微波消解-原子荧光光谱法测定化探样品中的砷和锑

Determination of arsenic and antimony in geochemical samples by microwave digestion-atomic fluorescence spectrometry

准确测定砷和锑的含量是化探样品测定中的重要内容。本文介绍了测定这两种元素的一种新方法,笔者基于原子荧光光谱仪,试样经氢氟酸-盐酸-硝酸混酸微波消解,高氯酸-硫酸混酸蒸发除去氢氟酸,由盐酸-酒石酸混合溶液定容,从而得到样品中准确的砷、锑含量。本方法砷、锑校准曲线的线性相关系数均大于0.999;检出限分别为砷0.039μg/L、锑0.0058μg/L。按照实验方法测定水系沉积物、土壤标准物质中砷、锑,结果的相对误差砷为1.52%~6.77%,锑为1.25%~7.17%;相对标准偏差(RSD,n=6)砷为2.27%~5.15%、锑为1.88%~5.81%。本方法适用于化探样品中砷含量在0.05~500μg/g、锑含量在0.05~300μg/g之间的样品测定。

Accurate determination of Arsenic and Antimony is an important content in the determination of geochemical samples.A new method to determin the two elements is proposed in this paper.Based on the atomic fluorescence spectrometer,the sample was digested by microwave digestion of hydrofluoric acid-hydrochloric acid-nitric acid mixture,evaporated by perchloric acid-sulfuric acid mixture to remove hydrofluoric acid,and was volume-stabilized by hydrochloric acid-tartaric acid mixture solution,thus obtaining the accurate content of arsenic and antimony in the sample.The linear correlation coefficients of the calibration curves of arsenic and antimony in this method are greater than 0.999,and the detection limits are 0.046μg/L for arsenic and 0.0072μg/L for antimony,respectively.The relative errors of arsenic and antimony in stream sediments,soil reference materials GBW07302 a and GBW07446 were 1.52%~1.61%and 1.25%~3.57%respectively,and the relative standard deviations(RSD,n=6)were 2.27%~2.42%and 1.88%~2.51%respectively.This method is suitable for the determination of arsenic(0.05~500μg/g)and antimony(0.05~300μg/g)in geochemical samples.