Departament de Química, Universitat de Lleida, and AGROTECNIO, Rovira Roure 191, 25198 Lleida, Catalonia, Spain.
Departament de Química, Universitat de Lleida, and AGROTECNIO, Rovira Roure 191, 25198 Lleida, Catalonia, Spain.
Sci Total Environ. 2018 Jan 15;612:269-275. doi: 10.1016/j.scitotenv.2017.08.200. Epub 2017 Sep 1.
Indium is increasingly used in electronic devices, from which it can be mobilized towards environmental compartments. Speciation of In in waters is important for its direct ecotoxicological effects, as well as for the fate of this element in the environment (e.g. fluxes from or towards sediments). Free indium concentrations in the environment can be extremely low due to hydrolysis, especially important in trivalent cations, to precipitation and to complexation with different ligands. In this work, the free indium concentration (which is a toxicologically and geochemically relevant fraction) in aqueous solutions at pH3 has been measured with an adapted version of the electroanalytical technique AGNES (Absence of Gradients and Nernstian Equilibrium Stripping). Speciation measurements in mixtures of indium with the ligands NTA (nitrilotriacetic acid) and oxalate indicate that the values of their stability constants in the NIST46.6 database are less adequate than those published in some more recent literature. The extraordinary lability and mobility of In-oxalate complexes allow the measuring of free indium concentrations below nmol/L in just 25s of deposition time.
铟在电子设备中的应用越来越广泛，而它可能会从这些设备中迁移到环境介质中。水中铟的形态对于其直接的生态毒理学效应以及该元素在环境中的归宿（例如，从沉积物或向沉积物的通量）都非常重要。由于水解作用，环境中的游离铟浓度可能极低，尤其是在三价阳离子中，还会发生沉淀和与不同配体的络合。在这项工作中，采用改良的电分析技术 AGNES（无梯度和能斯特平衡萃取）测量了 pH3 水溶液中的游离铟浓度（这是一个具有毒理学和地球化学相关性的分数）。在铟与配体 NTA（氮三乙酸）和草酸盐的混合物中的形态测量表明，其在 NIST46.6 数据库中的稳定常数值不如一些更新的文献中公布的值准确。草酸盐配合物中铟的非凡不稳定性和迁移性使得仅在 25 秒的沉积时间内就可以测量出低至纳摩尔/升的游离铟浓度。
