离子色谱氢化物发生原子荧光法测定地下水中砷形态

采用离子色谱氢化物发生原子荧光联用法(IC-HGAFS)测定四种砷形态,并优化了各种实验参数。整套分析系统的最小检出量为As(III)0.020ng,MMA 0.045ng,DMA0.043ng,As(V)0.166ng,相对标准偏差(n=6)小于3%,在10~200 ng/mL的浓度范围内线性关系均大于0.999。用此方法测量地下水的4种砷形态加和的总量与用HG-AFS测得的总砷值相一致,表明本方法切实可行。本系统结构简单、稳定性好,非常适合用于检测砷形态。

Determination of arsenic species in groundwater by Ion chromatography-hydride generation-atomic fluorescence spectrometry

The determination of arsenite(As(III)),arsenate(As(V)),monomethylarsonic(MMA) and dimethylarsinic acid(DMA) was performed with ion chromatography-hydride generation-atomic fluorescence spectrometry(IC-HG-AFS).Various experimental parameters were optimized,such as parameters of chromatography,hydride generation and atomic fluorescence spectrometry.With a sample loading volume of 20 microliter,the measurable minimum for As(III),DMA,MMA and As(V) were 0.02ng,0.045ng,0.043ng,0.166ng,respectively,and relative standard deviations were less than 3%(n=6).Correlation coefficients were greater than 0.999 in the range of 10～200ng/mL.The present procedure was applied for the speciation of arsenic in underground water,and the sum of the four arsenic species by IC-HGAFS was in good agreement with the total value by HG-AFS.This simple system is very suitable for the detection of arsenic species.