitoring Water-quality At Power-plants With Reversed Flow Injection Analysis"
Lab. Rob. Autom. 1995 Volume 7, Issue 5 Pages 229-238
Li, Y.S.;Wang, Z.J.

Abstract: The quality of the water at power plants has a direct and substantial impact on safe, efficient, and economical operation of the boilers and turbines; consequently, it is being monitored with online or off-line methods at all power plants throughout the world. However, the analytical methods now being employed are based on the principle of an equilibrium of chemical reactions. As a result, undercertain conditions they either are not suitable for rapidly monitoring use because of the limited speed at which analyzes can be performed, or unacceptable lags can occur before the results of an analysis are known. To overcome the drawbacks and compensate for the deficiencies of the online analyzers now being used, the authors have con ducted an attempt to apply rFIA to online monitoring and analysis of the water at power plants. (28 References)
Reverse Process control

"Flow Injection Atomic Absorption Spectrometry System For Mercury Determination In Water"
Lab. Rob. Autom. 1998 Volume 10, Issue 6 Pages 355-359
Andrei F. Danet, Emilian Georgescu, Mihaela Chergi, Daniela Hiliu

Abstract: A homemade FIA device for Hg determination in water is presented, as well as the influence of different operation parameters. The method is based upon the Hg(II) ion reduction with SnCl2 to elementary Hg, followed by the extraction of the latter from the liquid phase by an air flow, the Hg vapor then being passed into the flow cell of an atomic absorption spectrometer. The measurement sensitivity is good as the method allows for analyzes within 0.01-1 µg Hg2+ mL-1 concentration. range. The time required for one determination is ~2 min as a function of the injected sample volume with an excellent reproducibility of the determinations and a relative standard deviation of 1.02%. This FIA device for Hg2+ determination was successfully employed for analyzing water samples from chlorosodic industry.
Mercury Spectrophotometry Apparatus

"Determination Of Iron In Water By Flow Injection Analysis"
Lihua Jianyan, Huaxue Fence 1988 Volume 24, Issue 2 Pages 89-90
Yu, Z.;Zhang, N.

Abstract: A 100 µL water sample (industrial or well water) is fed into a flow injection analysis system (flow diagram given) in which Fe is allowed to react with 0.05% 1,10-phenanthroline - 0.2% hydroxylammonium chloride - Na acetate mixed chromogenic solution to form a red chelate in Na acetate - HCl buffer solution (pH 5), and the change in absorbance is measured by using a Model 721 spectrophotometer. The calibration graph is rectilinear up to 4 ppm of Fe. Recovery is 98 to 102% with a coefficient of variation of 1.2%. The detection limit is 0.02 ppm. Most co-existing ions do not interfere. Results compared well with those by manual photometry.
Iron Spectrophotometry Chelation Interferences Method comparison

"Continuous Determination Of Silicate In Boiler Water From A Power Plant By Flow Injection Analysis"
Lihua Jianyan, Huaxue Fence 1990 Volume 26, Issue 1 Pages 41-45
Li, Y.

Abstract: Boiler water is analyzed with use of a T1-721 type flow injection analyzer (diagram given). Silicates in the sample react with 100 µL of 10% ammonium molybdate in a carrier stream of 3% H2SO4 in presence of 8% oxalic acid to suppress interference from PO43-, and with 10% ascorbic acid solution at 30°C; the molybdosilicate blue formed is detected at 780 nm. Recoveries were 99.7 to 100.5% with a coefficient of variation of 1%. From 50 to 6000 ppb of silicate could be determined, with an analysis time of 60 samples h-1.
Silicate Spectrophotometry Interferences PPB

"Flow Injection Turbidimetric Analysis Of Sulfate In Water"
Water SA 1986 Volume 12, Issue 1 Pages 43-50
van Staden JF

Abstract: Three flow injection modifications of the turbidimetric determination of SO42- by precipitation as BaSO4 are described and illustrated. Automated pre-filtration with activated carbon - paper is used for removal of suspended solids, organic substances and color from most samples. Single- and double-channel flow injection systems are suitable for determination of SO42- in heavily colored industrial effluents. For samples with a high SO42- content, automated dialysis provided the best system.
Sulfate Turbidimetry Dialysis Interferences Activated carbon