硫代砷化物的合成、鉴定和定量分析方法研究

制备了4种硫代砷酸盐,采用电喷雾-高分辨质谱( ESI-HR-MS )进行鉴定,确证为一硫代砷酸盐( Hn AsSOn-33)、二硫代砷酸盐( Hn AsS2 On-32)、三硫代砷酸盐( Hn AsS3 On-3)和四硫代砷酸盐( Hn AsS4 n-3)。以合成的硫代砷酸盐为标准品,建立了基于离子色谱-电感耦合等离子质谱( IC-ICP-MS)同时测定4种硫代砷酸盐、亚砷酸盐和砷酸盐的方法。本方法线性范围为3.3~833μg/L,线性相关系数R2>0.99,方法检出限为0.4~25μg/L。本研究合成的硫代砷酸盐标准物质及建立的定量分析方法,对后续富含硫化物的天然水体中不同形态砷的迁移和转化研究具有重要意义。

Synthesis,Identification and Quantitative Analysis of Aqueous Thioarsenates

Four kinds of thioarsenates, HnAsSO3n-3, HnAsS2O2n-3, HnAsS3On-3 and HnAsS4n-3, were synthesized and identified by electrospray ionization-high resolution mass spectrometry ( ESI-HR-MS ) . With the synthetic thioarsenates as standards, a quantitative analytical method based on ion chromatograph-inductively coupled plasma mass spectrometry ( IC-ICP-MS ) was set up to simultaneously determine the concentrations of arsenite, arsenate, mono-thioarsenate, di-thioarsenate, tri-thioarsenate, and tetra-thioarsenate in water. The linear range of the method was from 3. 3 μg/L to 833 μg/L with the correlation coefficients higher than 0. 99, and the detection limits were between 0. 4 μg/L and 25 μg/L. The synthetic standard materials of thioarsenates and the quantitative analysis method established in this study are of great significance for future investigations on the environmental transportation and transformation of various arsenic species derived from natural sulfidic waters.