Abstract A method for computing the selectivity (S) of reagents designed for dissolving the mobile heavy metal (HM) compounds in soils is proposed. Phytoavailability of HM is higher than the selectivity of reagents with respect to their mobile compounds, since plants absorb the metals from compounds with different stability. The object of study was Haplic Chernozem and Calcic Kastanozems artificially contaminated with the Pb, Cu and Zn acetate in a 2-year-long model experiment. Selectivity of reagents depends strongly upon the compositional alterations of HM compounds during the interaction of metal-pollutants with the contaminated soil. The acetate‒ammonia buffer (AAB) demonstrates the highest selectivity with respect to the mobile Pb, Cu and Zn compounds in the studied soils. Temporal intensification of the crystallisation of the introduced metal-pollutant salts influences differently on their dissolution by the reagents. Reinforcement of the newly formed metal compounds hampers their dissolution in the AAB, resulting in enhancement of the selectivity of reagent. Selectivity of the EDTA + AAB reagent with respect to these metals was lower and decreased in the course of their interaction with soils.

中文翻译：

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从土壤中提取重金属流动化合物的试剂选择性计算方法

摘要 提出了一种计算用于溶解土壤中移动重金属 (HM) 化合物的试剂的选择性 (S) 的方法。HM 的植物利用率高于试剂对其流动化合物的选择性，因为植物从具有不同稳定性的化合物中吸收金属。研究对象是在为期 2 年的模型实验中人工污染了醋酸铅、铜和锌的 Haplic Chernozem 和钙钙钙锌矿。试剂的选择性在很大程度上取决于金属污染物与受污染土壤相互作用期间 HM 化合物的组成变化。醋酸氨缓冲液 (AAB) 对所研究土壤中的移动 Pb、Cu 和 Zn 化合物表现出最高的选择性。引入的金属污染物盐的结晶的时间强化对它们被试剂溶解的影响不同。新形成的金属化合物的增强阻碍了它们在 AAB 中的溶解，从而提高了试剂的选择性。EDTA + AAB 试剂对这些金属的选择性较低，并在它们与土壤相互作用的过程中降低。