University of North Florida
Browse the Citations
-OR-

Contact Info

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

View Stuart Chalk's profile on LinkedIn

Arsenic

  • IUPAC Name: arsenic
  • Molecular Formula: As
  • CAS Registry Number: 7440-38-2
  • InChI: InChI=1S/As
  • InChI Key: RQNWIZPPADIBDY-UHFFFAOYSA-N

@ ChemSpider@ NIST@ PubChem

Citations 155

"Incidence Of Transitional Cell Carcinoma And Arsenic In Drinking Water: A Follow-up Study Of 8,102 Residents In An Arseniasis-endemic Area In Northeastern Taiwan"
Am. J. Epidemiol. 2001 Volume 153, Issue 5 Pages 411-418
Hung-Yi Chiou, Shu-Ti Chiou, Yi-Hsiang Hsu, Yi-Li Chou, Chin-Hsiao Tseng, Min-Li Wei, and Chien-Jen Chen

Abstract: A significant association between ingested arsenic and bladder cancer has been reported in an arseniasis-endemic area in southwestern Taiwan, where many households share only a few wells in their villages. In another arseniasis-endemic area in northeastern Taiwan, each household has its own well for obtaining drinking water. In 1991-1994, the authors examined risk of transitional cell carcinoma (TCC) in relation to ingested arsenic in a cohort of 8,102 residents in northeastern Taiwan. Estimation of each study subjects individual exposure to inorganic arsenic was based on the arsenic concentration in his or her own well water, which was determined by hydride generation combined with atomic absorption spectrometry. Information on duration of consumption of the well water was obtained through standardized questionnaire interviews. The occurrence of urinary tract cancers was ascertained by follow-up interview and by data linkage with community hospital records, the national death certification profile, and the cancer registry profile. Cox proportional hazards regression analysis was used to estimate multivariate-adjusted relative risks and 95% confidence intervals. There was a significantly increased incidence of urinary cancers for the study cohort compared with the general population in Taiwan (standardized incidence ratio = 2.05; 95% confidence interval (CI): 1.22, 3.24). A significant dose-response relation between risk of cancers of the urinary organs. especially TCC, and indices of arsenic exposure was observed after adjustment for age, sex, and cigarette smoking. The multivariate-adjusted relative risks of developing TCC were 1.9, 8.2, and 15.3 for arsenic concentrations of 10.1-50.0, 50.1-100, and >100 µg/liter, respectively, compared with the referent level of less than or equal to 10.0 µg/liter.
Water Water Spectrophotometry

"Introduction Of Alcohols In Inductively Coupled Plasma Mass Spectrometry By A Flow Injection System"
Anal. Chim. Acta 1999 Volume 379, Issue 1-2 Pages 175-183
Valderi L. Dressler, Dirce Pozebon and Adilson J. Curtius

Abstract: A flow injection system for the introduction of organic solvents in an instrument of inductively coupled plasma mass spectrometry, using the conventional pneumatic nebulization, is proposed. The instrumental parameters, such as radiofrequency power, nebulization gas flow rate, solution flow rate and time interval between consecutive injections, were optimized for injecting analytical solutions in methanol, ethanol, l-propanol and 1% (v/v) nitric acid in water. In comparison to the conditions for the aqueous solution, a higher power and lower nebulization gas flow rates were adopted for the alcohol solutions. The Ba2+/Ba+ signals ratios are lower in the alcohol solutions, while the CeO+/Ce+ signals ratios are similar in all solvents. The signal intensities for the studied isotopes are enhanced in the organic media, partially due to a criterium used in the optimization, that is, CeO+/Ce+ signal ratio below 3%. The enhancement is specially high for Se, As and Hg. The proposed FIA system, with an injection of a small volume, typically 100 µl, of the organic solvent, on Line diluted 1+1 with water, and the continuous washing with an aqueous solution containing 1% (v/v) nitric acid, between the injections, allows the use of the instrument for more than 200 readings, without reoptimization of the plasma conditions and without visible carbon deposits on the cones. The addition of oxygen to the nebulization gas does not bring a real advantage.
Mass spectrometry Organic solvent Interferences Optimization

"HPLC-HG-AAS And HPLC-ICP-MS For Speciation Of Arsenic And Antimony In Biomonitoring"
Am. Lab. News 2002 Volume 34, Issue 6 Pages 10-14
Krachler, M., Falk, K., and Emons, H.

Abstract: This article presents a comparison of the extractability of As and Sb species from biological matrices as well as two different detection principles that have been coupled on-line with HPLC separation of As and Sb species for the purpose of determining speciation patterns in specimens arising from environmental and human biomonitoring.
Biological HPLC Method comparison Speciation

"Determination Of Arsenic And Vanadium In Airborne Related Reference Materials By Inductively Coupled Plasma-mass Spectrometry"
Anal. Chim. Acta 1999 Volume 392, Issue 2-3 Pages 299-306
Chu-Fang Wang, C. Y. Chang, C. J. Chin and L. C. Men

Abstract: This study investigated sample digestion techniques and instrumental interference in determining As and V in airborne related reference materials using inductively coupled plasma mass spectrometry (ICP-MS). Four reference materials, NIST SRM 1648 urban particulate matter, BCR Reference Material No. 176 city waste incineration ash, NIST SRM 2709 San Joaquin soil, and NIST SRM 1633b coal fly ash were dissolved by acid mixture high-pressure bomb digestion. A HNO3+H2O2+HF mixed acid digestion with a low temperature evaporation procedure is proposed as an effective sample pretreatment method for the determination of As in all samples. The addition of HF is required especially for dissolving geologically originated samples such as soil or dust. It was found that, with the proposed digestion procedure, the determinations of V are still unacceptable for highly chlorinated samples when using quadrupole ICP-MS. It was also proved that sector-field ICP-MS is sufficiently sensitive for the determination of V, and can be utilized as a valid tool to investigate the amount and direction of biased results obtained from ICP-MS.
NIST 1648 BCR 176 NIST 1633 NIST 2709 Mass spectrometry Optimization Interferences Reference material

"Amperometric Flow-through Wire Detector: A Practical Design With High Sensitivity"
Anal. Chim. Acta 1980 Volume 116, Issue 1 Pages 33-39
Jean A. Lown, Ross Koile and Dennis C. Johnson

Abstract: A flow-through detector is described which is easily constructed at low cost for application to flow-injection analysis, liquid chromatography and continuous stream analysis. The platinum wire indicating electrode is stretched through a narrow channel cut in a glass-filled teflon block, which also holds the reference and auxiliary electrodes. The response of the detector to ~10^-5 M iodide and arsenic(III) solutions is compared with theoretical predictions for an annular flow cell under laminar fluid dynamics.
Amperometry HPLC Apparatus

"A Flow Injection/hydride Generation System For The Determination Of Arsenic By Inductively-coupled Plasma Atomic Emission Spectrometry"
Anal. Chim. Acta 1984 Volume 161, Issue 1 Pages 275-283
R. R. Liversage and J. C. Van Loon, J. C. De Andrade

Abstract: After optimizing the concentration. of HCl and NaI in the test solution, the concentration. of NaBH4, sample and reductant volume and flow rate, Ar carrier-gas flow rate and r.f. power, As (10 to 1000 ppb) was determined in NBS orchard leaves, coal fly ash and river sediment and NRCC MESS-1 and BCSS-1 standard reference materials with good accuracy and precision by using an ARL 34000 Quantometer. The coefficient of variation (n = 10) at the 100-ppb level of As was 7.2%, and the detection limit was 1.4 ng for a 0.17 mL sample volume The calibration graph was rectilinear for 0.01 to 1 ppm of As. Cobalt, Ni, Ag, Au, Bi, Te and Sn interfered. About 200 injections h-1 were possible.
NIST 1571 NIST 1633 NIST 1645 NRCC BCSS-1 NRCC MESS-1 River Spectrophotometry Interferences Reference material

"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.
Agricultural Environmental Ion exchange Spectrophotometry Spectrophotometry Spectrophotometry Spectrophotometry Spectrophotometry Review Preconcentration Standard additions calibration

"Selectivity Enhancement By Flow Injection Analysis"
Anal. Chim. Acta 1986 Volume 179, Issue 1 Pages 259-267
G. E. Spacey, D. A. Hollowell, K. G. Miller, M. R. Straka and G. Gordon

Abstract: Flow injection analysis was used to improve the selectivity of several existing methods. By kinetic discrimination, O3 is determined by the decolorization of indigo blue at 600 nm with a coefficient of variation of <1%, and ClO2 is determined by chemiluminescence with luminol, each in the presence of Cl. Chlorate can be determined by its reaction with I- in 12 M HCl, the absorbance being measured at 370 nm. The detection limit is 1 µM and the coefficient of variation are <5%. Chlorite and ClO3- are determined by injecting 12 M HCl in front of the sample and a carrier solution of pH 4.0 after it, thus forming two peaks, the first of which corresponds to total ClO3- and ClO2- and the second to ClO2- only. A dual-phase gas diffusion system for hydride generation provides a significant decrease in interference by transition metals.
Chemiluminescence Spectrophotometry Spectrophotometry Sample preparation Extraction Gas diffusion Interferences Kinetic Selectivity Tecator

"Determination Of Arsenic In Glycerol By Flow Injection Hydride Generation And Inductively Coupled Plasma Atomic-emission Spectrometry"
Anal. Chim. Acta 1986 Volume 184, Issue 1 Pages 205-212
Ngee-Heng Tioh, Yecheskel Israel and Ramon M. Barnes

Abstract: A flow injection system is used to mix glycerol solution, containing 0.12 to 3.0 µg g-1 of As, with 1.1% NaBH4 solution (in 0.2 or 0.5 M NaOH) - 6 M HCl (10:49). The generated AsH3 is removed in a vapor - liquid flow cell and determined directly by ICP-AES at 193.7 nm, with Ar as carrier gas (0.39 l min-1). The calibration graph was rectilinear in the range 0.12 to 3.0 µg mL-1 of As with a coefficient of variation of 1.4%.
Organic compound Spectrophotometry

"Determination Of Arsenic And Selenium In Coal By Continuous-flow Hydride-generation Atomic Absorption Spectrometry And Atomic Fluorescence Spectrometry"
Anal. Chim. Acta 1987 Volume 194, Issue 1 Pages 177-187
Les Ebdon and John R. Wilkinson

Abstract: Powdered coal (0.7 g) was digested with 72% HClO4 with cautious heating (and quenching in iced water if ignition appeared imminent) until all carbonaceous material had dissolved and was then heated under reflux for a further 10 min. After cooling, the solution was transferred, with washing with 5 M HCl, to a 50 mL flask. In order to remove interfering metal ions, portions (10 to 20 ml) of the digest were transferred to a PTFE centrifuge tube and 2 mL of 10% LaCl3 solution was added followed by 1 mL of either 10% NaI solution (for As) or 10% NaBr solution (for Se). The mixture was cooled, centrifuged, and treated with further 10% LaCl3 solution, the supernatant solution was discarded and the ppt. was dissolved in 5 M HCl and diluted to volume Hydride-generation AAS or AFS was used to determine As or Se; the AFS detection limit was 25 or 10 ng g-1, respectively.
Coal Fluorescence Spectrophotometry Interferences

"Flow Injection Systems For Sample Introduction In Mass Spectrometry"
Anal. Chim. Acta 1988 Volume 214, Issue 1-2 Pages 385-390
John S. Canham and Gilbert E. Pacey

Abstract: The applications were studied of flow injection systems either for direct introduction of an analyte into the MS instrument or to convert the analyte to a suitable form for detection. Diagrams of the systems used are presented. A ploy(methyl methacrylate) membrane separator was used with the quadrupole MS flow injection system and a PTFE membrane separator with the single-focusing magnetic-sector MS flow injection system. The selectivity and sensitivity of MS increased the applications of flow injection analysis. The determination of As and CHCl3 are studied as examples.
Mass spectrometry Gas diffusion Kinetic Teflon membrane

"Tandem Online Continuous Separation And Determination Of Arsenic By Inductively Coupled Plasma Atomic Emission Spectrometry"
Anal. Chim. Acta 1990 Volume 234, Issue 1 Pages 133-139
A. Men&eacute;ndez Garc&iacute;a, E. S&aacute;nchez Ur&iacute;a and A. Sanz-Medel

Abstract: The principle of tandem on-line continuous separation techniques as an alternative means of introducing samples into plasmas was applied to the development of a sensitive, selective and convenient method for the determination of arsenic by inductively coupled plasma atomic emission spectrometry (ICP-AES). Arsenic is continuously extracted as AsI3 into xylene from the sample dissolved in 0.1 M potassium iodide solution in 7.2 M hydrochloric acid. The xylene phase (containing the analyte) is continuously mixed on-line with NaBH4 in dimethylformamide and acetic acid solutions. Arsine is thus continuously generated directly from the organic phase and is separated in a gas-liquid separation device which prevents most of the xylene phase vapor from reaching the ICP. The system was optimized for the continuous extraction of AsI3, the direct generation of arsine from xylene and the final ICP determination of arsenic. Finally, the tandem on-line continuous separation ICP detection system was applied to the determination of arsenic in real samples (white metal, cast iron, cupro-nickel and orchard leaves standard materials). Very good agreement between the experimental results and the certified values was obtained.
Spectrophotometry

"Multivariate Correction Of Chemical Interferences In Hydride-generation Atomic Absorption Spectrometry"
Anal. Chim. Acta 1992 Volume 268, Issue 1 Pages 115-122
G&uuml;nter Henrion*, Ren&eacute; Henrion, Ralph Hebisch and Birgit Boeden

Abstract: A mixture of simultaneously occurring elements, as exemplified by Se, Sb and As, was used to investigate chemical interferences. Measurements in batch mode were made with an AAS 30 spectrometer (Jenoptik, Jena), equipped with a hydride-generation system and an electrically heated quartz tube atomizer. Continuous-flow measurements were made on a Perkin-Elmer model 300 instrument with a quartz tube atomizer. Aqueous NaBH4 stabilized with 1% of NaOH was used as reductant, and the HCl was cleaned by sub-boiling distillation. To establish the effect of chemical interference, a training data set was established according to a factorial design for 64 synthetic samples. It was found that the system is dominated by Se - As interference. Multicomponent calibration by any accepted method of multivariate regression can effectively correct the systematic errors of measurement. As goodness of prediction is stable over time, the factorial design, once established, can be applied in routine analyzes. Generalization to more complex systems should be straightforward.
Spectrophotometry Interferences Multivariate calibration Factorial design

"Determination Of Arsenic And Selenium In Environmental Samples By Flow Injection Hydride-generation Atomic Absorption Spectrometry"
Anal. Chim. Acta 1992 Volume 270, Issue 1 Pages 231-238
Chris C. Y. Chan* and Ram S. Sadana

Abstract: Environmental samples such as soil, vegetation, water, sediments and industrial wastes were digested (except for water) by heating at 200°C with HNO3 - H2SO4 - HClO4 (6:3:1). The cooled digest or water was treated with concentrated HCl to reduce Se6+ to Se4+; for As analysis the solution was treated with 10% KI - 1% ascorbic acid (10:1) to reduce As5+ to As3+. The analytes were converted to the hydrides with 1% NaBH4 in an automated hydride-generation system. A stream of Ar (3 mL min-1) carried the evolved hydride via a gas - liquid separator and an impinger to a heated quartz tube atomizer for analysis by AAS. The effects of the experimental variables are discussed. Interference by Cu and Ni on the determination of Se was masked with 1,10-phenanthroline. The detection limits for both As and Se were 0.3 ng mL-1. The coefficient of variation was 2.6% for As in a sediment (n = 10) and 2% in water (n = 5); similar precision was obtained for Se. The results for the standard reference materials agreed closely with their certified values. Flow injection analysis is applied to sample introduction in conjunction with automated hydride generation and AAS for the determination of As and Se in environmental samples such as soil, vegetation, waters, sediments, and industrial wastes. A large sample loop was used to provide high sensitivities with an absorbance of 0.4 for 10 ng mL-1 for both As and Se. The samples, except waters, are digested with a mixture of nitric, sulfuric, and perchloric acids. Se6+ in the digested solutions is pre-reduced to Se4+ by exothermic reaction in 6-8 M HCl solution, and As5+ to As3+ by reacting with KI. The analyte is then converted to hydride by NaBH4 in an automated hydride generation system. The evolved hydride is carried through to a heated quartz tube by a stream of argon, and the atomic absorption of the analyte is measured. 1,10-Phenanthroline is used as masking agent to control interferences from Cu and Ni on Se. The detection limits for both As and Se are 0.3 ng mL-1, equivalent to 75 ng g-1 in solid sample. Precision is 2.6% RSD Results for standard reference materials agree closely with the certified values.
Environmental Environmental Environmental Vegetable Waste Spectrophotometry Reference material Interferences Volatile generation Volatile generation

"Different Sample Introduction Systems For The Simultaneous Determination Of Arsenic, Antimony And Selenium By Microwave-induced Plasma Atomic Emission Spectrometry"
Anal. Chim. Acta 1993 Volume 271, Issue 1 Pages 171-181
E. Bulska and P. Tsch&ouml;pel*, J. A. C. Broekaert, G. T&ouml;lg

Abstract: The determination of hydride-forming elements using different sample introduction procedure into microwave-induced plasmas (MIPs) has been studied. For the determination of As, Sb and Se analyte introduction was accomplished with a pneumatic concentric glass nebulizer,a graphite furnace, or with thydride generation followed by cold-trapping or hot-trapping in a graphite furnace. The detection limits obtained with different types of low power MIPs (toroidal, 1 or 3 filament MIPs) operated in a TM010 cavity according to Beenakker also were investigated. The construction of the flow system used for pre-concentration and the effects of reagent concentration, gas flow rates as with MIP-atomic emission spectrometry (AES) were investigated. The trapping of the hydrides followed by their vaporization showed substantial advantages over the other introduction systems investigated, especially with respect to power of detection. Further, mutual interferences being a big problem in atomic absorption spectrometry are widely absent in MIP-AES. Under compromise operating conditions the detection limits for As, Sb and Se are 0.4; 0.35; 0.25 ng mL-1 respectively, while the sample volume can be varied from 0.05 mL up to several milliliters.
Spectrophotometry Simultaneous analysis Volatile generation Volatile generation

"Simultaneous Determination Of Arsenic, Antimony And Selenium By Gas-phase Diode-array Molecular Absorption Spectrometry, After Preconcentration In A Cryogenic Trap"
Anal. Chim. Acta 1995 Volume 300, Issue 1-3 Pages 321-327
Susana Cabredo Pinillos, Jes&uacute;s Sanz Asensio* and Javier Galb&aacute;n Bernal

Abstract: Solutions of 4% NaBH4 (4 ml/min) and analyte mixture in 0.5 M HCl (35 ml/min) were passed through a mixer and to a system of two gas-liquid separators where the N2 carrier gas (20 ml/min) transferred the gaseous products to a water trap immersed in a bath of ice and salt (-10°C). The hydrides were retained in a glass U-tube in liquid N2. After trapping, the tube was removed from the cryogenic bath for > 5 min then heated for 1 min at 80°C. The hydrides were transported to a continuous-flow cell and placed in a diode-array spectrophotometer for measurement of the transient signals over the 190-250 nm range. Linear response ranges above 50 µg/l for As(III), 30 µg/l for Sb(III) and 200 µg/l for Se(IV) were obtained with detection limits of 22, 15 and 65 µg/l, respectively. Multiwavelength linear regression equations were used for the simultaneous determination of the three elements in synthetic samples and to study the effects of possible interfering species. The results were similar to those obtained by other hydride generation techniques.
Spectrophotometry Gas phase detection Interferences Preconcentration Cold trap

"Arsenic Speciation In Serum Of Uraemic Patients Based On Liquid Chromatography With Hydride Generation Atomic Absorption Spectrometry And Online UV Photo-oxidation Digestion"
Anal. Chim. Acta 1996 Volume 319, Issue 1-2 Pages 177-185
X. Zhang*, R. Cornelis, J. De Kimpe and L. Mees

Abstract: An on-line method was developed for the speciation of arsenic species in human serum, including monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB) and arsenocholine (AsC). The method is based on cation-exchange liquid chromatography (LC) separation, UV-photo-oxidation for sample digestion and continuous hydride generation (HG) atomic absorption spectrometry (AAS) for the measurement of arsenic in the LC eluent. By developing the technique of argon segmented flow in the post-column eluent, an substantial improvement in Chromatographic resolution for the separation of these four arsenic species was obtained. The LC separation, photo-oxidation, hydride generation and AAS measurement could be completed on-line within 10 min. The detection limits were 1.0, 1.3, 1.5 and 1.4 µg/l of arsenic for MMA, DMA, AsB and AsC, in serum respectively. The concentration of the 4 species was determined in serum samples of patients with chronic renal insufficiency. Only AsB and DMA were significantly detected by the present method. The main part of arsenic in human serum is AsB. No MMA, AsC and inorganic arsenic were detected in these 6 samples.
Serum Human HPLC Spectrophotometry Online digestion UV reactor Speciation Photochemistry

"Cysteine Enhancement Of The Cryogenic Trap Hydride AAS Determination Of Dissolved Arsenic Species"
Anal. Chim. Acta 1996 Volume 333, Issue 1-2 Pages 89-96
A. G. Howard*, and C. Salou

Abstract: Pre-derivatization of arsenic species with L-cysteine prior to their determination by a modified cryogenic trap hydride AAS procedure leads to more uniform sensitivities to arsenite, arsenate, methylarsonate and dimethylarsinate and improved resistance to interferences from metal ions. This pre-treatment can be carried out at room temperature, or more rapidly by microwave heating. The conditions required for the reduction of the resulting arsenic-cysteine complexes differ from those required for the generation of hydrides from the parent compounds. In particular, lower levels of acid are required, resulting in a reduction in the acid-derived blank contributions to the inorganic arsenic response. The pre-treatment procedure has been found to improve the performance of the hydride trap procedure when measurements are made in the presence of metals such as iron(II), nickel(II), cobalt(II), manganese(II) and copper(II) which interfere in the conventional cryogenic trap HG-AAS speciation procedures. The detection limits (3s) of the four species were in the range 30-99 pg with relative standard deviations of 3.1-7.9%, giving with 1 mL samples, detection limits of ca 50 ng L-1.
Spectrophotometry Optimization

