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: Marine -> fish -> roach

Citations 1

"Determination Of Organomercury And Mercury In Environmental Samples By Flow Injection Atomic Fluorescence Spectrophotometry"
Int. J. Environ. Anal. Chem. 1996 Volume 63, Issue 3 Pages 187-193
S. C. Edwardst; C. L. Macleod; W. T. Corns; T. P. Williams; J. N. Lester

Abstract: Environmental samples (dogfish and liver certified reference materials, eel and roach) were digested by heating for 4 h at 60°C with 20% tetramethylammonium chloride in a closed vessel. The digest was extracted with toluene, centrifuged, and the extract was mixed with 1 mL 1 mM cysteine or -thiosulfate. The aqueous phase was analyzed for organomercury by flow injection AFS. Total Hg was determined after microwave digestion of samples with 30% H2O2/HNO3/H2O. Sample (100 µL) was injected into a stream of water which was mixed with a stream (0.4 ml/min) of 25 g/l potassium peroxodisulfate and 1.2 g/l CuSO4 in 0.25 M H2SO4 for oxidation to Hg2+ in a 0.5 mL reaction coil. The flow then merged with a stream (0.5 ml/min) of 100 g/l SnCl2 in HCl for reduction to Hg(O) in a 1 mL reaction coil. The Hg(O) was carried in Ar (after separation in a gas liquid separator) to a hygroscopic tubular membrane for drying and to the AFS instrument. The calibration graph was linear for 5-1000 µg/l methylmercury ions and the detection limit was 2 µg/l. The RSD (n = 10) at 25 µg/l was 3.7%. The calibration graph for inorganic Hg was linear for 0.05-1000 µg/l and the detection limit was 0.02 µg/l. Extraction efficiences were 70-80%.
Mercury Methylmercury ion Fluorescence Sample preparation Sample preparation Reference material Extraction Phase separator Speciation