Simultaneous Determination of As and Hg in Environmental Water by HG-AFS

HG-AFS was applied to the simultaneous determinations of arsenic and mercury in environmental water. Hydrides of As and atomic Hg were generated from HCl (5+95) solution by reacting with 15 g·L-1 KBH4 solution (dissolved in 10 g·L-1 KOH solution). Flow-rates of 400 mL·min-1 for carrier gas and 800 mL·min-1 for shielding gas were taken in the analysis. Solution of thiourea was added to the water sample as pre-reductant. One mL of sample solution was introduced and operated under the prescribed working condition of the instrument. Linear relationships between the fluorescence intensity and mass concentration of As and Hg found were in the ranges of 0.50-50.0 and 0.05-5.00 μg·L-1, with detection limits (3S/N) of 0.045 μg·L-1 and 0.011 μg·L-1, respectively. The proposed method was applied to the analysis of samples of environmental water, giving values of recovery found were 96.8%-100.4% for As and 98.6%-100.2% for Hg.