Bissen M, Frimmel F H
Engler-Bunte-Institut, Chair for Water Chemistry, Universität Karlsruhe, Germany.
Fresenius J Anal Chem. 2000 May;367(1):51-5. doi: 10.1007/s002160051597.
A method to separate and quantify two inorganic arsenic species As(III) and As(V) and two organic arsenic species, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), by HPLC-ICP/MS has been developed. The separation of arsenic species was achieved on the anionic exchange column IonPac AS11 (Dionex) with NaOH as mobile phase. The technique was successfully applied to analyze extracts of two contaminated soils, sampled at a former tannery site (soil 1) and a former paint production site (soil 2). The soils were extracted at pH values similar to the natural environment. Extractions were performed at different pH values with 0.3 M ammonium oxalate (pH = 3), milli-Q water (pH = 5.8), 0.3 M sodium carbonate (pH = 8) and 0.3 M sodium bicarbonate (pH = 11). No organically bound arsenic was found in the extracts. As(V) was the major component. Only up to 0.04% of the total arsenic contained in soil 1 were mobilized. The highest amount of extracted arsenic was found at the highest pH. In the milli-Q water extract of soil 1 As(III) and As(V) were found. High amounts of As(V) were found in the extracts of soil 2. Up to 20% of the total arsenic bound to soil 2 constituents were released. The results show that the mobilization of arsenic depended on the pH value of the extraction solution and the kind of extracted soil. Dramatic consequences have to be expected for pH changes in the environment especially in cases where soils contain high amounts of mobile arsenic.
已开发出一种通过高效液相色谱-电感耦合等离子体质谱法（HPLC-ICP/MS）分离和定量两种无机砷物种As(III)和As(V)以及两种有机砷物种，即一甲基胂酸（MMA）和二甲基胂酸（DMA）的方法。砷物种的分离是在阴离子交换柱IonPac AS11（戴安公司）上以氢氧化钠作为流动相实现的。该技术已成功应用于分析在一个 former tannery site（土壤1）和一个 former paint production site（土壤2）采集的两种受污染土壤的提取物。土壤是在与自然环境相似的pH值下进行提取的。分别使用0.3 M草酸铵（pH = 3）、超纯水（pH = 5.8）、0.3 M碳酸钠（pH = 8）和0.3 M碳酸氢钠（pH = 11）在不同pH值下进行提取。提取物中未发现有机结合态砷。As(V)是主要成分。土壤1中仅动员了高达0.04%的总砷。在最高pH值下发现提取的砷量最高。在土壤1的超纯水提取物中发现了As(III)和As(V)。在土壤2的提取物中发现了大量的As(V)。与土壤2成分结合的总砷中高达20%被释放出来。结果表明，砷的动员取决于提取溶液的pH值和被提取土壤的类型。对于环境中的pH值变化，尤其是在土壤中含有大量可移动砷的情况下，必须预期会产生重大后果。
