土壤中不同形态砷的分析方法  

Speciation Analysis of Arsenic in Soil Samples

作　　者：张静[1] 刘晓端[1] 江林[1] 

机构地区：[1]国家地质实验测试中心,北京100037

出　　处：《岩矿测试》2008年第3期179-183,共5页Rock and Mineral Analysis

摘　　要：选取磷酸作为提取剂,比较了超声和水浴两种方法辅助提取土壤中不同形态的砷,离子色谱一氢化物发生原子荧光光谱联用法(IC-HGAFS)测定砷的4种形态,即As(Ⅲ)、As(Ⅴ)、MMA (甲基胂酸)和DMA(二甲基胂酸)。从测定结果可以看出,水浴的提取效果明显高于超声的提取效果。土壤中砷以无机态为主,而无机态砷又以As(Ⅴ)为主,没有检测到有机砷。测定土壤中各种形态砷的加标回收率为72.0%～105.4%,相对标准偏差(RSD,n=5)为2.61%～8.19%。A new method for analysis of four arsenic species of As（Ⅲ）, As（ Ⅴ）, methanearsonic acid （MAA） and dimethyl arsenic acid （DMA） in soil samples was developed. Phosphoric acid was chosen as the extractant and two techniques of ultrasonic wave and water bath were used for extracting the arsenic species from soil samples. Ion chromatography-hydride generation-atomic fluorescence spectrometry was used for the determination of arsenic species. The recovery of the method was 72.0% - 105.4% with precision of 2.61% - 8.19% RSD （ n = 5）. The analytical results from the study showed that the extraction efficiency by water bath was remarkably superior to that by ultrasonic wave. And the results also showed that the main arsenic species in soils were inorganic arsenic such as arsenate and arsenite, in which As（Ⅴ） was in abundant and no organic arsenic was detected.

关 键 词：超声提取 水浴提取 离子色谱-氢化物发生原子荧光光谱法 砷形态 土壤 

分 类 号：O652.6[理学—分析化学] O655.6[理学—化学]