Speciation analysis of mercury in water samples by cold vapor atomic absorption spectrometry after preconcentration with dithizone immobilized on microcrystalline naphthalene
(1) Department of Chemistry, Yazd University, Yazd, Iran
Abstract:
Trace amounts of inorganic mercury (Hg2+) and methylmercury cations (MeHg2+) were adsorbed quantitatively from acidic aqueous solution onto a column packed with immobilized dithizone on microcrystalline naphthalene. The trapped mercury was eluted with 10 ml of 7 mol L–1 hydrochloric acid solution. The Hg2+ was then directly reduced with tin (II) chloride, and volatilized mercury was determined by cold vapor atomic absorption spectrometry (CVAAS). Total mercury (Hgt) was determined after decomposition of MeHg+ into Hg2+. Hg2+ and MeHg+ cations were completely recovered from the water with a preconcentration factor of 200. The relative standard deviation obtained for eight replicate determinations at a concentration of 0.3 g L–1 was 1.8%. The procedure was applied to analysis of water samples, and the accuracy was assessed via recovery experiment.