"Arsenic Speciation In Biological Samples By Online High Performance Liquid Chromatography-microwave Digestion-hydride Generation-atomic Absorption Spectrometry"
Anal. Chim. Acta 1996 Volume 334, Issue 3 Pages 261-270
Kathryn J. Lamble and Steve J. Hill*

Abstract: A system capable of the separation of arsenic species by on-line high performance liquid chromatography prior to their online decomposition by microwave digestion, pre-reduction with L-cysteine and analysis by hydride generation-atomic absorption spectrometry has been developed. This approach enables the full speciation of arsenobetaine, monomethylarsonic acid, dimethylarsinic acid and total inorganic arsenic (arsenite + arsenate) in biological samples. Simple modification of the system allows for the determination of the total arsenic content of the sample. In addition quantification of the total reducible arsenic species (arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid) can be achieved by on-line prereduction-hydride generation-atomic absorption spectrometry. Procedures were validated by analysis of the certified reference materials NRCC DORM-1 and TORT-1 and gave results in good agreement with the certified values.
Biological Spectrophotometry Microwave Online digestion Speciation

"Determination Of Arsenic By Hydride-generation Gas Diffusion Flow Injection Analysis With Electrochemical Detection"
Anal. Chim. Acta 1996 Volume 334, Issue 1-2 Pages 193-197
J. R. Farrell, P. J. Iles,* and Y. J. Yuan

Abstract: A 300 µL sample of As2O3 in 8% (v/v) HCl was injected into 8% (v/v) HCl that had been premixed with 0.2% (w/v) NaBH4 solution in 0.01 M NaOH. AsH3 generated in the donor stream (1 ml/min) diffused through the PTFE membrane of a gas diffusion cell (described) into 0.5 mM Br2 pumped (1 ml/min) through the upper chamber that was fitted with a flow-through conductometric detector. Calibration graphs were linear for 2.5-50 mg/l of As, with detection limits of 2 and 0.2 mg/l for flow rates of 1 and 0.3 ml/min, respectively. The RSD (n = 6) was 4.6% at 10 ml/min. Alternatively, AsH3 generated with 0.5% (w/v) NaBH4 solution in 0.01 M NaOH (1 ml/min) was trapped in 0.01 M H2SO4 (1 ml/min) and determined in a thin-layer flow-through amperometric cell with a dual Au working electrode and an Ag/AgCl reference electrode. Calibration graphs for 0.01-1 mg/l of As and 0.5-40 mg/l As were non-linear. The detection limit was 0.01 mg/l and the RSD (n = 6) were 3.4 and 4% for 1 and 0.1 mg/l of As, respectively.
Amperometry Conductometry Gas phase detection Gas diffusion Teflon membrane Volatile generation

"Fast Automated Determination Of Toxicologically Relevant Arsenic In Urine By Flow Injection Hydride Generation Atomic Absorption Spectrometry"
Anal. Chim. Acta 1997 Volume 349, Issue 1-3 Pages 313-318
T. Guo*, J. Baasner and D. L. Tsalev

Abstract: Lower results for arsenic in urine are encountered when potassium iodide-ascorbic acid is used as a pre-reductant in flow injection-hydride generation atomic absorption spectrometry (FI-HGAAS). For the determination of toxicologically relevant arsenic in urine, i.e. the sum of inorganic As(III) and As(V) and its organic metabolites (monomethylarsonate and dimethylarsinate) has been elaborated a simple analytical procedure: ten-fold diluted urine is treated with L-cysteine (1%, m/v) in 0.03 mol 1-1 hydrochloric acid medium for 1 h, and then a 500 µL aliquot is directly injected into an automated, commercially available FI-HGAAS system. The effects of most critical instrumental and chemical parameters have been studied and optimum conditions are recommended, comprising of relatively low sample and carrier acidities, 0.03 and 0.01 mol L-1 HCl, respectively, higher sodium tetrahydroborate levels (0.5%, m/v), lower flow rates of reagents than that typically recommended for this system to ensure longer reduction and residence times in the gas-liquid separator, and integrated absorbance measurements for eliminating the residual kinetic effects in hydride generation and transport of individual arsenic species. The recoveries of spiked As(III), As(V), MMA and DMA in urine are 100%, 100%, 96% and 95%, respectively. This procedure has been validated by analysis of several certified reference materials and collaborative study samples, the results being in good agreement with the certified values. The limit of detection (3s) is 0.1 µg L-1 in 1:10 diluted urine, corresponding to 1 µg L-1 of As in undiluted urine. The relative standard deviation is 2% and 7% (within-run and between-run in three successive days, respectively) at 3 µg L-1 (1.5 ng) As level. The sampling frequency is up to 50-55 measurements per hour.
Urine Spectrophotometry Speciation

"Solvent Extraction Of Arsenic From Acid Medium Using Zinc Hexamethylenedithiocarbamate As An Extractant"
Anal. Chim. Acta 1998 Volume 360, Issue 1-3 Pages 43-52
Anthony R. K. Dapaah and Akimi Ayame*

Abstract: Using zinc hexamethylenedithiocarbamate (Zn(HMDC)2) and flame atomic absorption spectrometry (FAAS) and/or flow injection hydride generation atomic absorption spectrometry (FI-HGAAS), solvent extraction of As(III) from HCl and H2SO4 media into 2,6-dimethyl-4-heptanone (diisobutyl ketone, DIBK) was examined. Arsenic(III) was quantitatively extracted with 2.41 X 10^-3 mol L-1 Zn(HMDC)2 from about 0.004 (pH 2.4) to 4 mol L-1 HCl and H2SO4 aqueous solutions. The logarithmic conditional extraction constant of As(HMDC)3 in the HCl-DIBK system was determined to be 8.3 +- 0.7, by the measurement of the distribution ratios of Zn(II) and As(III). The effectiveness of the proposed extraction method was ascertained in the determination of As in geochemical standard reference materials supplied by the Geological Survey of Japan. Furthermore, the analysis of arsenic in procedural blanks was 0.083+-0.003 µg l-1.
Geological Spectrophotometry Spectrophotometry Reference material

"Comparison Of Inorganic Films And Poly(4-vinylpyridine) Coatings As Electrode Modifiers For Flow Injection Systems"
Talanta 1986 Volume 33, Issue 11 Pages 911-913
James A. Cox and Krishnaji R. Kulkarni

Abstract: The flow injection determination of As(III) was carried out with amperometric detection by using a vitreous-carbon electrode modified with hexacyanoruthenate(II) by electrochemical deposition from a solution of RuCl3 and K4Ru(CN)6. Calibration graphs were rectilinear from 5 to 100 µM, with a detection limit of 300 pg; the response was reproducible for several days. A vitreous-carbon electrode was coated with quaternized poly-(4-vinylpyridine), then modified with IrCl64- and IrCl63- from a solution of K4IrCl6 and used for the oxidative determination of NO2-. Calibration graphs were non-rectilinear and irreproducible, and peaks were broad. An iodine-modified platinum electrode gave results for NO2- analogues to those obtained for As(III), but a coating of quaternized poly-(4-vinylpyridine) adversely affected the sensitivity.
Amperometry Electrode Electrode Electrode

"Online Photo-oxidation For The Determination Of Organo-arsenic Compounds By Atomic Absorption Spectrometry With Continuous Arsine Generation"
Talanta 1991 Volume 38, Issue 2 Pages 167-173
Raja H. Atallah and David A. Kalman*

Abstract: A flow injection system is described in which organo-arsenic compounds are oxidized to AsO3-, reduced to AsH3- then further reduced to AsH3 for AAS detection. Sample solution was injected into a stream (2 mL min-1) of water, which was mixed with 2% K2S2O8 in 1% NaOH (0.6 mL min-1) and passed through a PTFE reaction coil (5 m x 0.5 mm) wrapped around a Hg lamp. The eluate was mixed sequentially with 8 M HCl and 3% NaBH4 in 0.5% NaOH (both at 0.8 mL min-1), passed through a reaction coil (4 m x 1.5 mm) and merged with He (350 mL min-1) before being passed into a phase separator. Arsine in the gas was determined by AAS at 193.7 nm. Calibration graphs were rectilinear for 3 ppm of As. Recoveries were >95% for biological and environmental samples, including dimethylarsinic- and phenylarsonic-acids and arsenobetaine.
Spectrophotometry Phase separator

"Estimation Of The Method Evaluation Function For The Determination Of Hydride-generating Arsenic Compounds In Urine By Flow Injection Atomic Absorption Spectrometry"
Talanta 1992 Volume 39, Issue 5 Pages 469-474
Ann J. L. M&uuml;rer*, Anne Abildtrup, Otto M. Poulsen and Jytte Molin Christensen,

Abstract: The method described by Hansen et al. (Ann. Occup. Hyg., 1991, 35, 603) was used to validate the analysis in which the samples were injected into a carrier stream and mixed with 0.5% NaBH4 solution in 0.04% NaOH. The generated arsines were carried from a gas - liquid separator by Ar to a quartz cell at 900°C and were determined at 197.3 nm. The evaluation procedure demonstrated that standard-additions calibration was necessary for acceptable performance at low concentration. (i.e., after a low-dose exposure). By this means a limit of detection of 2.9 µg L-1 was achieved. A direct flow injection atomic-absorption spectrometric (FIA-AAS) method for the assessment of inorganic As compounds and their metabolites was developed and statistically evaluated by the estimation of the method evaluation function (MEF), which provides detailed information on the analysis performance of the method. i.e., the average combined uncertainty and the magnitude of potential systematic errors. The method evaluation study demonstrated that the use of standard addition was a necessity to obtain an acceptable method performance at low concentrations. typical for low dose exposure. In contrast, the use of calibration curves resulted in a method with reduced sensitivity and high systematic error. The developed method, using standard addition, had a limit of detection (2.9 µg/mL) sufficiently low for the determination of hydride-generating As species in urine from non-exposed and low exposed persons. Organoarsenicals such as arsenobetaine and arsenocholine are not detected by this method. Hence, the contribution of these compounds derived from a diet containing seafood does not affect the monitoring of inorganic As compounds after occupational or environmental exposure. The high capacity of the FIA-AAS system (31-min per sample measured by standard addition) together with the low limit of detection makes this method suitable for biological monitoring of inorganic As exposure even though standard addition is required.
Urine Spectrophotometry Volatile generation Phase separator Standard additions calibration Volatile generation

"Determination Of Arsenic By Inductively Coupled Plasma Atomic-emission Spectrometry Enhanced By Hydride Generation From Organized Media"
Talanta 1992 Volume 39, Issue 11 Pages 1517-1523
B. Aizpun Fernandez, C. Valdes-Hevia y Temprano, M. R. Fernandez de la Campa and A. Sanz-Medel*P. Neil,

Abstract: The cited method is based on continuous-flow generation of arsine with NaBH4 from a didodecyldimethylammonium bromide (I) vesicular medium. The analytical performance of this technique was superior to the generation of the hydride from aqueous media. Optimization of experimental parameters is described. The detection limit (0.6 ppb) was improved by a factor of 2 and there was a greater tolerance to interferences for arsine generated from I vesicles; precision of the As determination was also improved. The method was validated for low As level determinations in two Certified Reference Materials (sediments). The potential of organized media to improve hydride generation is also discussed.
Environmental Mass spectrometry Optimization Preconcentration Volatile generation Interferences Reference material Volatile generation

"Determination Of Urinary Arsenic And Impact Of Dietary Arsenic Intake"
Talanta 1993 Volume 40, Issue 2 Pages 185-193
Xiao-Chun Le, William R. Cullen* and Kenneth J. Reimer,

Abstract: Urine samples (10 ml) were treated with 0.1 g of L-cysteine to obtain the same sensitivity from As(III), As(V), monomethylarsonic acid and dimethylarsinic acid. Portions (0.1 ml) were injected into the carrier stream and mixed with 0.7 M HCl and 0.65 M NaBH4 in 0.1 M NaOH. The AsH3 generated from these four species were passed through a gas-liquid separator and thence to the air - acetylene flame for AAS. A second sample (40 ml) without the cysteine addition was heated in a microwave oven in the presence of 4.5 g of K2S2O8 and 2.7 g of NaOH for five 3 min periods. This converted all arsenic species to As(V) (including arsenobetaine, which was not reduced to AsH3 by NaBH4). The solution was diluted to 50 mL and the total As(V) was determined as before but with 3 M HCl. This method is capable of differentiating between different sources of urinary intake, e.g., occupational exposure and dietary intake.
Urine

"Determination Of Arsenic And Selenium In Spinach And Tomato Leaves Reference Materials Using Flow Injection And Atomic Absorption Spectrometry"
Talanta 1994 Volume 41, Issue 10 Pages 1785-1790
Rajananda Saraswati and Robert L. Watters, Jr.*

Abstract: Dried tomato or spinach leaves were refluxed for 4 h with HNO3 and H2SO4, the solutions were cooled, HClO4 was added and the solution heated for 5 h until dense fumes appeared. After cooling, HCl was added, the solutions were heated for 15 min at near boiling and allowed to cool. The digests were diluted with water and a portion was mixed with a reducing agent comprising 10% KI and 5% ascorbic acid for 1 h to reduce As(V) to As(III). A second portion of diluted digest was heated with 1:1 HCl in a water bath at 90°C for 25 min to reduce Se(VI) to Se(IV). Using 5% HCl as a carrier stream (10 ml/min) in the FIA system the sample was swept from the injection loop (200 µL) to a mixing coil (11 cm) where it reacted with a reductant solution of 2.5 g/l of NaBH4 in 0.05% NaOH (6 ml/min). The gaseous hydrides of arsenic and selenium are separated from the solution and swept by Ar gas to a quartz absorption cell heated at 900°C in the light path of an electrodeless discharge lamp in an AAS for determination at 193.7 and 196 nm for As and Se, respectively. Calibration graphs were linear for 0-5 ng/ml of As or Se with detection limits of 0.15 and 0.17 ng/ml, respectively.
Plant Spectrophotometry

"Determination Of Ultratrace Amounts Of Arsenic(III) By Flow Injection Hydride Generation Atomic Absorption Spectrometry With Online Preconcentration By Coprecipitation With Lanthanum Hydroxide Or Hafnium Hydroxide"
Talanta 1996 Volume 43, Issue 6 Pages 867-880
Steffen Nielsena, Jens J. Slotha and Elo H. Hansen

Abstract: Sample stream (4 ml/min) was merged with a stream of coprecipitation agent (0.6 ml/min) of La(III) or Hf(IV) for 100 s and passed through a 6 cm mixing coil. The resulting stream merged with a buffer stream (0.6 ml/min) of 0.3 M ammonium chloride and through a knotted reactor (200 cm). The precipitate was collected on the walls of the reactor and the effluent was discarded. After precipitation, the coprecipitation and buffer stream flows were stopped and a stream of HCl (8.7 ml/min) was passed through the reactor to dissolve the precipitate. The analyte plug passed to a hydride generating system where it merged with a stream of sodium tetrahydroborate (1.5 ml/min), through a reaction coil (60 cm) to a gas-liquid separator. The arsine and evolved H2 were swept to the atomizer cell by Ar carrier gas and the absorption was measured by AAS. La(III) was more effective for collecting As(III) than Hf(IV). The detection limit was 0.003 µg/l of As(III) with a RSD (n = 11) of 1% at 0.1 µg/l.
Spectrophotometry Preconcentration Coprecipitation Knotted reactor Ultratrace

"Analytical Methodology For Speciation Of Arsenic In Environmental And Biological Samples"
Talanta 1997 Volume 44, Issue 9 Pages 1581-1604
Marcela Burguera and Jos&eacute;Luis 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.
Environmental Biological Sample preparation Spectrophotometry Spectrophotometry HPLC Review Speciation

"Flow Injection Hydride Generation System For The Determination Of Arsenic By Molecular Emission Cavity Analysis"
Analyst 1986 Volume 111, Issue 2 Pages 171-174
M. Burguera and J. L. Burguera

Abstract: Nanogram amounts of As have been determined in µL samples of solution by flow injection hydride generation with NaBH4 solution, followed by separation of AsH3 from the liquid phase and transport with Ar to the molecular-emission cavity, where the AsO emission intensity is measured at 400 nm. The effects of interfering ions, including those of Ni, Ag, Zn, Cu, Te and Se, are eliminated by using a 0.01 M EDTA - 0.2 M NaI - 1.5 M HCl sample carier solution The calibration graph is rectilinear for 0.1 to 10 µg mL-1 of As, and the detection limit is 0.08 µg mL-1. The method allows a sampling rate of ~100 measurements h-1. The technique is illutrated by the determination of As in NBS orchard leaves.
Spectrophotometry Interferences Reference material

"L-Cysteine As A Reducing And Releasing Agent For The Determination Of Antimony And Arsenic Using Flow Injection Hydride-generation Atomic Absorption Spectrometry. 2. Interference Studies And The Analysis Of Copper And Steel"
Analyst 1993 Volume 118, Issue 11 Pages 1425-1432
Bernhard Welz and Marcella Sucmanov&aacute;

Abstract: The method described in Part I (see abstract number 5D157) was used for the determination of Sb and As in Cu and steel. Cu was digested by cautious treatment with 7 and 14 M HNO3 and the digest was diluted with water and mixed with 10% L-cysteine solution Steel was heated with 10 M HCl followed by sequential treatment with 14 and 7 M HNO3, H2O2 and 7 and 14 M HNO3. The digest was evaporated to near-dryness and the peroxide-acid sequence was repeated 4 times at 135°C. The final residue was dissolved in 7 M HNO3 before the addition of 5% L-cysteine solution The resulting sample solution were diluted with water before analysis. Tolerance limits for Ni(II) and Cu(II) were 250 and 500 mg/l, respectively, in the determination of Sb. The corresponding limits in the determination of As were 200 mg/l and >1000 mg/l. However, if KI was used as reductant instead of L-cysteine, only 100 mg/l could be tolerated. In the analysis of standard reference materials, results agreed with certified values.
Metal Alloy Sample preparation Spectrophotometry Interferences Reference material

"L-Cysteine As A Reducing And Releasing Agent For The Determination Of Antimony And Arsenic Using Flow Injection Hydride-generation Atomic Absorption Spectrometry. 1. Optimization Of The Analytical Parameters"
Analyst 1993 Volume 118, Issue 11 Pages 1417-1423
Bernhard Welz and Marcella Sucmanov&aacute;

Abstract: The use of L-cysteine instead of KI as a pre-reductant for Sb(V) and As(V) in flow injection AAS was studied. Reduction to Sb(III) and As(III) was achieved at room temperature within 5 and 30 min, respectively, which was similar to the performance of KI. However, much lower acid and reagent concentrations were required with L-cysteine than with KI. Also, analyte solution containing L-cysteine were stable for at least a week, whereas those containing KI had to be prepared daily. The optimum carrier and sample medium for the determination of Sb and As by this technique were 1 and 0.1 M HCl, respectively, in the presence of 1% L-cysteine. A solution of 0.05% sodium tetrahydroborate and 0.5% NaOH was used for hydride generation. The detection limits were 0.05 µg/l for Sb and 0.01 µg/l for As. The calibration graphs were linear up to 10 µg/l of Sb and 5 µg/l of As, using integrated absorbance for evaluation. The RSD (n = 10) was 2% for 5 µg/l of both elements. For Part II see abstract number 5E18.
Spectrophotometry Redox Optimization Volatile generation Volatile generation

"Comparison Of Reflux And Microwave Oven Digestion For The Determination Of Arsenic And Selenium In Sludge Reference Material Using Flow Injection Hydride-generation And Atomic Absorption Spectrometry"
Analyst 1995 Volume 120, Issue 1 Pages 95-99
Rajananda Saraswati, Thomas W. Vetter and Robert L. Watters Jr.

