高效液相色谱-原子荧光光谱联用分析土壤中形态砷

采用高效液相色谱(HPLC)-原子荧光光谱(AFS)联用技术分析土壤中亚砷酸盐As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐As(Ⅴ)]等4种形态砷,以磷酸为提取剂、抗坏血酸为还原剂,优化了水浴提取条件。As(Ⅲ)、DMA、MMA和As(Ⅴ)在7 min之内实现了完全分离,在1.00μg/L～100μg/L范围内线性良好,实验室检出限分别为0.25μg/L、0.36μg/L、0.39μg/L和0.51μg/L,土壤标准样品平行测定的RSD≤7.4%,加标回收率为79.5%～95.0%,提取率为74.6%～90.4%。

Speciation Analysis for Arsenic in Soils by HPLC-AFS

A method was established for determination of four arsenic forms such as As（Ⅲ）,methanearsenic acid（MMAV）,dimethyl arsenic acid（DMAV） and As（Ⅴ） in soil samples by high performance liquid chromatography（HPLC）-hydride generation（HG）-atomic fluorescence spectrophotometry（AFS）.Phosphoric acid was used as extractive solution,Ascorbic acid as reducing agent.In optimized conditions,samples were bathed in water for extracting different arsenic forms before the determination.The four arsenic forms were separated in 7 min.The good linearity of four arsenic forms was obtained in range from 1.00 μg/L to 100 μg/L,the laboratory detection limits for As（Ⅲ） 0.25 μg/L,DMAV 0.36 μg/L,MMAV 0.39 μg/L and As（Ⅴ） 0.51 μg/L respectively,relative standard deviation of duplicates of soil reference materials≤7.4%,spiked recoveries between 79.5% and 95.0%,extractive rate from 74.6% to 90.4%.