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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Citations 2

"Determination Of Cadmium In Environmental Samples By Hydride Generation With In Situ Concentration And Atomic Absorption Detection"
Analyst 1997 Volume 122, Issue 4 Pages 331-336
Henryk Matusiewicz, Mariusz Kopras and Ralph E. Sturgeon

Abstract: A continuous-flow AAS system for Cd determination is described. A Cd solution acidified with HCl was mixed with 1 µg/ml Co and 0.5% thiourea (and also with 0.01 M didodecyldimethyl-ammonium bromide for reaction with KBH4) and diluted to 1 mL with water. The resulting solution was aspirated at a flow rate of 1 ml/min into a continuous-flow system and merged with a stream of either 2% NaBH4 or 4% KBH4 at a flow rate of 1 ml/min. The mixture was passed through a reaction cell/gas-liquid separator maintained at 50°C and the volatile Cd species evolved were carried by an Ar stream on to the inner wall of a GF for in situ pre-concentration at 200°C. Cd analysis was by ET AAS with atomization at 1800°C for 3 s; detection was at at 228.8 nm. The detection limit was 10 ng/l Cd with KBH4 as reagent. RSD were 10^-14% (n = 10). The method was applied to several environmental and biological CRM. The results obtained agreed with the certified values.
Cadmium Spectrophotometry Heated reaction Volatile generation Reference material Phase separator Preconcentration Volatile generation

"Determination Of Total Mercury In Biological Tissues By Flow Injection Cold Vapor Generation Atomic Absorption Spectrometry Following Tetramethylammonium Hydroxide Digestion"
Analyst 1998 Volume 123, Issue 6 Pages 1215-1218
Guanhong Tao, Scott N. Willie and Ralph E. Sturgeon

Abstract: A simple, rapid and reliable method was developed for the determination of total mercury in biological samples. Samples were solubilized by tetramethylammonium hydroxide (TMAH). The organically bound mercury was cleaved and converted to inorganic mercury by online addition of KMnO4. The decomposed mercury together with inorganic mercury originally present in samples was determined by flow injection cold vapor atomic absorption spectrometry after reduction to elemental mercury vapor using NaBH4. A sample throughput of 100 measurements per h was achieved after a 30 min dissolution with TMAH. The relative standard deviation for 20 µg L-1 Hg was 1.3% and the limit of detection was 0.1 µg L-1 (3s). The proposed method was validated by the anal. of a suite of certified marine biological reference materials, DORM-2 (dogfish muscle), DOLT-2 (dogfish liver) and TORT-2 (lobster hepatopancreas), with calibration against simple Hg(II) standards.
Mercury Sample preparation Spectrophotometry Reference material Volatile generation