Abstract: Sludge (0.25 g) was mixed with 5 mL concentrated HNO3 and 5 mL concentrated H2SO4, and a five-stage microwave oven digestion procedure (details tabulated) was used to digest the sample. The maximum temperature and pressure reached during the digestion were 175°C and 190 psi, respectively. The resulting solution was heated on a hot-plate until all the HNO3 was removed, and then diluted to 100 mL with 2% HCl. For As determination, 10 mL of the solution were treated with 5 mL of a solution of 10% KI and 5% ascorbic acid for 1 h before analysis. For Se determination, 10 mL of the solution was diluted to 100 mL with HCl (1:1), followed by heating at 90°C for 25 min before analysis. Analyses were performed by injecting the sample solution (40 µL) into a carrier stream of 10% HCl for subsequent reaction with a solution of 0.25% NaBH4 in 0.05% NaOH. The gaseous hydrides of As or Se produced were analyzed by AAS at 193.7 or 196 nm, respectively. Calibration graphs were linear from 5-20 and from 2-10 ng/ml of As and Se, respectively. The corresponding detection limits were 0.15 and 0.17 ng/ml. Microwave oven digestion with HNO3/H2SO4 provided results comparable to those obtained by reflux column digestion using HNO3/H2SO4/HClO4 and afforded shorter sample preparation times.
Sludge Sample preparation Spectrophotometry Reference material Method comparison

"Effect Of High Salt Concentrations On The Determination Of Arsenic And Selenium By Flow Injection Hydride Generation Electrothermal Atomic Absorption Spectrometry"
Analyst 1998 Volume 123, Issue 8 Pages 1697-1701
Robert I. Ellis, Nils G. Sundin, Julian F. Tyson, Susan A. McIntosh, Christopher P. Hanna and Glen Carnrick

Abstract: In the determination of As and Se by flow injection hydride generation ETAAS, the presence of up to 20% NaCl enhanced the signals for 20 µg L-1 As and Se by up to 28%. The enhancement was obtained with a variety of gas-liq. separators. A systematic study of the possible causes of the signal enhancement in the determination of Se was undertaken, from which the effect originated in the processes responsible for the distribution of the H selenide between the solution and gas phases. Processes related to the transport of the analyte from the gas-liq. separator and the trapping of the analyte on the interior of the atomizer were not affected by the presence of dissolved salts. As Na is transported to the atomizer, aqueous aerosol was deposited in the atomizer, although the quantities were irreproducible. The enhancement could be eliminated by increasing the borohydride concentration. However, with the small volume gas-liq. separator, this latter approach was limited because of carry-over of liquid to the atomizer. The effect could be compensated for by adding up to 40% (m/v) of salt to the borohydride reagent.
Spectrophotometry Ionic strength Dissolved solids Phase separator Signal enhancement

"Microporous Polytetrafluoroethylene Membrane Gas-liquid Separator For Flow Injection Hydride Generation And Inductively Coupled Plasma Atomic Emission Spectrometry"
J. Anal. At. Spectrom. 1988 Volume 3, Issue 8 Pages 1091-1095
Xiaoru Wang and Ramon M. Barnes

Abstract: A gas - liquid phase separator is described that contains a micro-porous PTFE membrane clamped between grooved aluminum plates and is equipped with two inlet and two outlet ports. With flow injection controlled AsH3 generation, flow rates of 0.3 l min-1 for Ar carrier gas and 0.8 mL min-1 for sample were chosen. With use of a pore size of 1 µm and a PTFE membrane supported on non-woven polyester, rectilinear calibration graphs for both peak height and area were obtained in the range 25 to 200 ng mL-1 of As. With 40 µL sample injections, a steady response signal was attained in ~3 s and the absolute detection limit (peak area) was ~1 pg of As. At 100 ng mL-1 of As the precision was 6%.
Spectrophotometry Phase separator Teflon membrane

"Micro-porous Polytetrafluoroethylene-tubing Gas - Liquid Separator For Hydride Generation And Inductively Coupled Plasma Atomic-emission Spectrometry"
J. Anal. At. Spectrom. 1988 Volume 3, Issue 8 Pages 1083-1089
Ramon M. Barnes and Xiaoru Wang

Abstract: For the determination of As by AsH3 generation - ICP-AES, a concentric gas - liquid phase separator based on micro-porous PTFE tubing was tested under both continuous and flow injection generation conditions. Various physical operating parameters, e.g., tubing diameter and porosity and carrier gas flow rate, were optimized, and performance matched that of conventional, dual-phase and packed-bead separators for both continuous and flow injection generation. With continuous generation a rectilinear calibration graph was obtained for the range 15 to 100 ng mL-1 of As. For a reference material certified at 76 ± 7 ng mL-1 of As, the determined content was 79.6 ± 4.2 ng mL-1.
Spectrophotometry Optimization Phase separator Reference material Teflon membrane

"Determination Of Arsenic In A Nickel-based Alloy Using A Microwave Digestion Procedure And A Continuous-flow Hydride-generation Atomic Absorption System Incorporating Online Matrix Removal"
J. Anal. At. Spectrom. 1989 Volume 4, Issue 2 Pages 181-184
Philip G. Riby, Stephen J. Haswell and Roman Grzeskowiak

Abstract: Sample (1 g) was dissolved in HNO3 - HF in a microwave digestion unit over 1 h, and the resulting solution was passed through a Bond Elut strong cation-exchange column to remove Ni. The resulting solution was then mixed in a flow injection system with 1% NaBH4 solution in aqueous 1% NaOH followed by 4 M HCl, and the generated AsH3 was stripped by Ar in a gas - liquid separator and determined at 193.7 nm. The cation-exchange resin could be regenerated by washing with 1 M HCl. Recovery of 25 ppm of As added to low-As Ni-based alloy was 98%. The limit of detection in the final solution was 1.3 ppb of As, the calibration graph was rectilinear up to 20 ppb, and the coefficient of variation (n = 10) for 10 ppb was 3%.
Alloy Ion exchange Sample preparation Spectrophotometry Column Matrix removal Detection limit Volatile generation PPB Volatile generation

"Determination Of Arsenic In An Organic Phase By Coupling Continuous-flow Extraction - Hydride Generation With Inductively Coupled Plasma Atomic-emission Spectrometry"
J. Anal. At. Spectrom. 1989 Volume 4, Issue 7 Pages 581-585
Alberto Men&eacute;ndez Garc&iacute;a, J. Enrique S&aacute;nchez Ur&iacute;a and Alfredo Sanz-Medel

Abstract: Arsenic is extracted (as AsI3) from sample solution into xylene in the presence of KI and HCl, and the extract is mixed with NaBH4 in DMF and acetic acid in a continuous-flow apparatus. The mixture is passed through a gas - liquid separator, and AsH3 is determined by ICP-AES at 228.81 nm. The calibration graph is rectilinear from 0.01 to 100 µg mL-1. The coefficient of variation is 2.0% at 0.1 µg mL-1 (n = 10). There is no interference by equal amounts of Pt, up to 17.5-fold amounts of Cu or up to 50-fold amounts of many metals, Se or Ge. The limit of detection is 0.7 ng mL-1. The method is applied to alloys and biological reference material.
Alloy Biological Spectrophotometry Sample preparation Extraction Phase separator Interferences Reference material

"Use Of Flow Injection For Inline Elimination Of Interferences In Hydride Generation Atomic Absorption Spectrometry"
J. Anal. At. Spectrom. 1990 Volume 5, Issue 8 Pages 681-686
Graham D. Marshall and Jacobus F. van Staden

Abstract: A modified version of the flow injection system described previously (Ibid., 1990, 5, 685) was used to remove interference from (i) As(V) or Sb(V) in the determination of As or Sb, respectively, by reduction of the sample with KI, (ii) noble metals in the determination of Se, As and Bi by masking with Te(IV) and (iii) base metals, e.g., Ni(II), in the determination of As and Se by ion-exchange chromatography on a Bio-Rad AG50W-X8 column. In the determination of 0.4 µg mL-1 of Se, e.g., interference from up to 0.1 mg mL-1 of Pb was eliminated by reacting the sample with a stream of 4.8 M HCl containing 0.2 mg L-1 of Te(IV) (2 mL min-1) before reduction with NaBH4.
Spectrophotometry Interferences

"Design And Optimization Of A Flow Injection Hydride Generator And Its Use For Automated Standard Additions"
J. Anal. At. Spectrom. 1990 Volume 5, Issue 8 Pages 675-679
raham D. Marshall and Jacobus F. van Staden

Abstract: The flow injection hydride generator is described and depicted schematically. The sample is injected into an acidic carrier stream which is subsequently merged with the reductant. The apparatus allows rapid analysis, ease of automation and simple inline handling of interferences. To determine, e.g., As, the sample was injected into a stream of 4.8 M HCl (1.8 mL min-1) and mixed with a stream of aqueous NaOH (10 g l-1) containing 1.0% of NaBH4 in a reaction tube (50 cm x 1.5 mm). An Ar stream (35 mL min-1) was used to strip the AsH3 from the solution in a separator with a cotton gauze membrane and the As was determined by AAS at 193.7 nm. Calibration graphs were rectilinear for 40 ng to 0.5 µg mL-1 of As with coefficient of variation 2.9% (n = 10); the detection limit was 8 ng mL-1 of As. The detection limits of Bi, Sb, Se and Te were 2, 10, 6 and 3 ng mL-1, respectively, while those of Ge, Pb and Sn were similar to flame AAS values.
Spectrophotometry Automation Optimization Apparatus Interferences Membrane Detection limit Standard additions calibration

"Flow Injection - Electrochemical Hydride-generation Technique For Atomic Absorption Spectrometry"
J. Anal. At. Spectrom. 1992 Volume 7, Issue 2 Pages 287-292
Yuehe Lin, Xiaoru Wang, Dongxing Yuan, Pengyuan Yang, Benli Huang and Zhixia Zhuang

Abstract: A flow injection - electrothermal hydride generation technique for AAS has been developed in order to avoid the use of sodium tetrahydroborate, which is capable of introducing contamination. A specially designed thin-layer electrolytic flow cell (diagram given) for hydride generation was used in a normal flow injection system coupled to an electrically heated T-tube atomizer for atomic absorption measurements. The sample was injected into the electrolyte carrier stream flowing to the electrolytic cell, where hydride-forming elements were reduced to gaseous hydrides. The effects of factors such as the eletrode material, electrolyte, current density and carrier stream flow rate, on the rate of formation of the hydride and interferences were studied. The technique was used to determine of As in mangrove leaves, Se in traditional Chinese medicines and Sb in polyester film. The detection limits were 0.45, 0.62 and 0.92 ng mL-1 of As, Se and Sb, respectively.
Leaves Chinese Spectrophotometry Electrochemical product generation Volatile generation Interferences Volatile generation

"Determination Of Arsenic In A Nickel-based Alloy By Flow Injection Hydride-generation Atomic Absorption Spectrometry Incorporating Continuous-flow Matrix Isolation And Stopped-flow Pre-reduction Procedures"
J. Anal. At. Spectrom. 1992 Volume 7, Issue 2 Pages 315-322
Julian F. Tyson, Stephen G. Offley, Nichola J. Seare, Helen A. B. Kibble and Craig Fellow

Abstract: A sample (1 g) of Ni alloy was mixed with 4% HNO3 and 40% HF and subjected to microwave digestion before injection into a flow injection manifold. The manifold incorporated a column (5 cm x 3 mm) of Dowex 50W-X200 for removal of interference from Ni and a stopped-flow pre-reduction unit for conversion of As(V) to As(III) with 30% KI and 12 M HCl. The As(III) solution was injected into a stream of water and merged with streams of 3.6 M HCl and 1% NaBH4 solution for hydride-generation in an open-tubular reactor. Arsine separated in a glass U-tube gas - liquid separator was passed to a silica-tube atomizer for AAS. A limit of detection of 3.9 ng mL-1 of As was obtained. A flow system, incorporating a microcolumn of strongly acidic cation-exchange resin (Dowex 50W), to achieve continuous-flow matrix isolation, was used to eliminate nickel interference in the determination of arsenic in a nickel-based alloy by flow injection hydride generation atomic absorption spectrometry. A stopped-flow iodide preredn. procedure within the matrix isolation unit converted all arsenic present in the sample into As(III) prior to determination with a tube-in-flame atomizer. The flow injection valve interface between the matrix isolation and hydride generation manifolds allowed sep. optimization of each chemical After removal of the nickel, the sample stream, flowing at 2.2 mL min-1, was merged first with a stream of 12 mol L-1 hydrochloric acid flowing at 2.2 mL min-1 and then with a stream of potassium iodide solution (30% m/v) flowing at 1.4 mL min-1. For stop times between 5 and 30 s, an average recovery of 97% with respect to As was obtained. A 400 µL volume of solution was then injected into a water carrier stream (flowing at 11.0 mL min-1), merged with 3.6 mol L-1 hydrochloric acid flowing at 3.2 mL min-1 and a stream of 1.0% (m/v) sodium tetrahydroborate solution After passage through a 600 mm open-tubular reactor argon was merged at 400 L min-1 and the arsine separated in a glass U-tube separator. A 0.2 µm polytetrafluoroethylene membrane filter in the gas transfer line removed aerosol droplets with consequent improvement in the performance of the tube atomizer. The procedure was successfully applied to the determination of arsenic in a nickel-based alloy reference material (BCS-346) containing 50 µg g-1 of arsenic for which a sealed-vessel microwave digestion procedure, involving nitric and hydrofluoric acids, was found to produce arsenic in the +5 oxidation state. A characteristic concentration. of 2.0 ng mL-1 of arsenic and a limit of detection of 3.9 ng mL-1 of arsenic were obtained with the preredn. procedure (which diluted the samples by a factor of 2.7) for a set of operating parameters optimized with respect to interference tolerance and throughput in addition to sensitivity. Under these conditions a sample throughput of 54 h-1 was obtained.
Alloy BCS 346 Sample preparation Spectrophotometry Stopped-flow Dowex Optimization Interferences Reference material Matrix removal

"Use Of A Flow Injection Hydride-generation Technique In Non-dispersive Atomic-fluorescence Spectrometry"
J. Anal. At. Spectrom. 1992 Volume 7, Issue 4 Pages 667-674
Tiezheng Guo, Mingzhong Liu and Werner Schrader

Abstract: Parameters were established for the determination of As, Sb, Bi, Hg, Se and Te. The optimum NaBH4 concentration was 0.4% except for As (0.7%), with a flow rate of 400 to 500 mL min-1 of Ar and a furnace temperature of ~750°C. The calibration graphs were rectilinear within ranges up to 300 µg L-1, and the detection limits were between 0.02 and 0.2 µg L-1. The coefficient of variation ranged from 1 to 2%. The feasibility of using a flow injection (FI) hydride generation technique in conjunction with atomic fluorescence spectrometry (AFS) was investigated. Parameters were established for the determination of Sb, As, Bi, Hg, Se, and Te. Among the parameters that were found to have a more pronounced influence on performance were the concentration. of NaBH4, the carrier gas flow, the observation height, and the temperature of the atomizer cell. Compared with the manual sampling system (or batch system), the relative detection limits of the FI combination were better by factors of 2.5-10. By using FI, the sample volume was reduced to 500 µL, hence, the absolute detection limits were even better with improvements of between 10- and 50-fold depending on the element. The absolute detection limit for Se using the FI technique was 0.035 ng, while with the batch system it was 0.8 ng. Similarly, Hg detection limits with the FI technique and the batch system were found to be 0.015 and 0.4 ng, respectively. The best improvement in the abs. detection limits was found for Te, which with the FI technique was 0.02 ng while with the batch system it was 1.0 ng. The linear ranges were typically 2-3 orders of magnitude of analyte concentrations, which is much wider than that of atomic absorption spectrometry. Sampling frequency was typically 120 injections per h, and since a double-channel AFS instrument was used in this work, pairs of elements such as As, Sb and Bi, Hg were measured simultaneously, which equates to 240 measurements per h. The technique was applied to the determination of hydride forming elements in geological reference materials.
Geological Fluorescence Fluorescence Optimization Reference material Simultaneous analysis Linear dynamic range

"Optimization And Use Of Flow Injection Vapor-generation Inductively Coupled Plasma Mass Spectrometry For The Determination Of Arsenic, Antimony And Mercury In Water And Seawater At Ultra-trace Levels"
J. Anal. At. Spectrom. 1993 Volume 8, Issue 1 Pages 35-40
Andreas Stroh and Uwe V&ouml;llkopf

Abstract: An Elan 5000 ICP mass spectrometer and a FIAS-200 equipped with an AS-90 autosampler for online flow injection vapor generation (all from Perkin-Elmer) were used with Ar as plasma and purge gas for the cited analyzes; the optimized operating conditions are specified. The sample solution was injected into 3% HNO3 as carrier rather than HCl (to avoid formation of ArCl, which could interfere with the 75As signal) and the resulting stream was mixed with 0.2% NaBH4 solution The hydrides were entrained in Ar and, after passage through a gas - liquid separator, introduced into the plasma. Bismuth was used as internal standard. Detection limits ranged from 0.5 ng L-1 for Bi to 16 ng L-1 for 78Se; pre-reduction with KI improved the detection limits for As and Sb to 6 and 1.3 ng l-1, but impaired that for Hg. The coefficient of variation (n = 5) ranged from 0.5 to 1.6%. Results obtained for four reference water samples agreed with the certified values.
Sea Mass spectrometry Optimization Ultratrace Interferences Reference material FIAS-200

"Development Of An Atomic-fluorescence Spectrometer For The Hydride-forming Elements"
J. Anal. At. Spectrom. 1993 Volume 8, Issue 1 Pages 71-77
Warren T. Corns, Peter B. Stockwell, Les Ebdon and Steve J. Hill

Abstract: The covalent hydrides of As and Se were generated in a PSA 10.003 automated continuous-flow system (PS Analytical, Sevenoaks, UK) by merging the sample solution in 3 M HCl with 1.5% NaBH4 solution in 0.1 M NaOH; the mixture was passed through a gas - liquid separator, where the hydrides were entrained by Ar and passed through a hygroscopic membrane tube around which a dryer gas was circulated. The detection system incorporated an atomizer cell, a boosted-discharge hollow cathode lamp for excitation, and a solar blind photomultiplier. Of the four atom cell designs investigated, a simple design comprising a 10-cm borosilicate glass tube (5 mm o.d.; 3 mm i.d.) supporting a small Ar - H diffusion flame gave the best results and required no additional supply of H. Under optimized conditions (reported), which involved the use of a narrow-bandwidth interference filter (200±10 nm), the detection limits for As and Se were 0.1 and 0.05 µg L-1, respectively. The technique was used to analyze certified reference fresh and saline water samples with good accuracy and precision; preliminary reduction of As(V) was effected with KI, and of Se(VI) with HCl at 70°C.
River Sea Fluorescence Volatile generation Reference material Phase separator Optimization Interferences Volatile generation

"New Concept For Hydride-generation Technique: Electrochemical Hydride Generation"
J. Anal. At. Spectrom. 1993 Volume 8, Issue 3 Pages 397-401
Andreas Brockmann, Christiane Nonn and Alfred Golloch

Abstract: A miniaturized continuous-running cell with Pt anode and cathode compartments separated by a Nafion membrane and 2 M H2SO4 as anolyte plus diluted HCl or H2SO4 as catholyte were used. The anolyte was circulated after separation of liberated O and analyte hydrides were separated from the catholyte by a membrane gas - liquid separator. The very low catholyte flow enabled lower consumption of costly high-purity acids. The flow injection analytical system required sample volume of 100 µL. Tests with five reference materials (steels) indicated that Cr, Ni, Co and Cu did not interfere significantly with determination of As.
Alloy Spectrophotometry Electrochemical product conversion Interferences Reference material Nafion membrane

"Development Of A Proposed International Standard For Determining Arsenic In Workplace Air Using Hydride Generation Atomic Absorption Spectrometry"
J. Anal. At. Spectrom. 1994 Volume 9, Issue 3 Pages 273-280
Robert D. Foster and Alan M. Howe

Abstract: Air was sampled on a cellulose ester membrane filter and paper back-up pad previously conditioned with 1 M Na2CO3 in aqueous 5% glycerol. The exposed filters were treated at 175°C with 5 mL of concentrated HNO3 and 1 mL of concentrated H2SO4, the volume was reduced to 1 ml, 2 mL of H2O2 was added after cooling, and the mixture was heated until SO3 evolution ceased. The residue was dissolved in 10 mL of water, and 5 mL aliquots were treated with 12.5 mL of concentrated HCl and 2.5 mL of 10% KI solution and then with a stream (5 ml/min) of 0.2-2% NaBH4 solution in 0.1 M NaOH. As was determined at 197.2 or 193.7 nm (calibration graphs linear for 0-50 and 0-25 ng/ml of As, respectively) in both flow injection (FI) and continuous-flow (CF) systems. For 4.8-96 µg of As added on-filter, recoveries were >98.8% for both systems. For 10^-40 ng/ml of As, RSD of 1 and 3% were obtained for the CF and FI systems, respectively, at 197.2 nm. The limits of detection and determination were 0.3 and 1 ng/ml at 197.2 nm. Preliminary results from an inter-laboratory study are discussed.
Environmental Spectrophotometry Detection limit Cellulose ester

"Determination Of Selenium And Arsenic In Mineral Waters With Hydride-generation Atomic Absorption Spectrometry"
J. Anal. At. Spectrom. 1994 Volume 9, Issue 3 Pages 285-290
Marjan Veber, Ksenija Cujes and Sergej Gomiscek

Abstract: Water was filtered (0.45 µm) and acidified (HCl). For As, a 5-25 mL sample was treated with 4 mL of concentrated HCl and 1 mL each of aqueous 1% ascorbic acid and aqueous 20% KI, whereas for Se a 15 mL sample was treated with 10 mL of HCl and heated at 90°C for 12 min. After dilution to 50 ml, hydrides were generated [typical sample and reagent (1% NaBH4 solution in 1% NaOH) flow rates 10 ml/min] in a 75-100 cm x 1 mm i.d. reaction coil. After gas-liquid separation with Ar as carrier gas (40 l/h), continuous-flow determination was performed by electrothermal AAS. In situ pre-concentration was also performed with reagent and sample flow rates of 0.5 ml/min and an Ar flow rate of 5 l/h, the graphite surface being pre-conditioned by drying 50 µL of 10^-5% Pd solution Under continuous-flow conditions, standard-addition calibration was linear for 1-50 µg/l of As and Se with detection limits of 0.15 µg/l and RSD 5%. With pre-concentration, detection limits of 0.02 µg/l were obtained, with RSD of 2-16%. Recoveries of 10 µg/l of As and 0.5-1 µg/l of Se were satisfactory. Mg, Na and sulfate interfered.
Mineral Spectrophotometry Spectrophotometry Sample preparation Interferences Preconcentration

"Determination Of Arsenic, Chromium, Selenium And Vanadium In Biological Samples By Inductively Coupled Plasma Mass Spectrometry Using Online Elimination Of Interference And Preconcentration By Flow Injection"
J. Anal. At. Spectrom. 1994 Volume 9, Issue 5 Pages 611-614
Les Ebdon, Andrew S. Fisher and Paul J. Worsfold

Abstract: A 0.5 g portion of the biological material was digested with 3 mL of HNO3 and 2 mL of water for 16 h and then irradiated in a microwave oven at 300 W for 3 min. After cooling, 0.1 g of potassium persulfate was added and the digest was microwaved at 300 W for a further 2 min; H2O2 (1 ml) was then added and the digest was irradiated with a 150 W Xe lamp for 18 h to decompose arsenobentaine. The digest was diluted to 50 mL with Tris buffer (pH 9) following the addition of 3 mL of 60% NaOH. A 200 µL portion of this solution was injected into the water carrier stream (1.5 ml/min) of the flow manifold and passed through the alumina column (2.5 cm x 3 mm i.d.). The analytes were subsequently eluted from the column by injecting 200 µL of 1 M HNO3 into the carrier stream and determined by ICP-MS. The detection limits for V, Cr and As were 0.12, 0.6 and 0.9 µg/g. To achieve a detection limit of 1 µg/g for Se it was necessary to use an alternative procedure which involved the pre-concentration of 10 mL of digest. The recoveries of 60 ng/ml of Cr, Se and V and 600 ng/ml of As from a spiked biological reference material (Tort-1, lobster hepatopancreas) were 98-109%, respectively.
Biological material Mass spectrometry Reference material Preconcentration Interferences

"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.
Biological Urine Environmental Environmental Mass spectrometry Volatile generation Volatile generation

"Continuous Hydride Generation Low-pressure Microwave-induced Plasma Atomic Emission Spectrometry For The Determination Of Arsenic, Antimony And Selenium"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 4 Pages 311-315
Florian Lunzer, Rosario Pereiro-Garc&iacute;a, Nerea Bordel-Garc&iacute;a and Alfredo Sanz-Medel

