微波辅助萃取-HG-AFS测定土壤中无机砷

Determination of inorganic arsenic in soil with microwave assisted extraction coupled with hydride generation-atomic fluorescence spectrometry

采用微波辅助萃取分析物，联合原子荧光光谱技术，建立了微波辅助萃取-HG-AFS测定土壤中无机砷的分析方法。用正交试验设计结合单因素试验优化了样品粒度、萃取温度、萃取时间、固液比等微波萃取条件，研究了共存离子对无机砷测定的干扰情况。方法的线性范围为1．0～160．0μg/L，无机砷的检出限为0．20μg/L，相对标准偏差为0．3％，样品回收率为93．0％～98．5％。用本法分析3个不同产地有代表性土壤中无机砷量。

Inorganic arsenic in soil was extracted by microwave assisted extraction （MAE） and determined by HG- AFS. The MAE operating conditions were optimized by the orthogonal test design combined with the mono-factor test. The interference which is from concomitant ions on inorganic arsenic has been eliminated by adding ascorbicacid-thiourea-citricacid. The linear range of the calibration curve for inorganic arsenic was 1.0 - 160.0 μg/L. The detection limit was 0.20 μg/L and the RSD was 0.3%. The recoveries of inorganic arsenic in soil samples were 93.0% ～98.5 %. The method was successfully applied to the extraction and determination of inorganic arsenic in soil samples from different regions.