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

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Classification: Plant -> leaves

Citations 2

"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.
Arsenic Selenium Spectrophotometry Reference material Chelex

"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.
Arsenic Bismuth Germanium Antimony Selenium Tellurium Tin Spectrophotometry Interferences Volatile generation Reference material Volatile generation