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

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BCR 144

Citations 3

"Analytical Characteristics Of An Inductively Coupled Plasma Mass Spectrometer Coupled With A Thermospray Nebulization System"
J. Anal. At. Spectrom. 1995 Volume 10, Issue 9 Pages 575-581
Hans Vanhoe, Steven Saverwijns, Magali Parent, Luc Moens and Richard Dams

Abstract: The effects of different matrix salts and mineral acids on analyte ion signals in ICP-MS was evaluated using the thermospray (TS) sample introduction system of Vanhoe et al. (Ibid., 1994, 99, 815). The results were compared with two other sample introduction systems, the pneumatic nebulizer coupled with a spray chamber (the conventional arrangement; CA) and the same nebulizer coupled with the desolvating unit employed with the thermospray nebulizer. Studies were effected with a 10 µg/l multi-element solution of Be, Al, Sc, Co, In, Gd, Tl, Th and U in 0.14 M HNO3 containing 1-5000 mg/l of the matrix elements Na, Ca, P and S (ICP-MS operating conditions tabulated). Non-spectroscopic interferences from Na and Ca were more pronounced for the TS system than the CA but were almost the same for P and S. The TS system was used for the analysis of Cd and Pb in three environmental reference materials (Community Bureau of Reference (BCR) Certified Reference Materials 141R Soil- calcareous loam, 144R sewage sludge-domestic and 146R sewage sludge-industrial, following digestion with aqua regia (experimental details given). A sample flow injection system was used to eliminate memory effects. Results obtained with the TS system agreed more closely with certified values than those obtained with the CA system.
Cadmium Lead Mass spectrometry Sample preparation Reference material Method comparison Interferences

"Immobilized Cyanobacteria For Online Trace Metal Enrichment By Flow Injection Atomic Absorption Spectrometry"
Anal. Chem. 1994 Volume 66, Issue 21 Pages 3632-3638
Angel Maquieira, Hayat A. M. Elmahadi, and Rosa Puchades

Abstract: Cyanobacteria (Spirulina platensis) immobilized on controlled pore glass pre-concentrate Cu(II), Zn(II), Cd(II), Pb(II), and Fe(III) from aqueous solution with high efficiency as ascertained using an online flow injection atomic absorption spectrometry system. The degree of metal binding depends on the pH of the solution. Quantitative retention of copper, zinc, and cadmium occurred at a wide range of pH values, while the retention for lead and iron was pH-dependent. The latter metals were adsorbed strongly only at pH 6 and 7, respectively. The breakthrough capacity was determined from the breakthrough curve, with values of 0.0035, 0.0008, 0.0011, 0.0028, and 0.0017 ng/mL for Cu, Zn, Cd, Pb, and Fe, respectively, being obtained. The analysis of a certified reference sample, sewage sludge of domestic origin (BCR No. 144), for cadmium and copper with a high accuracy ensures the feasibility of this technique for environmental analysis. Copyright 1994, American Chemical Society.
Copper Cadmium Lead Iron Spectrophotometry Immobilized cell Preconcentration pH Controlled pore glass Reference material

"Use Of Solid-phase Extraction To Eliminate Interferences In The Determination Of Mercury By Flow-injection CV AAS"
Anal. Bioanal. Chem. 2003 Volume 377, Issue 4 Pages 735-739
Agnieszka Krata, Krystyna Pyrzyńska and Ewa Bulska

Abstract: Solid-phase extraction with two-step elution has been developed for effective elimination of copper and iron interference with mercury determination by flow-injection cold vapor atomic absorption spectrometry (CV AAS). Sodium tetrahydroborate(III) was used as reducing agent. Cation-exchanger Dowex 50Wx4 was applied for the sorption of mercury and both interfering ions. In the first step elution of Cu(II) and Fe(III) was performed using 0.5 mol L-1 KF solution. Then mercury was eluted with 0.1% thiourea in 8% HCl. The detection limit (3s) for Hg(II) was 27 ng L-1. The expanded uncertainty estimated for the whole procedure was about 6%. The accuracy of the proposed method was evaluated by determination of the recovery of known amount of mercury added to mineral, spring, and tap waters, and by analysis of a certified reference material BCR-144R (sewage sludge).
Mercury Spectrophotometry Solid phase extraction Dowex Interferences