Abstract: The direct coupling of on-line continuous hydride generation methods to low-pressure microwave-induced Ar and He plasmas, sustained in a surfatron, was evaluated for the determination of trace amounts of arsenic, antimony and selenium by atomic emission spectrometry. The effect of the hydrogen produced during the hydride generation step, the optimization of the operating conditions for He and Ar plasmas and the figures of merit of the analytical systems are given. Detection limits (3s) of 0.7, 0.9 and 4.1 ng ml-1 were obtained for As, Sb and Se, respectively, using an Ar plasma at 50 Torr (1 Torr = 133.322 Pa) and a power of 115 W. The relative standard deviations, calculated at the 50 ng ml-1 level, were in the range 3-4% for the three elements. Poorer detection limits were obtained for He than for Ar discharges (by about two to five times, depending on the emission line). Using an argon discharge, the method was applied successfully to the determination of As in sea-waters.
Sea Spectrophotometry Volatile generation Volatile generation

"Use Of Thiourea In The Determination Of Arsenic, Antimony, Bismuth, Selenium And Tellurium By Hydride Generation Inductively Coupled Plasma Atomic-emission Spectrometry"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 5 Pages 405-408
Hilde Uggerud and Walter Lund

Abstract: A study was made of thiourea as an agent for the pre-reduction and masking of interferences in the multi-element determination of arsenic, antimony, bismuth, selenium and tellurium by hydride generation inductively coupled plasma atomic emission spectrometry. Thiourea reduces arsenic and antimony from the pentavalent to the trivalent state, without preventing the determination of tetravalent selenium and tellurium. Thiourea also eliminates the interference from a number of metals in the determination of arsenic, antimony and bismuth, but it is not effective for selenium and tellurium.
Spectrophotometry Volatile generation Volatile generation

"Thermally Stabilized Iridium On An Integrated, Carbide-coated Platform As A Permanent Modifier For Hydride-forming Elements In Electrothermal Atomic Absorption Spectrometry. 3. Effect Of L-cysteine"
J. Anal. At. Spectrom. 1996 Volume 11, Issue 10 Pages 989-995
Dimiter L. Tsalev, Alessandro D'Ulivo, Leonardo Lampugnani, Marco di Marco and Roberto Zamboni

Abstract: The concentrations of cysteine (0.2-2%), NaBH4 (0.05-0.4%) and HCl (0.01-0.15M) for the generation of hydrides to be trapped in an ET atomizer coated with Ir/Zr (cf. Ibid., 1995, 10, 1003) in an automated flow injection hydride-generation system (Ibid., 1996, 11, 979) were optimized by a full 33 factorial design. Analytically useful conclusions are drawn, e.g., the presence of cysteine renders the pH adjustment of sample digests more critical.
Sample preparation Spectrophotometry Optimization Volatile generation Factorial design Volatile generation

"Thermally Stabilized Iridium On An Integrated, Carbide-coated Platform As A Permanent Modifier For Hydride-forming Elements In Electrothermal Atomic Absorption Spectrometry. 2. Hydride Generation And Collection, And Behaviour Of Some Organoelement Species"
J. Anal. At. Spectrom. 1996 Volume 11, Issue 10 Pages 979-988
Dimiter L. Tsalev, Alessandro D'Ulivo, Leonardo Lampugnani, Marco di Marco and Roberto Zamboni

Abstract: The Ir/W- and Ir/Zr-treated platforms (i.e., a permanent Ir modifier stabilized on a W- or Zr-treated platform) proposed previously (Ibid., 1995, 10, 1003) have been evaluated in direct ETAAS and in an automated flow injection hydride-generation ETAAS system in respect of the effects of the hydride-generation parameters, the purge-gas flow rate and the trapping temperature, and the long-term stability of the measurements, the behavior of some organometal species, and their applicability to real analyzes. It is concluded, inter alia, that the Ir/Zr-treated platforms are the more suitable for trapping the hydrides of As, Bi, Sb, Se, Sn and Te in an automated system, but that the Ir/W-treated platforms are the more suitable in direct ETAAS.
Spectrophotometry Optimization Volatile generation Volatile generation

"Effect Of Sample Volume On The Limit Of Detection In Flow Injection Hydride Generation Electrothermal Atomic Absorption Spectrometry"
J. Anal. At. Spectrom. 1998 Volume 13, Issue 1 Pages 17-21
Julian F. Tyson, Robert I. Ellis, Susan A. Mcintosh and Christopher P. Hanna

Abstract: The anal. performance of methods for the determination of hydride-forming elements has been improved recently by the development of procedures in which the hydride is trapped on the interior surface of a graphite furnace atomizer. The signal for a given concentration. increases with an increase in sample volume, and it is often implied that a decrease in the limit of detection may also be achieved by increasing the sample volume To evaluate this claim, a simple equation was derived which predicts the relationship between detection limit and sample volume when all the contributions to the blank are proportional to sample volume A time-based approach to the variation of sample volume was developed to ensure that the analyte introduced from reagent contamination was, in fact, proportional to sample volume Detection limits were measured for a series of sample volumes between 156 and 1560 µL. As the sample volume was increased, the detection limit improved significantly from 0.3 to around 0.05 µg/L up to a volume of about 500 µL. Between 500 and 1000 µL, a further improvement, to around 0.02 µg/L, was obtained, but for volumes larger than 1000 µL no further significant improvement was obtained. Good agreement between the predicted and experimental determined variations in detection limit with sample volume was obtained, and, thus, the underlying inverse proportionality of the relationship between detection limit and sample volume was confirmed. This rectangular hyperbolic relationship has practical consequences for the extent to which detection limits can be improved by increasing the sample volume, even when the blank is very low or zero.
Spectrophotometry Volatile generation Optimization Detection limit Timed injection Theory

"Electrochemical And Chemical Processes For Hydride Generation In Flow Injection ICP-MS: Determination Of Arsenic In Natural Waters"
J. Anal. At. Spectrom. 1998 Volume 13, Issue 12 Pages 1343-1346
Luis Fernando R. Machado, Antonio Oct&aacute;vio Jacintho, Amauri A. Meneg&aacute;rio, Elias A. G. Zagatto and Maria Fernanda Gin&eacute;

Abstract: A flow injection system involving hydride generation is proposed for the determination of arsenic in natural waters by inductively coupled plasma mass spectrometry. The manifold was designed to permit a direct comparison between chemical (NaBH4) and electrochemical (EcHG) processes for hydride generation, using sodium tetrahydroborate or a Nafion membrane, respectively. Reactions were carried out in different manifold sites, separation/transportation of the evolved gaseous species and quantification occurred in the same devices under similar conditions. Interferences by Co(ii), Ni (ii), Cu(ii), Zn(ii) and Pb(ii) were evaluated for both systems. When NaBH4 was used, addition of these species decreased the As signal, whereas for electrochemical arsine formation, the interference effects were dependent on the Pt cathode conditions. Interferences due to the above metals were modified when the cathode underwent Pb deposition. About 60 samples were run per h and the measurement precision for 10 µg/L As was characterized by an RSD <3%. A higher sensitivity was verified for NaBH4 (LOD = 0.05 µg/L As) than EcHG (0.2 µg/L As). Accuracy was assessed by using standard reference materials and spiked river water samples.
River Mass spectrometry Electrode Spectrophotometry Volatile generation Interferences Nafion membrane Electrochemical product generation Method comparison

"Automated Determination Of Arsenic And Selenium By Atomic Absorption Spectrometry With Hydride Generation"
Anal. Chem. 1984 Volume 56, Issue 12 Pages 2059-2063
Hisatake Narasaki and Masahiko Ikeda

Abstract: Hydrides are evolved in a Pyrex mixing tube (15 cm x 2 mm), collected in a gas - liquid separator up to an appropriate pressure, and then swept automatically into an a.a.s. furnace. Consumption of reagents is minimized. Introduction of trace water into the furnace prevents any decrease in sensitivity. The sensitivities for As(V) and Se(IV) were 0.01 and 0.004 absorbance unit per ng, respectively. Recoveries were quantitative when samples were pre-treated with Chelex 100 resin to remove interfering species. Biological standard reference materials (decomposed initially by HNO3, H2SO4 and HClO4) and river water samples were analyzed for As and Se; the water samples taken were 25 to 50 mL and 250 to 500 ml, respectively.
Food Plant River Spectrophotometry Chelex Interferences Reference material Phase separator

"Hydride-generation Atomic Absorption Spectrometry Coupled With Flow Injection Analysis"
Anal. Chem. 1985 Volume 57, Issue 7 Pages 1382-1385
Manabu Yamamoto, Makoto Yasuda, and Yuroku Yamamoto

Abstract: Flow injection analysis was combined with the gas-segmentation method described by Skeggs (Am. J. Clin. Pathol., 1957, 28, 311) for the determination of As, Sb, Bi, Se and Te. On synthetic samples the coefficient of variation were between 0.5 and 0.8% (n = 10) with detection limits between 0.04 and 0.3 ng. The results on NBS steel, wheat and rice flour, orchard leaves and coal fly ash were close to certified values and the differential determination of As and Sb in thermal water was possible. Tolerance limits for diverse ions are listed.
NIST 1633 NIST 1567 NIST 1568 NIST 1571 Rice Flour Wheat Flour Alloy Thermal Plant Industrial Spectrophotometry Reference material Segmented flow

"Inductively Coupled Plasma Mass Spectrometric Detection For Multielement Flow Injection Analysis And Elemental Speciation By Reversed-phase Liquid Chromatography"
Anal. Chem. 1986 Volume 58, Issue 12 Pages 2541-2548
Joseph J. Thompson and R. S. Houk

Abstract: The effluent from the HPLC column was converted into an aerosol by ultrasonic nebulization with desolvation for analysis on a Sciex ELAN model 250 ICP-MS instrument. Mobile phases used were methanolic solution of Na pentanesulfonate and tetrabutylammonium phosphate and the column (25 cm x 4.6 mm) contained Econosphere C18. Flow injection analysis coupled with ICP-MS was used to measure instrument response to a transient signal. Detection limits by flow injection analysis and by HPLC are reported for several elements. The separation and selective detection of As and Se species were shown; detection limits were ~0.1 ng (as the element) for all six species. Up to 15 elements could be determined in a single injection with multiple-ion monitoring. Isotope ratios measured on eluates containing Cd and Pb showed good accuracy, indicating that HPLC coupled with ICP-MS should allow speciation studies with stable tracer isotopes.
HPLC Mass spectrometry Spectrophotometry Speciation

"Membrane Gas-liquid Separator For Flow Injection Hydride-generation Atomic Absorption Spectrometry"
Anal. Chem. 1987 Volume 59, Issue 19 Pages 2446-2448
Manabu Yamamoto, Kazuko Takada, Takahiro Kumamaru, Makoto Yasuda, Shozo Yokoyama, and Yuroku Yamamoto

Abstract: A flow injection manifold with a membrane tube gas - liquid separator (illustrated) was applied in the determination of As in seawater. Thus, KI, HCl and ascorbic acid solution were added to the sample before injection of an aliquot (1 ml) into a stream of 1 M HCl and air (each 5 mL min-1). After being mixed with streams of Ar (100 mL min-1) and NaBH4 solution (3%; 1.5 mL min-1), the combined stream was passed through a micro-porous PTFE tube (o.d. 4 mm; i.d. 3 mm) inside a borosilicate glass tube (25 cm x 8 mm). The gaseous AsH3, H and Ar diffused through the PTFE tube walls and were passed to a heated silica cell at 950°C for the determination of As (Ibid., 1985, 57, 1382). In the determination of 3 ppb of As, the coefficient of variation was 2.5% (n = 10). There was little interference from up to a 2000- or 50,000-fold excess, respectively, of Pt or Ni.
Sea Spectrophotometry Gas diffusion Interferences Teflon membrane

"Hydride-generator System For A 1-kW Inductively Coupled Plasma"
Anal. Chem. 1989 Volume 61, Issue 3 Pages 285-288
J. David Hwang, Gary D. Guenther, and John P. Diomiguardi

Abstract: A continuous-flow hydride-generation system is described for use with a 1-kW ICP. Acidified sample solution and NaBH4 solution are pumped continuously by a multi-channel peristaltic pump into the hydride generator, wherein the sample solution flows down the outside of the NaBH4 tube and mixes and reacts with the NaBH4 solution as it emerges, thereby overcoming the dilution effects that occur in conventional hydride-generation systems. Also, smaller amounts of gaseous by-products are produced, thereby yielding a more stable plasma. Detection limits were 0.1, 1.4, 0.6, 0.3 and 1 ng mL-1 for As, Bi, Sb, Se and Sn, respectively, which are 30 to 700 times better than obtained with pneumatic nebulization.
Spectrophotometry Volatile generation Volatile generation

"Polymer-bound Tetrahydroborate For Arsine Generation In A Flow Injection System"
Anal. Chem. 1989 Volume 61, Issue 18 Pages 2079-2082
Solomon Tesfalidet and Knut Irgum

Abstract: Generation of arsine for subsequent AAS determination was carried out in a flow system using a column (10 cm x 6 mm) of Amberlyst A-26 (20 to 50 mesh) in the tetraborate form as a polymer-supported reducing agent. The analysis cycle comprised regeneration, washing and injection of HCl-acidified sample, and could be repeated every 4 min. The detection limit for As(III) was 1.5 µg L-1 (40 µL sample) and the calibration graph was rectilinear up to 100 µg l-1. Nickel, Co, Cu and Fe ions caused 10% signal degradation when present at concentration. of 2500 to 5000 mg L-1 when L-cystine was added as masking agent. The column could be used for at least 3 months without performance degradation.
Spectrophotometry Interferences Calibration Immobilized reagent Volatile generation Reduction column Volatile generation

"Measurement Of Vanadium, Nickel, And Arsenic In Seawater And Urine Reference Materials By Inductively Coupled Plasma Mass Spectrometry With Cryogenic Desolvation"
Anal. Chem. 1993 Volume 65, Issue 18 Pages 2468-2471
Luis C. Alves, Lloyd A. Allen, and R. S. Houk

Abstract: Addition of a small dose (2%) of H2 to the aerosol gas flow enhanced analyte signals by a factor of 2-3, which compensated for the loss of analyte signal that accompanied earlier efforts at cryogenic desolvation with inductively coupled plasma mass spectrometry (ICP-MS). Vanadium, nickel, and arsenic at microgram per liter levels in urine, river, and seawater reference materials were determined. The polyatomic ions ClO+, CaO+, and ArCl+, which normally cause severe overlap interferences for these elements, were attenuated to manageable levels by cryogenic desolvation. The samples were simply diluted with 1% HNO3 so that the chloride could be removed as HCl. The analytical results obtained for these standard reference materials agreed closely with the certified or recommended values. The detection limit ranges (3s) obtained were 10^-1000 ng L-1 for V, 0.03-20 µg L-1 for Ni, and 4-7000 ng L-1 for As in the original samples. The samples were introduced by flow injection to minimize clogging of the sampling orifice.
Sea Urine River Mass spectrometry Reference material Interface Interferences

"Metal Speciation By Supercritical-fluid Extraction With Online Detection By Atomic Absorption Spectrometry"
Anal. Chem. 1994 Volume 66, Issue 22 Pages 3900-3907
Jin Wang and William D. Marshall

Abstract: A silica flame-in-tube interface is described for the AAS detection of As, Cd, Cu, Mn, Pb, Se or Zn in the eluate from a SFE apparatus. It consisted of a heated optical tube placed within the optical beam of the spectrometer, a flame tube fitted with H2 and O2 gas entry ports and a sample introduction tube. The analyte metal in an aqueous medium was complexed in situ with tetrabutylammonium dibutyldithiocarbamate and the derivative was mobilized into supercritical CO2. The superheated extractor eluate was nebulized into the upper region of a diffuse flame in the interface flame tube and introduced into the optical tube for analysis. The optimal flame conditions were slightly reducing for aqueous and CO2 mobile phases but slightly oxidizing for a methanolic mobile phase. The detection limits of the metals were in the sub ng to low pg range when a standard was flow-injected into the mobile phase. The recoveries of 5 or 10 µg/ml of Cu, Mn and Pb were 92-94.4% with RSD of 0.1%; the RSD for the cumulative area under the AAS response curve was appreciably more variable. The differences in the rates of mobilization of analyte metal from different matrices was studied using fresh and freeze-dried bovine liver.
Liver Sample preparation Spectrophotometry Speciation Solvent extraction

"Microscale Flow Injection And Microbore High Performance Liquid Chromatography Coupled With Inductively Coupled Plasma Mass Spectrometry Via A High-efficiency Nebulizer"
Anal. Chem. 1995 Volume 67, Issue 24 Pages 4530-4535
Spiros A. Pergantis, Edward M. Heithmar, and Thomas A. Hinners

Abstract: A high-efficiency nebulizer has been used for coupling microscale now injection and microbore high performance liquid chromatography with inductively coupled plasma mass spectrometry (ICPMS). The microscale now injection system was configured to minimize band broadening between the injection valve and the nebulizer, and it was evaluated for now rates between 20 and 120 µL/min. Various materials, including certified reference materials, were analyzed for their arsenic and lead contents, Separation of arsenic species was carried out on microbore liquid chromatography columns. The absolute detection limits (femtogram range) for various arsenic compounds were excellent compared with those obtained previously by using conventional column (1 mL/min eluent now) high performance liquid chromatography/inductively coupled plasma mass spectrometry, Other advantages of this system include use of small sample volumes (less than or equal to 1 µL), the resulting minimization of sample matrix introduction into the plasma, and reduced waste generation compared with conventional ICPMS sampling systems. (31 references)
Sea HPLC Mass spectrometry Optimization Reference material Simplex Speciation

"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.
Biological Environmental Sample preparation Spectrophotometry Interferences Nebulizer Reference material

"Study Of Some Interfering Processes In The Arsenic, Antimony And Selenium Determination By Hydride-generation Atomic Absorption Spectrometry"
Fresenius J. Anal. Chem. 1993 Volume 346, Issue 6-9 Pages 622-626
Maciej Walcerz, Ewa Bulska and Adam Hulanicki

Abstract: A twin-channel continuous-flow apparatus was used to determine at what stage interference was occurring in the cited analysis. Each channel had its own gas-liquid separator and the two gas phases, with Ar (300 ml/min) as carrier gas, were united just before the furnace. In the single-channel mode, one channel carried the analyte with increasing concentration. of interferent; the second channel contained a blank solution of 2 M HCl. In the twin-channel mode, one channel contained the analyte and the other the interferent. If the results in the two modes were similar, the interference occurred in the gas phase, while differences indicated some interference in the liquid phase. Studies were carried out using analyte concentration. of 50 µg/l and interferent cocncn. of 0.2-50 mg/l. The reducing solution was 0.5% NaBH4 solution in 0.1 M NaOH. The effects of As, Bi, Pb, Sb, Se, Sn and Te (as interferents) on As, Sb and Se (as analytes) are reported. Spectral interference by As and Sb in the 190-235 nm region was caused by molecular bands.
Spectrophotometry Interferences

"Determination Of Arsenic In The Presence Of High Copper Concentrations Using Flow Injection Analysis - Hydride[-generation] Atomic Absorption Spectrometry"
Fresenius J. Anal. Chem. 1993 Volume 346, Issue 6-9 Pages 683-685
C. Schmidt and M. Bahadir

Abstract: Landfill waste water from polymer shredding waste of electrical cable (10 ml) was mixed with 5.5% hydroxylammonium chloride solution (1 ml) to reduce Cu(II) to Cu(I) and with 37% HCl (3 ml) and a KI-ascorbic acid reagent to reduce As(V) to As(III) and ppt. CuI and PbI2. After centrifugation, a 0.5 mL portion of the solution was injected into 4.35% HCl as carrier and the AsH3 generated with NaBH4 was determined by AAS. The solution contained 10 g/l of Cu(II), 0.15 g/l of Pb(II), 25 mg/l of Fe(III) and 0.4 g/l of Ni(II). Down to 1 µg/l of As could be detected in such solution
Metal Waste Spectrophotometry Speciation Volatile generation Volatile generation

"Continuous-flow Hydride Generation For The Preconcentrationand Determination Of Arsenic And Antimony By GFAAS"
Fresenius J. Anal. Chem. 1994 Volume 350, Issue 12 Pages 662-666
Maciej Walcerz, Slawomir Garbo, Ewa Bulska and Adam Hulanicki

Abstract: A method has been developed for the determination of arsenic and antimony at sub-ppb level using hydride pre-concentration inside the graphite furnace. The influence of the quality of the graphite surface, of its modification with palladium coating and of the ways of introducing hydride into the furnace on the analytical signal is discussed. After optimization of system parameters, detection limits of 25 and 36 pg were obtained for arsenic and antimony. Characteristic masses (for arsenic and antimony, respectively) were 31 and 33 pg/0.0044 A s for direct injection GFAAS and 69 and 57 pg/0.0044 A s for hydride in situ pre-concentration and atomization in the palladium coated graphite tube. Therefore the overall efficiency of the hydride generation and trapping was estimated to be 45 and 58% for arsenic and antimony, respectively
Spectrophotometry Preconcentration Volatile generation Volatile generation

"Speciation Of Arsenic In Water Samples By High Performance Liquid Chromatography-hydride Generation-atomic Absorption Spectrometry At Trace Levels Using A Post-column Reaction System"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 3 Pages 344-351
J. Stummeyer, B. Harazim and T. Wippermann

Abstract: Anion-exchange HPLC has been combined with hydride generation - atomic absorption spectrometry (HG-AAS) for the routine speciation of arsenite, arsenate, monomethylarsenic acid and dimethylarsinic acid. The sensitivity of the AAS-detection was increased by a post-column reaction system to achieve complete formation of volatile arsines from the methylated species and arsenate. The system allows the quantitative determination of 0.5 g/l of each arsenic compound in water samples. The stability of synthetical and natural water containing arsenic at trace levels was investigated. To preserve stored water samples, a method for quantitative separation of arsenate at high pH-values with the basic anion-exchange resin Dowex 1 x 8 was developed.
Water HPLC Spectrophotometry Post-column derivatization Volatile generation Speciation Volatile generation

