Determination of Arsenic and Mercury Synchronously in Soils with Dual-Channel Atomic Fluorescence Spectrometry

Study was carried out on how to determine total arsenic and mercury synchronously, and screen out an optimal digestion system. Test conditions were optimized with the orthogonal test designing method. A new method of determining total arsenic and mercury in 10% hydrochloric acid solution using the dual channel atomic fluorescence spectrometry was set up for soil samples digested in aqua regia. The method has a wide linear range (As 0 ~ 200 μg/L and Hg 0 ~ 10 μg/L) and low detection limits (As 0.05 μg/L and Hg 0.007 μg/L). The recovery rate varied from 96.0% to 101.0% for As and from 97.0% to 103.7% for Hg in soils, whereas the RSD (n=6) of arsenic was 2.7% and of mercury 4.5%. The method is accurate, rapid and convenient and produces satisfactory results.