H^+反应对土壤重金属分级提取形态分析的影响

Effect of H^+ ion reactivity on sequential extraction procedures of heavy metal speciation analysis

探讨了普遍存在于重金属分级提取形态分析体系中的H+反应的影响因素,分析了H+反应与提取剂的选择性、金属离子的重分配现象的关系,以及H+反应对分级提取法数据结果的影响,并对分级提取方法作了进一步的改进。研究表明提取剂pH、提取体系、土壤理化性质及土壤 溶液比是影响H+反应的主要因素;H+反应可降低提取剂选择性,减弱金属离子的重分配能力,影响分析结果的有效性,且对于不同的重金属离子、不同的提取体系,H+反应所造成的影响不同。

Firstly, H^+ ion reactivity, which commonly exists in sequential extraction procedure of heary metal speciation analysis, and affected factors were discussed. Secondly, the relationship between H^+ ion reactivity and the problems of sequential extraction, such as the selectivity of the extractants and redistribution of heary metals, as well as the effect of H^+ ion reactivity on the analytical results were analyzed. Thirdly, some advice on improving the sequential extraction was proposed. The study indicated that H^+ ion reactivity was mainly affected by extractant pH, extraction systems, the characteristics of soil samples and the ratio of soil to salution. H^+ ion reactivity can reduce the selectivity of the extractants and the redistribution ability of metal ions, and further affect the validity of analytical results. H^+ ion reactivity has different effects on different heavy metals and different extraction systems.