"A FIA System For Arsenic(III)/arsenic(V) Determination With Electrochemical Hydride Generation And AAS Detection"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 7-8 Pages 866-869
Dirk Schauml&ouml;ffel and B. Neidhart

Abstract: Total inorganic As in the carrier stream (1 M H2SO4, 5.4 ml/min) was determined by mixing with 10% L-cysteine solution (1 ml/min), heating in a water bath (95°C) for 40 s and then cooling in ice. The stream passed to the cathode channel of a flow-through cell (described) in which As was converted into AsH3, which was carried in a stream of Ar for determination by AAS. The response was linear for 5-50 µg/l of As(III), with a detection limit of 0.4 µg/l, for 1 mL samples.
Spectrophotometry Electrochemical product generation Heated reaction

"Differential Determination Of Arsenic(III) And Total Arsenic With L-cysteine As Prereductant Using A Flow Injection Non-dispersive Atomic Absorption Device"
Fresenius J. Anal. Chem. 1996 Volume 355, Issue 3-4 Pages 324-326
X. Yin, E. Hoffmann and C. L&uuml;dke

Abstract: The reduction of 2 µg/l As(V) to As(III) was complete within 60, 40 or 20 min at L-cysteine concentrations of 0.04, 0.08 or 0.16M, respectively, at room temperature in 0.029 M HNO3 or 0.024 M HCl. After flow injection hydride generation, the sample was atomized in a quartz tube at 800°C for analysis using a non-dispersive AAS device. As was determined at 1 sample/min with a detection limit of 0.01 µg/l for a 0.5 mL sample. Of the other elements tested, only Se(IV) and Bi(III) interfered at 150-fold excess. The RSD was 1.2% (n = 10). The method was applied to the speciation of As in river, tap and mineral waters. The As(III) was determined directly in 0.166 M acetic acid and the total As by the above technique.
Mineral Water River Spectrophotometry Interferences Speciation

"Interferences By Transition Metals And Their Elimination By Cyanide As A Complexing Agent In The Determination Of Arsenic Using Continuous-flow Hydride-generation ICP-AES System"
Fresenius J. Anal. Chem. 1996 Volume 356, Issue 5 Pages 331-334
. Jamoussi, M. Zafzouf and B. Ben Hassine

Abstract: The suppressing effects of ppm amounts of Cu, Pb, Co, Au, Pd, and Ni in the determination of As by hydride-generation (HG) ICP-AES were eliminated by use of cyanide as masking agent. In the determination of As by continuous-flow HG ICP-AES, 0.1 M KCN (2.5 ml/min) was mixed with 2% NaBH4 in 1% NaOH (2.5 ml/min), and the mixture was combined with the sample stream (2.75 ml/min) in a V-shaped reaction vessel, and the resulting AsH3 was swept by Ar, via a water condenser, into the ICP source (operating conditions tabulated) and the intensity of the As emission was recorded at 279.55 nm. Under the cited conditions up to 100 µg/ml of the interfering elements could be tolerated. The limit of detection was 0.82 ng/ml of As, and for 50 ng/ml of As the RSD was 1.3% (n = 10).
Spectrophotometry Interferences Volatile generation Volatile generation

"Investigation Of The Automated Determination Of Arsenic, Antimony And Bismuth By Flow Injection Hydride Generation Using In Situ Trapping On Stable Coatings In Graphite-furnace Atomic Absorption Spectrometry"
Fresenius J. Anal. Chem. 1996 Volume 356, Issue 7 Pages 435-444
H. O. Haug and Y. -p. Liao

Abstract: The elements were determined in low-alloy steel reference materials, which were dissolved in aqua regia at 90°C over 3 h. Solutions were diluted to 100 mL with 1 M HNO3 and portions treated with 1% L-cysteine in 0.1 M HNO3 for flow injection hydride generation by reaction with alkaline 0.5% NaBH4 and use of 0.1 M HCl (2.8 ml/min) as carrier solution. The liberated hydrides were measured by GFAAS trapping adsorption in situ on to Zr-coated graphite tubes (or Ir-coated for Sb). Hydride introduction was at 700-750°C (As), 450°C (Sb) or 300-400°C (Bi) and atomization at 2100-2400°C (As) or 2100°C (Sb or Bi) and measurements were at 197.2 (As), 217.6 (Sb) or 223.1 nm (Bi) with Zeeman background correction (As and Sb) or with no correction or deuterium correction (Bi). Hydride generation efficiencies were >98% for Sb and >95% for Bi and respective trapping efficiencies were 91% and 56%. Detection limits were 0.015, 0.010 and 0.027 ng for As, Sb and Bi hydrides, respectively, and corresponding precisions of determination were
Alloy Sample preparation Spectrophotometry Volatile generation Reference material Volatile generation

"Flow Injection Atomic Absorption Spectrometry For The Standardization Of Arsenic, Lead And Mercury In Environmental And Biological Standard Reference Materials"
Fresenius J. Anal. Chem. 1997 Volume 357, Issue 7 Pages 827-832
Gautam Samanta and D. Chakraborti

Abstract: Environmental and biological CRM were digested (details given). For the determination of Pb, prepared samples (50 µL) were injected into a carrier stream (1 ml/min) of 9% ammonium persulfate in 6% HNO3, which merged with a reducing stream (1 ml/min) of 8% NaBH4 in 1% NaOH then passed through a gas-liquid separator. A N2 flow (100 ml/min) carried hydrides to an AAS instrument for determination at 283.3 nm using an air-acetylene flame. For the determination of As, the carrier stream was 5 M HCl, the reducing stream was 1% NaBH4 containing 0.5% NaOH, the N2 flow rate was 200 ml/min and measurement was at 193.7 nm. For the determination of Hg, the carrier stream was 4% NaOH, the reducing stream was 0.5% SnCl2 and 0.035% L-cysteine in 1.5% H2SO4, the N2 flow rate was 50 ml/min and measurement was at 253.7 nm. A flame was not required for Hg determinations. The detection limits were 2 µg/l Pb, 1.8 µg/l As and 1.5 µg/l Hg, the quantitation limits were 7, 6 and 5 µg/l, respectively, and the corresponding RSD (n = 10) were 4%, 3% and 2%. Calibration ranges and recoveries are not stated. The sample throughput was 80/h in all cases. Results are tabulated for 12 CRM. The effects of interferents are also discussed. Results of a thorough study and application of flow injection atomic absorption spectrometry for the determination of As, Pb and Hg in parts per million to subparts per billion levels in environmental and biological samples have been described. Various standard reference materials from the National Bureau of Standards, USA, the National Institute of Standards and Technology, USA, the Community Bureau of Reference, Brussels, Belgium and the National Institute for Environmental Studies, Japan and Standard Chinese river sediment were used. By flow injection hydride generation AAS the standard reference materials were analyzed for As and Pb. Mercury was determined by cold vapor flow injection AAS from environmental and biological standard reference materials. The technique is fast, simple and highly sensitive. It takes only 30 s for each analysis from the digested solution. The detection limits of As, Pb and Hg are 1.8 µg L-1, 2.0 µg L-1 and 1.5 µg L-1, respectively. The results show good agreement with the certified values. 48 References
River Biological Water Ground Spectrophotometry Sample preparation Spectrophotometry Reference material Interferences PPB Volatile generation Volatile generation

"Comparison Of Sample Digestion Procedures For The Determination Of Arsenic In Certified Marine Samples Using The FI-HG-AAS-technique"
Fresenius J. Anal. Chem. 1997 Volume 357, Issue 7 Pages 817-821
G. Damkr&ouml;ger, M. Grote, E. Jan&szlig;en

Abstract: For dry ashing, 0.2 g CRM (cod and mussel) were homogenized with 3 g MgO and 40 mL 0.75 M magnesium nitrate, evaporated at 130°C for ~3 h to near-dryness and ashed at 550°C overnight. The ash was dissolved by the dropwise addition of 25 mL 32% HCl and the solutions were diluted to 100 mL with water. For high-pressure ashing, 0.2 g mussel CRM and 0.16 g cod CRM were each mixed with 2 mL 65% HNO3 and 4 mL 30% H2O2 and then ashed with temperature programming from 50-70°C in 30 min, to 120°C in 30 min, then to 300°C (held for 80 min) in 15 min. The resulting clear solutions were diluted to 20 mL with water. For microwave digestion, 0.25 g mussel CRM and 0.2 g cod CRM were each mixed with 3 mL 65% HNO3, and 2 mL 30% H2O2 and irradiated at 250 W for 1 min, left to stand for 1 min, then irradiated at 250 W for 1.5 min, 450 W for 3 min, 850 W for 5 min and 250 W for 1 min. The resulting solutions were diluted to 25 mL with water. The solutions were analyzed for As by flow injection hydride-generation AAS (details given). Mean recoveries of As from mussel and cod were 13% and 2%, respectively, by microwave digestion and 56% and 25%, respectively, by high-pressure ashing. The dry ashing method gave quantitative recoveries from both CRM. Nitrite interference was overcome by the addition of an amino sulfuric acid (350 mM).
Muscle Liver NRCC DORM-1 NRCC NOAA-K Sample preparation Sample preparation Sample preparation Spectrophotometry Interferences Method comparison Reference material

"Sequential Determination Of Tin, Arsenic, Bismuth And Antimony In Marine Sediment Material By Inductively Coupled Plasma Atomic Emission Spectrometry Using A Small Concentric Hydride Generator And L-cysteine As Prereductant"
Fresenius J. Anal. Chem. 1998 Volume 361, Issue 2 Pages 155-157
Y.-L. Feng A, H.-Y. Chen A, H.-W. Chen A, Li-Ching Tian

Abstract: A hydride generation system using a small concentric hydride generator combined with inductively coupled plasma atomic emission spectrometry (ICP-AES) was established to determine tin, arsenic, bismuth and antimony in a marine sediment material with L-cysteine as a pre-reductant. Influences of concentrations of three kinds of acids (HCl, HNO3 and HClO4), L-cysteine, and sodium tetrahydroborate(III) as well as sodium hydroxide were investigated. The interferences from transition ions were found to be insignificant for determination of the four elements in presence of L-cysteine. Under optimized conditions the detection limits were 0.6 ng/mL for arsenic(III), 0.8 ng/mL for antimony(III), 1.7 ng/mL for tin(IV), and 1.2 ng/mL for bismuth(III). The method was applied to determine the four elements in standard marine sediment materials and the results were in agreement with certified values.
Marine Mass spectrometry Phase separator Volatile generation Apparatus

"Electrolytic Hydride Generation Electrothermal Atomic Absorption Spectrometry - In Situ Trapping Of As On Different Pre-conditioned End-heated Graphite Tubes"
Fresenius J. Anal. Chem. 1998 Volume 361, Issue 6-7 Pages 733-737
E. Denkhaus A, A. Golloch A, T. U. Kampen A, M. Nierfeld A, U. Telgheder

Abstract: An automated analytical system for the determination of As combining an electrolytic hydride generator and a graphite furnace atomic absorption spectrometer has been developed. To investigate the trapping efficiency of permanent modifiers, the end-heated graphite tubes have been impregnated with Ir and mixed Pd/Ir pre-reduced modifiers, respectively, or pre-coated with Ir by electron beam evaporation under high vacuum. Furthermore, the influence of the modifier mass on the shape of the absorption signal has been studied and the performance of the modifier has been discussed. Using the pre-coated graphite tube the calculated detection limit (3s criteria ) for As was 3 pg and 15 ng/L (200 wL sample volume, two pre-concentration steps) for the absolute mass and the concentration, respectively. The long-term stability of the permanent modifiers and their physical and or chemical changes during the lifetime of the tube have been observed.
Spectrophotometry Electrochemical product generation

"Determination Of Arsenic, Selenium And Mercury In An Estuarine Sediment Standard Reference Material Using Flow Injection And Atomic Absorption Spectrometry"
Microchim. Acta 1995 Volume 118, Issue 3-4 Pages 163-175
Rajananda Saraswati, Thomas W. Vetter and Robert L. Watters Jr.

Abstract: Sediment (0.3 g) was digested with 5 mL each of concentrated H2SO4 and HNO3 and 2 mL concentrated HCl in a microwave oven (program tabulated), excess HNO3 was removed and the samples were diluted to 200 mL with 2% HCl. For Hg determination, a similar method was followed using 10 mL concentrated HNO3 (program tabulated) and the digests were mixed with 0.75 mL 1% K2Cr2O7 and diluted to 100 mL with 1% H2SO4. Reduction of As and Se was performed as described previously (Analyst, 1995, 120, 95) prior to analysis by flow injection AAS at 193.7 and 196 nm, respectively (loc. cit.; operating conditions tabulated). To determine Hg, samples (500 µL) were injected into a carrier stream (10 ml/min) of 3% HCl, mixed with 1% SnCl2 (6 ml/min) in an 11 cm reaction coil and the Hg vapor was separated and carried in Ar (80 ml/min) to the absorption cell for AAS at 253.7 nm. The calibration graphs were linear for up to 20, 25 and 6 ng/ml As, Se and Hg, respectively, and the corresponding detection limits were 0.15, 0.17 and 0.15 ng/ml. The RSD are tabulated. The results agreed with those obtained using reflux column digestion; the sample preparation time was 1-2 h.
Estuarine Sample preparation Spectrophotometry Spectrophotometry Reference material Method comparison

"The Use Of Reference Materials In The Fossil Fuels Quality Control"
Microchim. Acta 1996 Volume 123, Issue 1-4 Pages 217-230
Maurizio Bettinelli, Sandro Spezia, Umberto Baroni and Gabriele Bizzarri

Abstract: Quality control procedures used for the determination of trace elements in fuel oil and coal are described. Two standard reference materials (NIST 1632a and 1632b) were used to evaluate the accuracy in the determination of As, Hg and Se in coal by flow injection (FI) hydride-generation (HG) AAS and FI HG ICP-MS after microwave solubilization (Anal. Chim. Acta, 1989, 225, 159). RSD over 2 years were 10% for As, 8.11% for Se and 15% for Hg. The use of real fuel oil samples to compare results obtained for the determination of Ni and V by NAA, ICP-MS, ETAAS and ICP-AES in 54 laboratories is discussed. Similarly, the use of real samples to detect significant bias in the determination of As, Hg and Se in coal using various techniques (NAA, FI HG AAS, FI HG ICP-MS, ETAAS) is discussed.
NIST 1632 Oil Sample preparation Spectrophotometry Spectrophotometry Mass spectrometry Mass spectrometry Reference material Method comparison

"Correcting Measurement Errors Using Reference Materials In Method Validation"
Microchim. Acta 1996 Volume 123, Issue 1-4 Pages 231-240
Jytte Molin Christensen

Abstract: The correction of measurement errors in method evaluation studies is discussed. In the first example, reference materials were used in a method evaluation study of Pb in blood using two different AAS instruments (Perkin-Elmer Models 4100 and 5100) with Zeeman background correction. The number of method evaluation function (MEF) samples was insufficient for the MEF slopes to be used for correction of systematic errors. Secondly, a method evaluation study on valproate in plasma using an EMIT assay (SYVA) on a COBAS MIRA S is described; systematic error above 300 mM valproate was corrected for using the slope of the MEF. Thirdly, correction during evaluation of a FIA AAS method to determine As compounds and their metabolites in urine is described. The use of reference materials to determine performance characteristics during method development is discussed.
Urine Spectrophotometry Reference material

"Determination Of Arsenic And Selenium By Hydride Generation Atomic Absorption Spectrometry Using A Gas-liquid Separator And A Dehydration Trap"
Microchem. J. 1996 Volume 53, Issue 1 Pages 18-25
Hisatake Narasaki and Jun-Yan Cao

Abstract: Biological material (0.25 g) was allowed to stand overnight in 3 mL concentrated HNO3, 0.5 mL concentrated H2SO4 and 1 mL 60% HClO4 were added and the mixture was digested under low heat until the fumes of HClO4 subsided. The digests, including siliceous residues, were transferred to a Pt dish with water and evaporated to 2 mL. The residues were dissolved with 5 mL 46% HF, 1 mL 9 M H2SO4 was added and the solution was concentrated to 2 mL. The pH was adjusted to 3.5 with 1 M NH3 and applied to a SPE column (35 cm x 10 mm i.d.) packed with 10 cm Chelex 100 chelating ion-exchange resin and the column was washed with 2 x 10 mL water. For the analysis of As; the column effluents were diluted to 100 mL with water and a 10 mL portion was mixed with 5 mL 6 M HCl. Portions of both acid solutions were introduced into the flow injection hydride generation system (schematic shown) and mixed with a stream of 2% sodium tetrahydroborate(III) solution in a Pyrex mixing coil (16 cm x 2 mm i.d.). The hydride generated was collected in a gas-liquid separator, dehydrated in a dehydration trap and swept into an electrically heated furnace with a carrier stream of N2 (2.5 l/min) by manipulating electromagnetic relays and timers (operating details given). The atomized As and Se species were detected at 193.7 and 196 nm, respectively, by AAS. The detection limits were 0.6 and 1 ng/ml, respectively. Tolerance levels to 10 foreign ions are listed. The method was applied to the analysis of five NIST Standard Reference materials (listed). Results agreed well with certified values.
Hepatopancreas Rice Flour Wheat Flour Oyster Plant NIST 1566 NIST 1567 NIST 1568 NIST 1571 NRCC TORT-1 Spectrophotometry Reference material Chelex

"Soluble And Particulate Metals In The Adige River"
Microchem. J. 1998 Volume 59, Issue 1 Pages 19-31
A. Bortoli, E. Dell'Andrea, M. Gerotto, M. Marchiori, M. Palonta and A. Troncon

Abstract: The concentrations of 10 metals (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn) were monitored over a one-year period in the waters of the lower Adige River, Italy. Concentrations in the dissolved and particulate phases were measured, thus constructing a database on metal variability. The concentrations. of Cd, Cr, Cu, Mn, Ni, and Pb in these water samples are too low to be directly determined by flame atomic absorption spectrometry or graphite furnace atomic absorption spectrometry. In this work, Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS) or GFAAS after online pre-concentration. and following solvent elution with a flow injection analysis system (FIAS). The eluted samples were also dried in a vacuum container and restored to a small volume with concentrated HNO3 and Milli-Q water for anal. by ICP-MS or GFAAS. The concentrations of soluble Cd, Fe, and Mn and particulate As, Cr, Cu, Pb, and Zn are well correlated with seasonal variability (P < 0.01). Dissolved As and Fe are well correlated (P < 0.01), and with respect to the particulate phase, good correlations are observed between Pb, Cd, and Cu.
River Mass spectrometry Spectrophotometry Sample preparation Preconcentration Solvent extraction

"Determination Of Trace Elements In Power Plant Emissions By Inductively Coupled Plasma Mass Spectrometry: Comparison With Other Spectrometric Techniques"
Microchem. J. 1998 Volume 59, Issue 2 Pages 203-218
M. Bettinelli, S. Spezia, U. Baroni and G. Bizzarri

Abstract: Particulate matter in stack effluents of coal-fired plants was collected with an isokinetic probe nozzle suitable for (a) total particulate samplings on membrane filters and (b) sampling with a low volume 10-stage single orifice cascade impactor plus a backup filter. A microwave digestion method using an acid mixture of HNO3-HCl-HF in a closed vessel was developed for the determination of major, minor, and trace elements in very small amounts of sample. Analyses were carried out by inductively coupled plasma mass spectrometry (ICP-MS). A recovery study was conducted using multielemental standard solutions, NIST1633a Trace Elements in Coal Fly Ash and NIST 1648 Urban Particulate Matter, to examine the capabilities of the method. The results for real samples dissolved by this procedure were compared with results obtained by instrumental neutron activation anal., graphite furnace atomic absorption spectrometry, and flow injection hydride generation atomic absorption spectrometry. The anal. capabilities of ICP-MS make it one of the techniques of choice for the determination of trace elements in emission particulate matter collected in different granulometric particle sizes.
Industrial NIST 1633 NIST 1648 Mass spectrometry Sample preparation Method comparison Reference material

"Utilization Of Dual Phase Gas Diffusion Flow Injection Analysis With A Mass Spectrometer As A Detector"
Anal. Lett. 1988 Volume 21, Issue 9 Pages 1619-1631
J. S. Canham; G. E. Pacey

Abstract: Hydrides of As and Se were generated in aqueous solution from which they diffused through a Goretex micro-porous membrane (0.45 µm pore size) into dry He for detection by MS. No mixed hydrides were observed. The detection limit for As was ~500 ng; that for H2Se was 1 µg. Tin and Sb were easily detected and did not interfere.
Mass spectrometry Gas diffusion Goretex Volatile generation Interferences Kinetic Volatile generation

"Use Of A Surfactant In The Determination Of Arsenic By Flow Injection Hydride-generation Atomic Absorption Spectrometry"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1859-1866
Robert I. Ellis and Julian F. Tyson*

Abstract: For concentrations of As of 5-30 µg/l, no beneficial effect of the presence of didodecyldimethylammonium bromide vesicles on either sensitivity or recovery was observed.
Spectrophotometry

"Determination Of Arsenic In Gold By Flow Injection Inductively Coupled Plasma Mass Spectrometry With Matrix Removal By Reductive Precipitation"
Spectrochim. Acta B 1996 Volume 51, Issue 14 Pages 1823-1827
Paul Becotte-Haigha, Julian F. Tysona,*, Eric Denoyerb and Michael W. Hindsc

Abstract: Gold was dissolved in HCl/HNO3 (3:1) with heating until the volume had been reduced by half, then 1% HCl was added until the Au concentration was 0.05% (w/w), and a 40 g portion of this solution was treated with 20 mL each of 10% ascorbic acid/10% KI solution and HCl and diluted to 200 g. The precipitate was collected on glass wool and dissolved in aqua regia, and the solution was diluted to 200 mL. A 0.1 mL portion of this solution was diluted to 100 g, and a 0.5 mL portion was injected into a carrier stream of 10% HCl (10 ml/min) that then merged with a stream of NaBH4 solution in 0.05% (w/w) NaOH (5 ml/min). The gas-liquid separator was a slight modification of that described by Welz and Schubert-Jacobs (At. Spectrosc., 1991, 12, 91). The operating conditions of the ICP mass spectrometer are tabulated. For 29.7 µg/g of As found in gold the standard deviation (n = 4) was 0.972 µg/g; the results agreed with those obtained by GFAAS and by another ICP-MS method.
Metal Mass spectrometry Precipitation Method comparison Phase separator

