微波辅助提取-液相色谱-氢化物发生-原子荧光光谱法分析沉积物中砷的形态

采用微波辅助提取-液相色谱-氢化物发生-原子荧光光谱法(LC-HG-AFS)联用技术分析了太湖沉积物中砷的形态亚砷酸(As(III))、二甲基砷酸钠(DMA)、一甲基砷酸二钠(MMA)和砷酸As(V)]。测得沉积物中以无机砷为主,且以As(V)居多。选定以1mol/L的磷酸和0.1mol/L抗坏血酸为提取液,在微波辅助萃取(功率为60W,时间12min)下,萃取率达79.84%～91.57%,回收率在94.78%～107.6%之间。4种砷的形态在0～160μg/L之间时线性良好,检测限为0.6～2.3μg/L,相对标准偏差RSD为1.62%～2.20%。方法具有简便、快速、灵敏的特点。

Speciation of Arsenic in the Sediments of Tai Lake by Microwave-Assisted Extraction High Performance Liquid Chromatography and Hydride Generation-Atomic Fluorescence Spectrometry

Based on microwave-assisted extraction-liquid chromatography and hydride generation-atomic fluorescence spectrometry,an analytical method for speciation of arsenic containing compound(arsenite As(III),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA) and arsenate As(V)) in the Tai lake sediment was developed.The results showed that the main speciation in sediments is inorganic arsenic and arsenate As(V) is the majority of the speciation.This paper chose 1 mol/L phosphoric acid as extracting solution and the microwave-assisted extraction was conducted for 12 mins with a power of 60 W.The extraction rates were in the range of 79.84%~91.57%.The linear responses for four arsenic species were in the range of 0~160 μg/L with the limits of detection in the range of 0.6~2.3 μg/L,and the recovery rates in the range of 94.78%~107.6%.The developed method is simple,rapid and sensitive,and may be applicable for arsenic speciation in other sediments or soil samples.