"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).
Water River Sea Environmental Mass spectrometry Interferences Standard additions calibration Volatile generation Volatile generation

"Flow Injection Thermospray Sample Deposition For Electrothermal-atomization Atomic Absorption Spectrometry"
Spectrochim. Acta B 1989 Volume 44, Issue 6 Pages 571-579
P. C. Bank, M. T. C. de Loos-Vollebregt and L. de Galan

Abstract: The flow injection thermospray introduction system described previously (Ibid., 1988, 43B, 983) has been modified to obtain more reproducible sample deposition on to the wall of a graphite-tube atomizer. Under optimum conditions, viz, a sample flow rate of 0.7 mL min-1, a thermospray vaporizer temperature of 300°C and a deposition temperature of 120°C in the graphite tube, the sensitivities for Ag, Al, As, Au, Cd, Co, Mn, Pb, Ru and V were identical with those obtained by conventional graphite-furnace AAS. The area of spray-deposited material formed on the wall of the graphite tube is independent of sample volume (unlike conventional manual injection), and thus the flow injection thermospray system can be used over wide analytical ranges. Solutions containing up to 2% of NaCl could be injected without plugging of the thermospray vaporizer capillary.
Spectrophotometry Optimization Interface

"Hydride-generation Flow Injection Using Graphite Furnace Detection - Emphasis On Determination Of Tin"
Spectrochim. Acta B 1992 Volume 47, Issue 5 Pages 701-709
Zhang Li, Susan McIntosh, Glen R. Carnrick and Walter Slavin*

Abstract: Hydride-forming analytes were separated from large volume of matrix by trapping the hydrides on a Pd-coated L'vov platform at low temperature before analysis by AAS. The Pd-treated stabilized-temp. platform furnace was used for in situ trapping and atomization of the analyte, and was at least 80% efficient for As, Bi, Ge, Sb, Se, Sn and Te. The method was tested by determining Sn in steel, river sediment, orchard leaves and bovine liver standard reference materials. The detection limit for Sn was 7 ng l-1, and the coefficient of variation was 31.5% at the 1.0 ng level. Other hydride-forming elements did not interfere.
Alloy River Plant Liver NIST 1571 NIST 1577 NIST 1645 Spectrophotometry Interferences Volatile generation Reference material Volatile generation

"Formation And Interpretation Of Double Peaks In Flow Injection Hydride Generation Atomic Absorption Spectrometry"
Spectrochim. Acta B 1992 Volume 47, Issue 5 Pages 645-658
Bernhard Welz* and Tiezheng Guo

Abstract: The formation of double peaks and time shifts for second peaks were observed in flow injection hydride-generation AAS at low quartz-tube atomizer temperature and high analyte concentration. and in the presence of an insufficient supply of O. The phenomena could be explained satisfactorily by H-radical depletion, which results in the formation of Sb and As mono- and di-hydrides instead of atoms. These hydrides are thermally decomposed to the element and retained in the heated quartz tube, and could be re-volatilized and atomized by reaction with H radicals. The observations strongly support the H-radical mechanism for hydride atomization in an externally heated quartz tube. Under conditions which are nonoptimum, such as low quartz tube atomizer temps., insufficient oxygen supply and excessively high analyte element concentrations., double peaks and a shift in time of the second peak may be observed in flow injection hydride generation atomic absorption spectrometry. These phenomena can be explained satisfactorily by a hydrogen radical depletion which results in the formation of mono- and di-hydrides of antimony and arsenic instead of atoms. These mono- and di-hydrides are thermally decomposed to the element and retained in the heated quartz tube and may be revolatilized and atomized by reaction with hydrogen radicals. The phenomena described in this work strongly support the hydrogen radical mechanism of atomization of arsine and stibine in an externally heated quartz tube atomizer.
Spectrophotometry Doublet peaks Volatile generation Volatile generation

"Determination Of Arsenic In A Nickel Alloy By Flow Injection Hydride Generation Atomic Absorption Spectrometry"
Spectrochim. Acta B 1992 Volume 47, Issue 9 Pages 1065-1073
C. P. Hanna and J. F. Tyson*, S. G. Offley

Abstract: The cited method did not require matrix removal and pre-reduction of As(V) to As(III) prior to arsine generation. The system was optimized to give better sensitivity and interference tolerance. It was possible to achieve full recovery of As(V) from a solution containing 5 ng mL-1 of As(V) in the presence of 60 µg mL-1 of Ni. Up to 60 injections per h can be made with a detection limit of 0.5 ng mL-1 of As(V) in a 500 µL sample. The coefficient of variation for 10 ng mL-1 was 3.5%. The development of a method for the direct determination of trace As quantities in Ni alloy digests, by flow injection hydride generation atomic absorption spectrometry, is described. An optimization study of the manifold and chemical parameters produced system performance, in terms of tolerance of the Ni matrix and sensitivity, such that matrix removal and pre-redn. of As(V) to As(III) prior to arsine generation were eliminated. Full recovery of the As(V) signal from a solution containing 5 ng mL-1 in the presence of 60 µg mL-1 Ni was obtained. Validation of the method was achieved by analyzing a British Chem. Standard (BCS) Certified Reference Material (CRM) #346 IN Ni alloy containing As at a concentration. of 50 µg g-1. Following dissolution in nitric and hydrofluoric acids by a microwave assisted procedure, the only subsequent preparation required was dilution by the appropriate factor. Up to 60 injections h-1 may be made, with a detection limit of 0.5 ng mL-1 As (250 pg abs.) as As(V) in a 500 µL sample. The peak height characteristic concentration. is 0.46 ng mL-1, with a relative standard deviation of 3.5% for a 10 ng mL-1 As(V) standard (n = 6).
Alloy BCS 346 Sample preparation Spectrophotometry Optimization Interferences Reference material

"Flow Injection Hydride Generation Determination Of Arsenic With In Situ Concentration In A Graphite Furnace"
Spectrochim. Acta B 1992 Volume 47, Issue 12 Pages 1403-1410
Y. An, S. N. Willie and R. E. Sturgeon

Abstract: Various elemental interferences in the determination of As using flow injection hydride generation were evaluated; a diagram of the apparatus used is given. Acidified sample solution and NaBH4 (both at 4.6 mL min-1) were merged and passed into a reaction tube. The pump was turned off after 13 s and Ar (100 mL min-1) was used to carry the mixture to a gas - liquid separator. A second flow of Ar (100 mL min-1), from the opposite direction, transported the AsH3 and H via a quartz tube to a graphite furnace which had been pre-treated with a 20 µg mL-1 Pd solution Interference was found to occur either in the furnace or sample solution. Furnace interferences could be controlled using peak area calibrations or by increasing the quantity of Pd used. Solution interferences could be compensated by increasing acid concentration. or the use of masking agents. The coupling of flow injection hydride generation with in situ concentration. in a graphite furnace is demonstrated to be an effective method for the determination of arsenic in the presence of interferent suppressors. The trapping of arsine on a deposit of reduced Pd is shown to be 100% efficient. The addition of L-cysteine permits full recovery of the As signal in the presence of 100 µg amounts of Ni or Pt. Thiourea is effective at reducing interferences from 100 µg Au, Ni or 10 µg Pd. Increased amounts of Pd or peak area calibration can reduce interferences that occur in the graphite furnace due to other hydride forming elements. A characteristic mass of 10.6 pg and a limit of detection of 36 pg was obtained.
Spectrophotometry Interferences Phase separator Volatile generation Peak area Volatile generation

"Gas-sampling Glow Discharge Coupled To Hydride Generation For The Atomic-spectrometric Determination Of Arsenic"
Spectrochim. Acta B 1993 Volume 48, Issue 10 Pages 1207-1220
J. A. C. Broekaert, R. Pereiro, T. K. Starn and G. M. Hieftje

Abstract: A continuous-flow hydride generation system is described for use in the AES determination of As in solution, using 5% NaBH4, 5% NaOH and 2 M HCl as reagent and He, Ne or Ar as carrier gas. The product gas sampling rate was controlled to maintain a sampling efficiency of >75%. The gas was passed to a silica capillary attached to the cathode of a gas-sampling glow-discharge source, which was operated at constant voltage and pressure. Spatially resolved maps were obtained of the As I 228.8 nm line, the spectral background and the fill-gas lines, all as a function of the discharge pressure. Under optimized conditions the noise amplitude spectra of analytical signals were completely white. The detection limits of As with He (at 6.5 Torr, 650 V and 165 mA), Ne (at 2.5 Torr, 750 V and ~160 mA) and Ar (at 1.5 Torr, 550 V and ~165 mA) were 54, 30 and 20 ng/ml, respectively. The calibration graphs were rectilinear up to 10 µg/ml in the Ar discharge and up to 2.5 µg/ml in Ne and He.
Spectrophotometry Optimization

"The Use Of Nafion Dryer Tubes For Moisture Removal In Flow Injection Chemical-vapor-generation Atomic Absorption Spectrometry"
Spectrochim. Acta B 1995 Volume 50, Issue 4-7 Pages 369-375
Nils G. Sundin and Julian F. Tyson*, Christopher P. Hanna and Susan A. McIntosh

Abstract: A model MD-125 or MD-250 sheathed Nafion drying tube (30.5 cm x 1 or 2.2 mm, respectively; Perma Pure, Toms River, NJ, USA) was connected between the gas-liquid separator of a hydride- or cold vapor-generation unit and the absorption cell in place of the standard PTFE tubing. When 200 ml/min of dry Ar was passed through the sheath of either drying tube, water vapor was removed effectively in the determinations of As, Se and Hg at the cost of only a 3% decrease in peak-height sensitivity for As and Se and a 5% decrease for Hg. The detection limits for Hg with use of the PTFE tubing and the MD-125 and MD-250 tubes were 77, 150 and 20 parts per trillion, respectively.
Spectrophotometry Spectrophotometry PPT Nafion membrane Optimization

"Evaluation Of Electrochemical Hydride Generation For The Determination Of Arsenic And Selenium In Seawater By Graphite-furnace Atomic Absorption With In-situ Concentration"
Spectrochim. Acta B 1996 Volume 51, Issue 11 Pages 1325-1334
W. -W. Ding and R. E. Sturgeon*

Abstract: A continuous-flow electrochemical hydride generation technique coupled with in situ concentration in a graphite furnace has been developed for determination of As and Se in seawater. Lead is used as cathode material for the production of arsine and hydrogen selenide. The efficiency of generation of arsine from As(III) is 86±6%, that from As(V) ranges from 73% to 86%. The efficiency of generation of hydrogen selenide from Se(IV) is 60±5% and from Se(VI) is 30±5%. The hydrides are trapped in an iridium-palladium coated graphite furnace prior to atomization. Absolute detection limits and concentration detection limits of 84 pg (3s(blank)) and 84 pg mL-1 for determination of As using 1 mL sample volume and 75 pg (3s(blank)) and 7.5 pg mL-1 for determination of Se using 10 mL sample volumes are obtained, respectively. The precision of replicate measurement for the analysis of reference materials at the 1.3 µg L-1 level for As(III) (0.8 ng absolute mass level) and at the 0.042 µg L-1 level for Se(IV) (0.42 ng absolute mass level) is better than 4% and 23% (relative standard deviation, RSD), respectively. The RSD values quoted above for Se include errors introduced by the sample preparation procedure.
Environmental Sea Spectrophotometry Reference material Electrochemical product conversion Preconcentration

"Determination Of Heavy Metals By Inductively Coupled Plasma Mass Spectrometry After Online Separation And Preconcentration"
Spectrochim. Acta B 1998 Volume 53, Issue 11 Pages 1527-1539
Valderi L. Dressler, Dirce Pozebon and Adilson J. Curtius*

Abstract: A method for the determination of Cu, As, Se, Cd, In, Hg, Tl, Pb and Bi in waters and in biological materials by inductively coupled plasma mass spectrometry, after an online separation, is described. The matrix separation and analyte pre-concentration is accomplished by retention of the analytes complexed with the ammonium salt of O,O-di-Et dithiophosphoric acid in a HNO3 solution on C18 immobilized on silica in a minicolumn. Methanol, as eluent, is introduced in the conventional pneumatic nebulizer of the instrument. To use the best compromise conditions, concerning the ligand and acid concentrations, the analytes were determined in two sep. groups. The enrichment factors were at 5-61, depending on the analyte. The limits of detection varied from 0.43 ng L-1 for Bi to 33 ng L-1 for Cu. The sample consumption is only 2.3 mL for each group and the sampling frequency is 21 h-1. The accuracy was tested by analyzing five certified reference materials: water, riverine water, urine, bovine muscle and bovine liver. The agreement between obtained and certified concentrations was very good, except for As. The relatively small volume of methanol, used as eluent, minimizes the problems produced by the introduction of organic solvent into the plasma.
River Urine Muscle Liver Mass spectrometry Interferences Method comparison Reference material Preconcentration C18 Silica Ion pair formation

"Hydride-generation System With A Hydrogen Separation Membrane For Low-power Inductively Coupled Plasma Emission Spectrometry"
Anal. Sci. 1990 Volume 6, Issue 2 Pages 195-199
H. TAO, A. MIYAZAKI and K. BANSHO

Abstract: A hydrogen separation membrane module is described consisting of hollow aromatic polyimide fibers. The module, operated at ~90°C, was connected to a continuous-flow hydride generator (diagram given) for removal of H before analysis of the hydrides by ICP-AES with Ar as carrier gas. Detection limits obtained for As, Ge, Hg, Sb and Sn are tabulated. The coefficient of variation were 1% at 50 ng mL-1 of each element. Calibration graphs were rectilinear from the detection limit to 100 µg mL-1. Online pre-concentration with use of the module could not be carried out with He instead of Ar as carrier gas beause He permeated the membrane reducing its flow rate.
Spectrophotometry Detection limit Calibration Preconcentration Membrane

"Gas-phase Chemiluminescence Detection Of Trace Arsenic In Environmental Water"
Anal. Sci. 1990 Volume 6, Issue 3 Pages 425-430
K. FUJIWARA, A. KURAMOCHI and H. TSUBOTA

Abstract: The method involves conversion of As into AsH3, mixing the AsH3 produced with O3 and measurement of the resulting chemiluminescence. The apparatus used is illustrated schematically. For determination of total inorganic As, concentrated HCl was added to the sample to 2M, and for total As, the sample was treated with 15% NaOH - 5% K2S2O8 for 1 h at 80°C to 85°C, 40% KI - concentrated HCl for 20 min at room temp., and then 10% ascorbic acid before analysis. The method allowed determination of As at 1 ng mL-1. The method was applied to rain, seawater and condensed atmospheric moisture. Results were slightly higher than those obtained by flow injection analysis - AAS.
Environmental Rain Sea Chemiluminescence Method comparison Volatile generation Volatile generation

"Determination Of Arsenic And Selenium In River Water By Hydride-generation Inductively Coupled Plasma Mass Spectrometry With High Resolution"
Anal. Sci. 1996 Volume 12, Issue 4 Pages 623-627
H. NARASAKI and J. Y. CAO

Abstract: A hydride-generation flow injection ICP-MS method for the determination of As and Se in river water is presented. For As, 100 mL water was boiled for 5 min with 1 mL concentrated HNO3, the pH was adjusted to 3.5 and the solution was applied to a Chelex 100 chelating resin. For Se, 100 mL water was boiled for 5 min with 2 mL concentrated HCl and the solution was applied to a chelex resin as above after pH adjustment. Both column eluate were diluted with water until the acidity became 0.1 M. Each sample was transferred in turn to the hydride generation system (schematic shown). Variable speed peristaltic pumps were used to mix sample solutions with 0.2% sodium tetrahydroborate(III) solution (both at 1 mL/min) in a Pyrex mixing coil (15 cm x 2 mm i.d.). The hydrides generated were swept continuously into the ICP torch (operating parameters given) and As and Se were detected by the MS operating at a resolution of 10,000 in selected-ion monitoring mode at m/z 75 and 82, respectively. Using standard solutions, the detection limits were 0.03 and 0.06 ng/ml, respectively, for As and Se. Interference levels of foreign ions on the determination of As and Se are listed. Results (tabulated) obtained the elements in NIST reference materials agreed with certified values. The concentration levels of As and Se in Japanese rivers close to industrial production sites were in the range 1.62-3.77 and 0.07-0.48 ng/mL, respectively.
River NIST 1640 Mass spectrometry Interferences Reference material Chelex Resin

"Determination Of Major And Trace-elements For Certified Reference Material Of Riverine Water JAC-0031 And JAC-0032 By ICP-MS"
Anal. Sci. 1997 Volume 13, Issue 2 Pages 177-182
T. SHIMAMURA and M. IWASHITA

Abstract: Element concentrations were determined by ICP-MS for certified reference materials of riverine water JAC 0031 and JAC 0032 which were recently distributed for a collaborative study to determine certified values. Concentrations were determined of nine elements (Mg, Al, Mn, Ni, Cu, Zn, As, Cd and Pb) out of sixteen elements, which were intended to be certified. An additional eleven trace elements (Li, V, Co, Rb, Sr, Mo, Sb, Cs, Pa, W and U) were also determined. The results obtained for the former nine elements generally agreed well with the values from other laboratories and with certified values. The results obtained for the latter eleven elements were consistent with our previous data, which were obtained from our monitoring project for the same river at a nearby sampling point. 39 References
JAC 31 JAC 32 River Mass spectrometry Reference material Method comparison

"Simultaneous Determination Of Hydride And Non-hydride Forming Elements By Inductively Coupled Plasma Atomic-emission Spectrometry"
Anal. Proc. 1992 Volume 29, Issue 10 Pages 438-439
Zhang Li, Susan McIntosh and Walter Slavin

Abstract: Arsenic, Se, Sb, Bi, Cd, Cr, Cu, Fe, Mn, Ni and Pb were determined in the NIST environmental standard reference materials steel, coal fly ash, urban particulated and 1643b water by ICP-AES. A Perkin-Elmer FIAS-2000 flow injection system was used for hydride generation (experimental conditions tabulated). The sample solution was split into two streams, one being pumped directly to the nebulizer, the other mixed with HCl and NaBH4 solution in the mixing tubes of the chemifold. After separation, the hydride was swept into the spray chamber through a slightly modified cross-flow nebulizer cap. The hydride was then carried into the plasma together with sample aerosol. Recoveries of 20 µg L-1 of As, Sb and Se and 50 µg L-1 of non-hydride forming elements in river- and seawater standards were >80%.
NIST 1643 NIST 1633 NIST 1648 Particulates Alloy Environmental Coal Fly ash River Sea Spectrophotometry Spectrophotometry Reference material FIAS-200 Nebulizer Volatile generation Volatile generation

"Applications Of Trace Metals Analysis At ICI Specialties Research Centre"
Anal. Proc. 1993 Volume 30, Issue 11 Pages 440-441
Sharon C. Stephen

Abstract: The determination is discussed of Cr(III) and Cr(VI) in dyes by LC on a column (25 cm x 4.6 mm) of Hypersil ODS with a mobile phase (2 ml/min) of tetrabutylammonium sulfate of pH 6.75/acetonitrile (4:1) with detection at 380 nm, by AAS at 357.9 nm and by dialysis followed by AAS or ICP-AES. Trace impurities in Cu were determined using ICP-MS with In as internal standard and FIA in a dilute HNO3 carrier stream with solvent extraction. Results were compared to certified values of reference materials. Results are tabulated for the determination of Ag, As, Bi, Fe, Pb and Sb.
Metal Organic compound Mass spectrometry Spectrophotometry Spectrophotometry Sample preparation Speciation Reference material Internal standard Dialysis

"Tandem Online Separations: An Alternative Sample Presentation In Atomic Spectrometry For Ultra-trace Analysis"
Acta Chim. Hung. 1991 Volume 128, Issue 4-5 Pages 551-558
Sanz Medel, A.;Menendez Garcia, A.;Fernandez, M.L.;Sanchez Uria, J.E.

Abstract: The coupling of continuous-separation - pre-concentration. devices with atomic spectrometers for ultra-trace elementary analysis is discussed. Simple systems are first outlined, including solid - liquid and liquid - liquid online flow injection extraction coupled with AAS or ICP-AES for Al determination in biological fluids, and continuous gas - liquid separation coupled with ICP-AES for As determination in steel and as an introduction device for S2- determination in a microwave plasma. Examples are then given of tandem configurations in which two different continuous separation units are combined in a single online configuration. A tandem online device based on continuous extraction combined with hydride generation and coupled with ICP-AES for direct As, Sb and I- determinations is described, as well as a continuous liquid - liquid extraction device coupled with ICP-AES or AAS for indirect I- determination. Results show that many sensitivity and selectivity limitations of ultra-trace analysis can be overcome by the use of tandem online separation techniques.
Alloy Biological fluid Spectrophotometry Spectrophotometry Sample preparation Extraction Preconcentration Ultratrace

"Arsenic, Selenium And Mercury In Mineral And Curative Waters"
Brauwelt 1990 Volume 130, Issue 37 Pages 1588-1591
Meier, B.;Dietschmann, U.;Gigl, C.;Seberich, M.;Postel, W.

Abstract: The three elements were determined by AAS following hydride reduction in a flow injection system. For the determination of As, sample was mixed with HCl and KI solution (5% KI and 5% ascorbic acid), injected into a carrier of 2% HCl and reduced with NaBH4 in NaOH. The same carrier and reagent were used for the determination of Se, reduced by heating (90°C, 20 min) the sample with HCl (12 min) and diluting with water. Organic forms of Hg were converted to ionic forms by shaking the sample with HNO3, KMnO4 and water. The sample was injected into a carrier of KNO3 and reduced with NaBH4 in NaOH. The metallic Hg formed was amalgamated with Au or Pt gauze and was released into a stream of Ar by heating (600°C) for AAS analysis. The detection limits were 0.3, 0.6 and 0.1 µg L-1 for As, Se and Hg, respectively. The coefficient of variation (n = 20) were 2.9% (As and Se) and 5.2% (Hg). Results are discussed for the analysis of 44 mineral waters and six curative waters.
Mineral Curative Spectrophotometry Spectrophotometry Dilution Volatile generation Amalgamation Volatile generation

"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.
Environmental Chemiluminescence Ion exchange Reference material Column Resin

"Determination Of Arsenic And Selenium In Coal And Fly Ash By Continuous-flow Hydride-generation ICP-AES"
Bunseki Kagaku 1987 Volume 36, Issue 9 Pages T95-T99
Etoh, M.

Abstract: Coal was digested with HNO4 and HClO3 and fly ash was digested with HNO3 and H2SO4. The As and Se were separated from co-existing elements (except for Sb, Sn and Ge) by distillation with HBr and Br. Arsenic and Se were determined by continuous-flow hydride-generation ICP-AES. Recoveries were 98 to 104%, and coefficient of variation were 2.4 to 3.5 and 2.7 to 4.5%, respectively, for As and Se. Tin, Sb and Ge did not interfere at concentration. present in the samples used.
Coal Coal Fly ash Sample preparation Spectrophotometry Interferences

"Determination Of Arsenic And Selenium By Hydride Generation Atomic Absorption Spectrometry (flow Injection Or Continuous-flow) Method Combined With A Hydride Collecting Trap"
Can. J. Anal. Sci. Spectrosc. 1995 Volume 40, Issue 5 Pages 117-124
Siska, R.;Borszeki, J.;Gegus, E.

Abstract: A hydride collecting cold trap hydride generation AAS method has been developed using a flow injection (FI) or a continuous-flow (CF) system, applicable to the high sensitivity determination of arsenic and selenium, characterized by a detection limit of 10^-20 pg/mL. The best relative detection limits and sensitivity for this system could be achieved using the CF operation mode. Accuracy and reproducibility of the method were investigated by the analysis of dilute solutions produced by decomposition of international CRM samples of various types. The results of the determinations agree well with the certified values. Reproducibility of the measurements is good considering especially the extreme low initial concentrations. The remarkable feature of the method is the relatively low blank value which is partly due to the use of high purity acids and reagents, and partly to the very low risk of contamination when the work is done in a closed system. Further on, several water samples were investigated by this method, the arsenic and selenium content of which could not be determined previously. Also numerous food samples having low content of As and Se were analyzed. (12 references)
Food Water Spectrophotometry Cold trap Optimization Reference material Volatile generation Volatile generation

"Design Of A Combined Cell For The Electrochemical Generation Of Volatile Compounds In Atomic Absorption Spectrometric Method"
Chem. Listy 1998 Volume 92, Issue 8 Pages 676-679
J. Sima and P. Rychlovsky

Abstract: The construction, testing, and evaluation of the application, combining an electrochemical generator of hydrides and separator of gaseous and liquid phases into one combined cell operating both in CFA and FIA regimes, are described. Arsenic was chosen for testing as a commonly determined hydride-forming element often described in literature.
Spectrophotometry Volatile generation Electrochemical product generation Phase separator

"Trace Elements Determined Along Single Strands Of Hair By Inductively Coupled Plasma Mass Spectrometry"
Clin. Chem. 1993 Volume 39, Issue 8 Pages 1650-1655
Jun Yoshinaga, Yasuyuki Shibata, and Masatoshi Morita

Abstract: Flow injection inductively coupled plasma mass spectrometry has been evaluated for determining the distribution profile of trace elements along a single strand of hair. Hair was cut into several mm long sections from follicle to the distal end. Each section was solubilized in a capped 1.5 mL polypropylene tube with small volume of nitric acid (typically 50 µL) at room temperature. After dilution an aliquot (50 µL) was introduced into the mass spectrometer by flow injection. The limit of determination was typically 5-50 pg with 5-10% precision (CV), depending on the element examined; this corresponds to sub-microgram/g concentrations of these elements in hair segments. Recent exposure and intake history of individuals to thallium or mercury could be reconstructed by this system. Sections of hair strand (several mm in length) were incubated overnight at room temperature with 50 µL of HNO3. After addition of water, a 50 µL portion was subjected to ICP-MS by flow injection (six-way valve and PTFE tubing, 0.5 mm i.d.). The limits of determination were 0.1, 1.0, 0.1, 0.05, 0.05, 0.1, 0.01 and 0.05 µg/l of Cu, Zn, As, Cd, Sb, Hg, Tl and Pb, respectively. Calibration graphs were linear for 1.0 ppb of Pb, Cd or As. The RSD (n = 4-6) were 5-10%.
Hair Spectrophotometry Mass spectrometry Clinical analysis

"Arsenic In Ground Water In Seven Districts Of West Bengal, India The Biggest Arsenic Calamity In The World"
Curr. Sci. 1996 Volume 70, Issue 11 Pages 976-986
Badal K. Mandal, Tarit Roy Chowdhury, Gautam Samanta, Gautam K. Basu, Partha P. Chowdhury, Chitta R. Chanda, Dilip Lodh, Nirmal K. Karan, Ratan K. Dhar, Dipak K. Tamili, Dipankar Das, K. C. Saha and D. Chakraborti

Abstract: Arsenic has been found in groundwater in seven districts of West Bengal covering an area 37,493 km(2) having about 34 million population. Our survey indicates that 560 villages are arsenic-affected and more than a million people are drinking arsenic contaminated water and more than 200,000 people are suffering from arsenic-related diseases. About 20,000 tubewell waters were analyzed for arsenic Around 45% of these tubewells have arsenic content above 0.05 mg/l. The average concentration of arsenic in contaminated water is about 0.20 mg/l; the maximum concentration of arsenic is found to be 3.7 mg/l. Most of the tubewells water contain arsenic in the form of arsenite and arsenate. People having arsenical skin manifestations and drinking contaminated water have high arsenic in hair, nail, urine and skin scales. Flow injection hydride generation-atomic absorption spectrometry has been used for arsenic analysis in various samples. Many people have arsenical skin lesions as: melanosis, leucomelanosis, keratosis, hyperkeratosis, dorsum, non-petting oedema, gangrene, skin cancer. More informations are coming where the arsenic patients are suffering from cancers of bladder, lung, etc. The source of arsenic is geological. The reason why arsenic is leached out from the source is not yet clear but owing to heavy groundwater withdrawal the geochemical reaction in underground may be the reason. The vast surface and rain water resource, which West Bengal has should be used properly to combat the situation. Proper watershed management is required urgently.
Ground Spectrophotometry Volatile generation Volatile generation

"Determination Of Trace Amounts Of Arsenic By Flow Injection Analysis - Hydride Generation - Inductively Coupled Plasma Atomic-emission Spectroscopy"
Fenxi Ceshi Tongbao 1990 Volume 9, Issue 1 Pages 9-14
Chen Hao;Jiang Zucheng;Kong Linying;Zen Yun'e

Abstract: A double capillary nebulizer was used to generate the hydride of the analyte. Factors affecting line intensity in the flow injection system were investigated. The effects of several inorganic acids, their acidity and inter-element interference effects were examined. Under optimum conditions the detection limit of As was 5.2 mg mL-1; the coefficient of variation was 1.48% for 2 µg mL-1 (n = 10). Recoveries of Al from NaCl and AlCl3.xH2O were >95%.
Spectrophotometry Nebulizer Interferences Detection limit Optimization

"Semi-automated Flow Injection Analysis System For The Determination Of Trace Arsenic By Hydride Generation Atomic Absorption Spectrometry"
Fenxi Huaxue 1988 Volume 16, Issue 10 Pages 912-915
Wang, X.;Fang, Z.L.

Abstract: A flow injection analysis system with automated sample introduction was used to determine trace As in soil and plants by hydride-generation AAS. The sampling frequency was 220 h-1 for a sample volume of 0.4 mL. The detection limit was 0.1 µg L-1 and the coefficient of variation was 1.5% (n = 13) for 6 µg L-1 of As. Interference from foreign ions was less than for the manual method although serious interference from Fe(III) was observed; this was overcome by treating the sample with KI initially. Selenium also interfered at >20 µg l-1, but was masked by 10 mg L-1 of Cu in the acidic carrier solution.
Plant Environmental Spectrophotometry Interferences

"Determination Of Arsenic, Antimony And Bismuth By Inductively Coupled Plasma Atomic-emission Spectrometry With Flow Injection Analysis And Hydride Generation"
Fenxi Huaxue 1991 Volume 19, Issue 11 Pages 1285-1287
Gao, H.;Li, K.

Abstract: A 0.175-g ore or rock sample was wetted with a little water and then dissolved in 9 mL of HCl plus 3 mL of HNO3 and 1 mL of H2SO4 (1:1); after evaporation to fumes and cooling, 2.5 mL of HCl, 5 mL of 10% KI - 5% ascorbic acid - 5% thiourea solution and water were added to 25 mL. The solution was then carried at a flow-rate of 11 mL min-1 to react with 1% KBH4 solution (containing 0.2% of NaOH) at 5.5 mL min-1 in the flow injection system (diagram pesented), and the generated hydrides were carried by Ar (0.6 l min-1) for separation by a gas separator before passing to a direct-reading spectrometer for ICP-AES determination of As, Sb and Bi with measurement at 193.76, 217.5 and 306.7 nm, respectively. By the standard-additions method, recoveries were 94 to 107%. Determination ranges for As, Sb and Bi were up to 1000, 300 and 300 µg g-1, respectively, and their corresponding detection limits were 0.2, 0.2 and 0.1 µg g-1. Masking agents could be used to increase tolerance levels of the co-existing ions; background interferences in the gas phase could be corrected for.
Geological Geological Spectrophotometry Interferences Standard additions calibration

"Determination Of Arsenic, Antimony And Bismuth By Flow Injection Analysis Hydride-generation Graphite-furnace Atomic Absorption Spectrometry"
Fenxi Huaxue 1992 Volume 20, Issue 6 Pages 670-673
Wang, Z.;Wang, Y.

Abstract: A method was developed for the determination of As, Sb and Bi by the cited technique and applied to the analysis of soil. Sample solution (prep. described) was injected into a carrier stream (5.6 to 6.4 mL min-1) of 1 M HCl - 1 M HNO3 - 2 M H2SO4 which merged with a stream of NaBH4 in 0.2% NaOH. The mixture was passed to a gas - liquid separator where the generated hydrides were carried to the graphite-furnace by a stream of Ar (250 mL min-1) for AAS determination of As, Sb and Bi with measurement at 193.7, 217.6 and 223 nm, respectively. Recoveries were 94 to 99% with coefficient of variation of 0.4 to 0.9%. Detection limits for As, Sb and Bi were 6.29, 9.21 and 3.77 pg, respectively. The combined method of flow injection analysis with hydride generation and graphite furnace-at. absorption spectrometry (GFAAS) is studied. This method has high sensitivity, low detection limit, high precision, and high selectivity. As, Sb and Bi were determined., the detection limit was all below 10 pg. The interference mechanism of Cu has also been studied with x-ray diffraction method.
Environmental Spectrophotometry Phase separator Interferences Volatile generation Volatile generation

"Determination Of Arsenic By Flow Injection Analysis With Hydride-generation Spectrophotometry"
Fenxi Huaxue 1992 Volume 20, Issue 7 Pages 810-812
Liu, G.Q.;Wang, C.X.;Xie, B.;Wu, W.H.

Abstract: A flow injection online hydride generation spectrophotometric system is described for the cited determination (schematic given). The absorption solution used was HNO3 - AgNO3 - PVC - ethanol; there was no need for any carrier solution The system was applied to the analysis of soil. Sample (0.2 g) was wetted with water, treated with 10 mL of concentrated HNO3 and heated to fumeless. The cooled residual solution (~1 ml) was mixed with 10 mL of 0.5 M HCl and a little ascorbic acid, the mixture was heated for 2 to 3 min and cooled to room temperature The solution was diluted with HCl - KCl buffer solution (pH 1.1) and analyzed by the proposed system. Sample throughput was 30 h-1.
Environmental Sample preparation Spectrophotometry Buffer Volatile generation Volatile generation

"Determination Of Trace Arsenic, Selenium, Molybdenum, Sulfur And Chromium With Online Flow Injection Anion-exchange Preconcentration Inductively Coupled Plasma Atomic-emission Spectrometry"
Fenxi Huaxue 1993 Volume 21, Issue 3 Pages 328-330
Liu, E.;Chen, W.J.;Zhao, C.Y.

Abstract: A system for online flow injection anion-exchange pre-concentration. ICP-AES (diagram given) for determination of As, Se, Mo, S and Cr is described. Sample solution was passed through two parallel columns (8 cm x 2 mm) packed with D296 anion-exchange resin (40 mesh) at a flow rate of 1.23 mL min-1 for pre-concentration.; elution was effected with 0.5 M NH4Cl and 3 M NH3 (1.23 mL min-1) and exposure time was 40 s. The detection limits were 13, 25.2, 2.04, 6.19 and 3.64 ng mL-1 for As, Se, Mo, S and Cr, respectively. The method was used for the analysis of geological, hair and bovine liver standards. Results agreed with the certified values.
Geological Hair Cell Spectrophotometry Sample preparation Ion pair extraction Reference material Preconcentration

"Determination Of Trace Arsenic In Copper Alloy By Online Flow Injection - Hydride-generation Inductively Coupled Plasma Atomic-emission Spectrometry"
Fenxi Huaxue 1994 Volume 22, Issue 8 Pages 816-818
Wang, H.N.;Chen, Y.

Abstract: Sample (1 g) was decomposed with 6 mL HNO3 and the pH was adjusted to 1 and diluted to 100 mL with water. The solution was injected into the analysis system and transferred by a stream of water at 1.6 ml/min to a column (5 cm x 5 mm i.d.) of cation-exchange resin and eluted with 2.2 M HCl at 4.4 ml/min; the eluate was mixed with 2.2 M HCl at 1.6 ml/min treated with 1% NaBH4 at 1 ml/min. The generated hydride was directly determined by ICP with measurement at 228.8 nm. The detection limit was 0.9 µg/g. Interference from up to 10 mg/ml of Cu(II) could be eliminated. Recovery was 102-104%. Sampling frequency was 25 runs/h.
Alloy Ion exchange Spectrophotometry Volatile generation Interferences Resin Volatile generation

"Determination Of Trace Arsenic In Water By Luminol/hydrogen Peroxide/chromium(III) Chemiluminescence After Sulfhydryl Cotton Enrichment And Separation"
Fenxi Huaxue 1996 Volume 24, Issue 11 Pages 1320-1322
Jia, S.H.;Lu, J.Y.;Zhang, H.Q.

Abstract: Water (100 ml) was adjusted to 1 M HCl, treated with 2 mL reducing reagent containing 200 g/l KI and 20 g/l thiourea, heated at 80°C for As was eluted with hot concentrated HCl. The eluate was heated with 5 mL 50 mM K2Cr2O7 and 1 mL 1 M H2SO4 for 10 min then 1 mL 0.1 M EDTA was added, the pH was adjusted to 2.5, and the solution was diluted with water. A portion was injected into a FIA system to react with streams of 0.25 µM-luminol and 40 mM H2O2 and the generated chemiluminescence was measured. The calibration graph was linear from 0.1 µg/l to 0.1 mg/l As(III) and the detection limit was 34 ng/l. There was no interference. The method was used in the direct analysis of tap water and river water, with recoveries of 95-103% and RSD of 4.2-10.6%.
River Water Chemiluminescence Sulfhydryl cotton Interferences Heated reaction Preconcentration

"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.
Environmental Environmental Spectrophotometry

"Determination Of Trace Arsenic With L-cysteine As Prereductant Using Flow Injection-hydride Generation-atomic Absorption Spectrometry"
Fenxi Huaxue 1998 Volume 26, Issue 8 Pages 1037-1037
Xu, G.M.;Lu, X.H.;Yin, X.F.

Abstract: The title method is characterized by having low detection limit (0.05 µm/L), good precision (1.8% RSD), and fast operation (65 samples/h). The method has applied to the anal. of steel and sea water.
Alloy Sea Spectrophotometry Volatile generation

"Study On Application Of Flow Injection Analysis - Hydride-generation Graphite-furnace Atomic Absorption Spectrometry. 1. The Experimental Device And Its Analytical Property"
Fenxi Shiyanshi 1993 Volume 12, Issue 1 Pages 87-90
Ma, Y.P.

Abstract: A semi-automatic sampling device for introduction of hydride into the graphite furnace and a flow injection hydride generator were developed. Detection limits were optimized and interferences were eliminated in the liquid and gas phases by the decomposition and deposition of the hydride on the graphite tube wall at low temperature followed by atomization at high temperature The device was used to determine Hg, As, Se, Sb, Sn and Bi without any modification to the graphite furnace. Results were compared with those obtained by conventional hydride-generation AAS and graphite-furnace AAS.
Spectrophotometry Volatile generation Method comparison Optimization Interferences Phase separator Volatile generation

"Microamount Flame Atomic Absorption Technique And Its Application"
Fenxi Shiyanshi 1993 Volume 12, Issue 1 Pages 77-81
Gao, Y.Q.;Wu, R.;Chi, K.;Wu, H.Z.

Abstract: A theoretical model of the cited technique was developed (equations given) in order to improve sensitivity. Three examples are discussed: (i) trace Au in ores was determined using a combination of a high efficiency nebulizer (HEN), a high performance hollow cathode lamp (HPHCL), a slotted quartz tube (SQT) and FIA with a detection limit of 0.2 ng mL-1 of Au; (ii) trace Pb in water was determined using a combination of HEN, HPHCL and SQT with a detection limit of 1.6 ng mL-1 of Pb; and (iii) trace As in water was determined using a combination of HPHCL, SQT and a HG-3 hydride generator with a detection limit of 3 ng mL-1 of As.
Water Spectrophotometry Spectrophotometry Theory

"Determination Of Trace Arsenic By Flow Injection Hydride-generation Atomic Absorption Spectrometry With Online Reduction"
Fenxi Shiyanshi 1994 Volume 13, Issue 2 Pages 20-22
Xu, S.K.;Fang, Z.L.

Abstract: Water was mixed with concentrated HCl (2:1), injected and transferred at 4.4 ml/min to mix with a stream of KI in 1 M HCl (300 g/l) at 4.4 ml/min in a knotted reactor (1 m long, 0.5 cm i.d.). The sample was stored in a 400 µL sampling loop for 40 s and reduced by injection into a stream of NaBH4 in 0.125 M NaCH at 5 ml/min in the presence of a carrier stream of 1 M HCl at 8 ml/min in a mixer and then a reaction tube (both 20 cm/mg, 0.7 mm i.d.). The generated hydride was separated in a gas-liquid separator and transferred with Ar at 120 ml/min for AAS analysis. The detection limit was 0.1 µg/l of As. For 10 µg/l of As, recoveries ranged from 104-105% with RSD of 1.4-1.5%. Soil was similarly analyzed. The sampling rate was 55 samples/h.
Environmental Environmental Spectrophotometry Knotted reactor Volatile generation Phase separator Redox Volatile generation

"Simultaneous Determination Of Trace Arsenic, Antimony And Bismuth In Electrolytic Copper Sample By Flow Injection Hydride Generation Coupled With Inductively Coupled Plasma Atomic Emission Spectrometry"
Fenxi Shiyanshi 1998 Volume 17, Issue 1 Pages 57-59
Yu, X.;Chen, J.;Wang, S.;Liao, Z.;Jiang, Z.

Abstract: The technique of flow injection hydride generation coupled with ICP-AES and its application on determining trace As, Sb and Bi in electrolytic Cu was studied. An effective method was established, the relative standard deviation for determination of As, Sb, Bi was 2.3, 1.8, 2.8% (n = 11), and the detection limit was 0.3, 0.3, 1.15 µg/g respectively.
Metal Spectrophotometry Simultaneous analysis Volatile generation

"Elimination Of Interferences In ICP-AES By Flow Injection Gradient Technique-generalized Standard Addition Method"
Gaodeng Xuexiao Huaxue Xuebao 1989 Volume 10, Issue 12 Pages 1185-1188
Luo Jianbo, Zhang Zhanxia, Qian Haowen, Cai Mingxiang

Abstract: A method based on a flow injection gradient technique (FIGT) and generalized standard addition method (GSAM) is developed for the elimination of matrix and/or spectral interferences in inductively coupled plasma atomic emission spectrometry (ICP-AES). Only one standard for an analyte is used to obtain the signals required for the evaluation in the GSAM. Operating parameters, including the carrier flow rates and residence times, are discussed in detail. To assess the proposed method, two synthetic samples, two types of Cu alloys and steel were analyzed for Zn, Mn, and As respectively. The relative standard deviations are 0.5-1.9%.
Alloy Alloy Spectrophotometry Gradient technique Interferences Standard additions calibration

"Automated Determination Of Arsenic, Antimony, Selenium And Mercury In Water"
GIT Fachz. Lab. 1997 Volume 41, Issue 5 Pages 475-476
Sinemus, H.W.;Stabel, H.H.;Kleiner, J.;Radziuk, B.

Abstract: The hydride-forming elements and Hg were concentrated by pumping the sample and the reducing solution (NaBH4 or SnCl2, respectively) into a manifold, entraining the hydride or Hg vapor in Ar and introducing the gas stream into a pyrolytic graphite tube equipped with an Ir-coated platform for AAS determination. The operating program of the automated system is shown. For the determination of As, Sb and Se, samples were collected in fluorinated ethylene/propene or polyethylene terephthalate co-polyester vessels and stabilized with 0.2% HCl, and were treated with 37% HCl, KI, ascorbic acid, hydroxylammonium chloride and sulfamic acid to reduce As and Sb in higher oxidation states or with 37% HCl, sulfamic acid and ammonium sulfate to reduce Se(VI). Samples to be analyzed for Hg were collected in hard glass vessels and stabilized with HNO3/potassium dichromate and H2SO4. Organic Hg compounds were decomposed ultrasonically in the presence of KMnO4 and ammonium persulfate. Hydroxylammonium chloride was added to reduce permanganate before the analysis. Very small amounts of Hg were pre-concentrated on Au/Pt gauze. Characteristic masses for As, Sb and Se were 24, 38 and 45 pg, respectively. Down to 3 ng/l of Hg could be detected.
Water Sample preparation Spectrophotometry Preconcentration Volatile generation Automation Volatile generation

"Determination Of Trace Arsenic In Geological Samples By Flow Injection Hydride Generation-vapor Storage And Pulsed Sampling Atomic Fluorescence Spectrometry"
Guangpu Shiyanshi 1998 Volume 15, Issue 5 Pages 28-31
ZHOU Junming, CHENG Xianghong

Abstract: A method for the determination of trace As in geological samples by flow injection hydride generation-vapor storage and pulsed sampling atomic fluorescence spectrometry was developed. The performances of two kinds of vapor storage system were compared. The analytical sensitivity of As has increased by 1760%. The detection limit is 0.32 ng/mL and relative standard deviation 2.1%. Analytical results of geological standard reference materials are satisfactory.
Geological Fluorescence Reference material

"Comparison Of The Analytical Performances Of Membrane And U-tube Phase Separators For Flow Injection Hydride-generation Atomic-fluorescence Spectrophotometry"
Guangpuxue Yu Guangpu Fenxi 1995 Volume 15, Issue 1 Pages 69-74
Lin, S.L.;Lu, C.G.;Tong, Z.Y.;Chiu, H.

Abstract: Analytical performances of the two set-ups were compared in terms of sensitivity, detection limit, precision, suppression of interferences and simplicity of operation with As, Sb, Bi, Se and Te as the analytes. Both membrane and U-tube phase separators performed similarly and could be used in the assay of geochemical samples. However, the membrane separator had a shorter lifespan and required frequent renewal.
Fluorescence Membrane Phase separator Interferences Volatile generation Volatile generation

"Online Preconcentration And Determination Of Trace Arsenic In Water By Flow Injection Flame Atomic Absorption Spectrophotometry"
Guangpuxue Yu Guangpu Fenxi 1995 Volume 15, Issue 4 Pages 91-94
Sai, Y.;Yang, W.B.;Zhang, X.Y.

Abstract: Sample of natural water (pH 6) was applied to a column (10 x 3.5 mm) packed with activated Al2O3(140-200 mesh) at a flow rate of 16 ml/min, pre-concentrated for 1-2 min and eluted with 8 M HCl at 8 ml/min. Portions of eluate was analyzed by the cited method under the following conditions, wavelength 193.7 nm, lamp current 6 mA, slit width 0.95 nm, burner height 5 mm, air flow 10 l/min and acetylene flow 2 l/min. The calibration graph was linear from 0.03-2 µg/ml of As. RSD (n = 9) were 8 and 4%, respectively, for 0.87 and 0.03 µg/ml of As.
Environmental Spectrophotometry Preconcentration Alumina Column

"Online Cold-trap Hydride Collection Flow Injection Determination Of Arsenic And Antimony In Seawater"
Haiyang Xuebao 1989 Volume 9, Issue 2 Pages 255-261
Lu, Xiankun; Li, Jing; Chen, Shuzhu; Dai, Guosheng

Abstract: An automatic flow analysis system with on-line liquid nitrogen trap, hydride generation and flame-less atomic absorption spectrophotometry was presented for the determination of inorganic arsenic and antimony in seawater. The experimental conditions such as acidity of reduction reaction, the amount of sodium borohydride, the flow rate of carry gas (high purity of nitrogen) were tested and selected optimally. The limit detection of the method presented was 0.15 µg/L for arsenic and 0.24 µg/L for antimony. During the determination of seawater samples with levels microgram arsenic and antimony per liter the variation coefficient would be ±4% for arsenic and ±10% for antimony. The volume needed for one measurement was 9 mL for arsenic and 12 mL for antimony. The frequency of sample determination reached 20 times per hour for arsenic and 15 times per hour for antimony.
Sea Spectrophotometry Cold trap Volatile generation

"Study On The Determination Of Arsenic In Wastewater By Using Single Valve FIA Combined With Hydride Generation Spectrophotometry"
Huanjing Kexue 1994 Volume 15, Issue 5 Pages 71-72
Liu Guoquan, Wang Chunxu, He Yuaping

Abstract: A single valve FIA (Flow Injection Analysis) system with hydride generation spectrophotometric detection was designed for the determination of the trace arsenic in wastewater. This FIA system had no need for any carrying gas. The new hydride generator and the absorbing device made by the authors were used in the FIA system. The KBH-4 solution and the mixed silver nitrate-polyvinyl alcohol-ethanol solution were used for the generation and absorption, respectively, of arsenic hydride. The experimental results show that this method was very good for the determination of trace arsenic in wastewater. The FIA system had main advantages, including simple equipment, easy operation, high sensitivity, rapid determination (30 samples/h), good reproducibility (RSD = 3.04%) and low detection limit (1.82 x 10^-9 g/ml).
Waste Spectrophotometry Valve Phase separator Sensitivity

"Determination Of Trace Arsenic In Water By Flow Injection Hydride Generation Atomic Absorption Spectrometry"
Huanjing Wuran Yu Fangzhi 1998 Volume 20, Issue 4 Pages 35-37
Xu Guangming A.Ali Lu Xiaohua Yan Xuefeng

Abstract: A method for determination of trace As in water by flow injection hydride generation atomic absorption spectrometry was presented, L-cysteine was used as pre-reductive agent to reduce As(V) to As(III). The linear range was 0-15.0 µg L-1, linearly dependent coefficient γ 0.9999°C, detection limit 0.05 µg L-1, relative standard deviation 1.8%, and recovery of As 95-104%.
Water Spectrophotometry

"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)
Environmental Spectrophotometry Spectrophotometry Volatile generation Optimization

"Determination And Speciation Of Arsenic In Human Urine By Ion-exchange Chromatography - Flow Injection Analysis With Hydride Generation - Atomic Absorption Spectroscopy"
J. AOAC Int. 1994 Volume 77, Issue 2 Pages 441-445
Jimenez De Blas, O.;Vicente Gonzalez, S.;Seisdedos Rodriguez, R.;Hernandez Mendez, J.

Abstract: For the determination of total As in urine, the organic matter was oxidized by a mineralization procedure (Minoia et al., Med. Lavoro, 1978, 69, 681) before determination by FIA - hydride-generation AAS using a standard-additions method. Separation of metabolic forms of As was performed by cation-exchange on a column (20 m x 1 cm i.d.) of AG50W-X80 (H+ form; 100-200 mesh) washed with 0.5 M HCl. The urine sample was acidified with concentrated HCl before elution by gravity (~3 ml/min). The method was based on that previously described by Tam et al. (cf. Bull. Environ. Contam. Toxicol., 1979, 21, 371) and the fractions collected were analyzed for As species by FIA - hydride-generation AAS. The instrument used was a Model AA-1475 (Varian Analytical Instruments, Sunnyvale, CA, USA) with an air-acetylene flame and an hollow cathode lamp at 9 mA; As was detected at 193.7 nm (full operating conditions are listed). The detection limits were 2 ppb for each As form and 3 ppb for total As after mineralization of wine. Recoveries were 93, 91 and 85% for 10 ppb of inorganic As, 20 ppb of monomethylarsonic acid and 40 ppb of dimethylarsinic acid, respectively. RSD (n = 10) were 3.2-4.6%. The method can be used for studying exposure to As.
Urine Wine Spectrophotometry Speciation Standard additions calibration

"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).
Environmental Mass spectrometry Sample preparation Simultaneous analysis Volatile generation Volatile generation

"Determination Of Arsenic And Selenium In Whole Fish By Continuous-flow Hydride-generation Atomic Absorption Spectrophotometry"
J. AOAC Int. 1989 Volume 72, Issue 3 Pages 484-486
Brumbaugh WG, Walther MJ

Abstract: Freeze-dried homogenized fish tissue (~0.5 g) and 2 to 3 mL of methanol were mixed with 5 drops of anti-foaming agent, 10 mL of 40% Mg(NO3)2.6H2O and 10 mL of HNO3, and the mixture was heated under reflux at 70°C to 80°C overnight. The temperature was increased to 200°C, the mixture was evaporated to dryness and the residue was placed in a cold muffle furnace. The temperature was increased to 500°C over 3 to 4 h (held for 2 to 4 h), the mixture was cooled, 20 mL of 50% HCl was added and the solution was boiled for 1 h on a hot plate. After cooling, the volume was adjusted to 20 mL with 50% HCl and As and Se in the solution were determined by hydride-generation AAS at 193.7 and 196.0 nm, respectively, with 0.6% NaBH4 - 0.5% NaOH and 1% NaBH4 - 0.5% NaOH as reductants for Se and As, respectively. Detection limits were ~0.06 and ~0.04 µg g-1 for As and Se, respectively, and the average coefficient of variation for both elements was 4%.
Fish Tissue Sample preparation Spectrophotometry Volatile generation Volatile generation

"Continuous-flow Vapor Generation For Inductively Coupled Argon Plasma Spectrometric Analysis. 2. Arsenic"
J. AOAC Int. 1991 Volume 74, Issue 3 Pages 516-521
Tracy ML, Littlefield ES, Moller G.

Abstract: Biological tissue, blood or water, is wet ashed in a 10 mL test tube on a programmed heating block with HNO3, H2SO4 and HClO4 at up to 310°C (details given). The cooled digest is treated with HCl and KI and the As present is reduced by NaBH4 to arsine in a simplified continuous-flow manifold. A standard pneumatic nebulizer effects the gas - liquid separation of AsH3 which is quantified by ICP-AES at 193.756 nm. The detection limit was 0.4 to 0.6 µg L-1 of As. Mean coefficient of variation were 1.2% for analysis of water samples (n = 27) and 2% for analysis of liver samples (n = 12). Recoveries ranged from 99 to 104% for tap water, bovine liver and rice flour.
Water Liver Rice Flour Blood Spectrophotometry Heated reaction Nebulizer Phase separator Reference material Volatile generation

"Design Considerations For An Automated Hydride-evolution System Based On Continuous-flow Principles"
J. Autom. Methods Manag. Chem. 1980 Volume 2, Issue 3 Pages 134-138
A. L. DENNIS and D. G. PORTER

Abstract: Environmental concentrations of elements such as arsenic, selenium and, to a lesser extent, antimony, are of considerable interest because of their potential toxicity. The Laboratory of the Government Chemist is called on to monitor levels of arsenic and selenium in water and very sensitive methods for their measurement are therefore required. Investigations have shown that adequate sensitivity can be obtained by using a modification of an automated hydride evolution procedure developed by Goulden and Brooksbank [1]. This procedure utilises continuous flow techniques to generate the hydrides which are then fed to an on-line atomic absorption spectrometer. One of the inherent advantages of automation, compared with a manual approach, is that more precise control can be maintained in a routine environment. A very rigid control of both gas and liquid flows is essential for the successful operation of a continuous flow hydride evolution system, and this paper will describe the developm/ent of an automated system that has worked routinely in the authors' laboratory for several years, and which forms the basis of a commercially available system. The construction is modular and where possible readily available commercial-components have been used. Particular attention has been paid to the safe and consistent pumping of corrosive materials and of slurries. The performance and potential for further development of the system will be discussed.
Environmental Spectrophotometry Apparatus Volatile generation Volatile generation

"Ultratrace-level Detection Of Arsenic And Selenium Using A Commercially Available Hydride Generator With Atomic Absorption Detection"
J. Autom. Methods Manag. Chem. 1983 Volume 5, Issue 4 Pages 193-196
R. W. WARD and P. B. STOCKWELL

Abstract: The Plasma-Therm continuous-flow hydride generator (illustrated) is based on the NaBH4 system. The apparatus has been applied in generation of the hydrides of, e.g., As and Se for determination by AAS or ICP-AES Detection limits by AAS are 0.04 and 0.07 ng mL-1 for As and Se, respectively, and response is rectilinear for up to 80 or 120 ng mL-1 of As or Se, respectively. The apparatus requires comparatively little operator expertise; it can accept and relay signals to an external computer, so facilitating control and data handling.
Spectrophotometry Spectrophotometry Ultratrace

"Flow Injection Hydride Generation Atomic Absorption Spectrometry With A Gas Diffusion Unit Using A Microporous PTFE Membrane"
J. Flow Injection Anal. 1985 Volume 2, Issue 2 Pages 134-142
Manabu YAMAMOTO, Makoto YASUDA, Yuroku YAMAMOTO

Abstract: Performance of a newly made gas diffusion unit with porous PTFE tubing was examined as a gas-liquid separator of FIA manifold for hydride generation-atomic absorption spectrometry. Arsine generated from 0 to 10 ppb of arsenic was separated quantitatively from the sample solutions, when the length of porous PTFE tubing (ID: 3 mm, porosity: 70% ) is longer than 50 cm. Arsenic lower than 2 ppb, which corresponds to the concentration level of arsenic in seawater could be determined directly with a sample volume of 1 mL. Sample throughput was 150/h.
Sea Spectrophotometry Gas diffusion Teflon membrane

"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.
Blood Urine Environmental Leaves Waste Rain Water Spectrophotometry Spectrophotometry Amalgamation FIMS Reference material Volatile generation Volatile generation

"Determination Of The Toxicological-relevant Arsenic Content In Urine"
LaborPraxis 1998 Volume 22, Issue 11 Pages 18-22
Baasner, J.;Guo, T.Z.;Tsalev, D.L.

Abstract: A combination of the flow injection technique with the hydride AAS was applied to determine toxicol. relevant total As content in urine. L-Cys was used as preredn. agent. The detection limit was 1 µg/mL urine. A precision of 2% was found at a concentration. of 3 µg/mL.
Urine Spectrophotometry

"Coupling Of Microwave Digestion And Hydride AAS"
LaborPraxis 1993 Volume 17, Issue 4 Pages 44-48
Meyer, A.;Schwedt, G.

Abstract: An automated system is described for the interference-free determination of As and Se in protein-containing samples (serum and urine) without the need for sample separation. In the flow injection system, the sample is pumped with a digestion reagent through a coil in a microwave apparatus ('Maxidigest') and the product is injected into a stream of HCl carrier and reacted with sodium borohydride. After gas-liquid separation, the hydride gas is subjected to AAS. Optimization of the system is discussed.
Blood Serum Urine Sample preparation Spectrophotometry Microwave Automation Online digestion Interferences Phase separator Optimization

"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).
Environmental Food Water Spectrophotometry Cold trap Reference material

"A Critical Survey Of Hydride Generation Techniques In Atomic Spectroscopy"
Pure Appl. Chem. 1992 Volume 64, Issue 2 Pages 227-244
A. D. Campbell

Abstract: A review with 134 references. Formation of the hydrides of antimony, arsenic, bismuth, germanium, lead, selenium, tellurium and tin by reaction with sodium tetrahydroborate(III) affords an excellent method for the separation of these elements as gases from a wide range of matrixes. Excellent low limits of detection are attained when this separation method is combined with atomization of the hydride in a heated quartz tube in the optical axis of a conventional atomic absorption spectrometer but there are many interferences to contend with both at the hydride generation stage and in the atomization process. Hydride generation is also used in conjunction with inductively coupled plasma (ICP) emission spectrometers. It is particularly useful for the determination of arsenic and selenium which suffer considerable spectral interferences caused by radicals in flame atomic absorption spectrometry. Implications of recent advances in the application of this separation procedure for the determination of hydride forming elements by atomic absorption and also ICP atomic emission spectrog. techniques are discussed.
Spectrophotometry Spectrophotometry Review Volatile generation Interferences Volatile generation

"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.
Biological Environmental Spectrophotometry Speciation

"Pneumatic Nebulizer As A Dilution Chamber In A Flow Injection System For Multielement Analysis By ICP-MS"
Quim. Nova 1998 Volume 21, Issue 4 Pages 405-409
Gomes Neto, Jos&eacute; Anchieta; Silva, Jos&eacute; Bento B.; Rodrigues Neto, Renato; Curtius, Adilson Jos&eacute;; Souza, Ivan G.

Abstract: An automatic dispenser based on a flow injection system used to introduce sample and anal. solution into an inductively coupled plasma mass spectrometer through a spray chamber is proposed. Anal. curves were constructed after the injection of 20 to 750 µL aliquots of a multielement standard solution (20.0 µg L-1 in Li, Be, Al, V, Cr, Mn, Ni, Co, Cu, Zn, As, Se, Sr, Ag, Cd, Ba, Tl, Pb) and the acquisition of the integrated transient signals. The linear concentration. range could be extended to ~five decades. The performance of the system was checked by analyzing a NiST 1643d reference material. Accuracy could be improved by the proper selection of the injected volume Besides good precision (relative standard deviation <2%), the results obtained with the proposed procedure were closer to the certified values of the reference material than those obtained by direct aspiration or by injecting 125 µL of several anal. solutions and samples.
NIST 1643 Mass spectrometry Dilution Nebulizer Reference material

"Determination Of Trace Arsenic And Mercury In Drink By Hydride Generation-ICP-AES"
Sichuan Daxue Xuebao (Ziran Kexue Ban) 1996 Volume 33, Issue 4 Pages 419-423
Hu, M.;Huang, Q.;Xia, H.;Tong, S.

Abstract: A method for simultaneous determination of trace concentrations of As and Hg in drink have been investigated by continuous-flow mode hydride generation and inductively coupled plasma atomic emission spectrometry. The influence of operating conditions on the result of analysis is discussed. The proposed method is sensitive, accurate and easy to operate. The relative standard deviation is less than 5% if the concentration is 0.05-0.1 mg/L. The recovery of standard addition is 87-100%.
Beverage Spectrophotometry Standard additions calibration

"Determination Of Arsenic, Antimony And Bismuth In Geological Samples By Atomic Absorption Spectrometry With Continuous-flow Hydride Generator"
Yejin Fenxi 1993 Volume 13, Issue 2 Pages 11-14
Guo Xiaowei, Tong Kaiyuan

Abstract: A simple continuous-flow hydride generator is designed and its construction is described. By using the device, the precisions and detection limits of As, Sb, Bi, Se, Te and Hg are tested, and the results obtained agreed with the literature values. An analytical method for determining As, Sb and Bi in geological samples and standard reference samples is reported.
Geological Spectrophotometry Volatile generation Reference material Volatile generation

"Determination Of Trace Arsenic In Spirulina Plaensis Tablets By Flow Injection Hydride Generation Atomic Fluorescence Spectrometry"
Zhongguo Yaoke Daxue Xuebao 1998 Volume 29, Issue 6 Pages 473-474
Dong Shunling

Abstract: A method for determination of trace arsenic in Spirulina plaensis tablets by flow injection hydride generation atomic fluorescence spectrometry was developed. Digesting sample with HNO3-H2SO4-HCIO4 (20: 1: 1) mixed acid, and potassium iodide and ascorbic acid were chosen as the interference suppressing agents. The characteristic concentration. (0.0044 absorption) was 0.2 ng/ ml, the average recovery was 96 .6% (n=5, RSD=2. 8%), within 1. 0~5. 0 ng/ ml, arsenic had a good linearity, and the least square equation is y=0.205x-0. 0001 (r=0. 9994, n=5).
Pharmaceutical Fluorescence Interferences

"Determination Of Traces Of Arsenic And Selenium By Hydride Generation-atomic Absorption Spectrometry"
Fresenius J. Anal. Chem. 1985 Volume 321, Issue 5 Pages 464-466
Hisatake Narasaki

Abstract: Hydrides evolved in the mixing coil were stored at a pressure of up to 0.4 atm in a separating funnel and swept into an electrically heated furnace. This process caused effective reduction of the hydride forming elements and minimized the consumption of the reagents. A decrease in the sensitivity by deterioration of the furnace was not observed, because traces of water were introduced into it. The sensitivities at 1% absorption for As(V) and Se(IV) were 0.2 ppb and 0.6 ppb, respectively. Accuracies checked with biological standard reference materials were within the certified values. The proposed method was applied for the determination of arsenic and selenium in river water.
River Spectrophotometry Volatile generation

"Comparative Study Of Atomic Fluorescence Spectroscopy And Inductively Coupled Plasma Mass Spectrometry For Mercury And Arsenic Multispeciation"
Anal. Bioanal. Chem. 2005 Volume 382, Issue 2 Pages 485-492
Jos&eacute; Luis G&oacute;mez-Ariza, Fernando Lorenzo, Tamara Garc&iacute;a-Barrera

Abstract: Mercury and arsenic are two elements of undoubted importance owing to their toxic character. Although speciation of these elements has been developed separately, in this work for the first time the speciation of As and Hg using two atomic fluorescence detectors in a sequential ensemble is presented. A coupling based on the combination of high-performance liquid chromatography (where mercury and arsenic species are separated) and two atomic fluorescence detectors in series, with several online treatments, including photooxidation (UV) and hydride generation, has allowed the determination of mercury and arsenic compounds simultaneously. The detection limits for this device were 16, 3, 17, 12 and 8 ng mL-1 for As(III), monomethylarsinic acid, As(V), Hg2+ and methylmercury, respectively. This coupling was compared with an analogous one based on inductively coupled plasma-mass spectrometry (ICP-MS) detection, with detection limits of 0.7, 0.5, 0.8, 0.9 and 1.1 ng mL-1, respectively. Multispeciation based on ICP-MS exhibits better sensitivity than the coupling based on tandem atomic fluorescence, but this second device is a very robust system and exhibits obvious advantages related to the low cost of acquisition and maintenance, as well as easy handling, which makes it a suitable system for routine laboratories.
Fluorescence HPLC Mass spectrometry Speciation Sequential injection UV reactor Simultaneous analysis Detection limit Sensitivity Low cost Method comparison Photochemistry Volatile generation

"Determination Of Arsenic In Chinese Herbal Extract By Flow Injection-hydride Generation-atomic Absorption Spectrometry"
Zhongguo Yaoke Daxue Xuebao 2003 Volume 34, Issue 4 Pages 48-50
DENG Shi-Lin , LI Xin-Feng, DENG Fu-Liang, LIANG Shao-Xian

Abstract: AIM: To investigate the various test conditions and effect factors for determination of arsenic by flow injection-hydride generation-atomic absorption spectrometry(FI-HG-AAS) and to develop a method for the determination of arsenic in Chinese herbal extract by flow injection-hydride generation-atomic absorption spectrometry. METHOD: Flow injection-hydride generation-atomic absorption spectrometry. RESULT: The detection limit for arsenic was 0.56 ?g/L under optimum conditions. The linear range was 0.6-30 ?g/L. The relative standard deviation was less than 5% and the recoveries was 91%-103%. This method has been applied to the determination of arsenic in Chinese herbal extract with satisfactory results. CONCLUSION: This method overcame the problems of slow analysis procedure, large sample consuming amount, complex operation and error easily caused by manual injection speed and injection volume in traditional interval hydride generation-atomic absorption spectrometry. It is simple, rapid, highly sensitive and automatic method.