Chemistry Department, University of Girona, C/ Maria Aurèlia Capmany, 69, 17003, Girona, Spain; Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona, Spain.
Chemosphere. 2020 Apr;245:125671. doi: 10.1016/j.chemosphere.2019.125671. Epub 2019 Dec 19.
Determining bioavailable trace concentrations of mercury (Hg) in water is still a challenging analytical task. In this study, we report a methodology for determining labile Hg in natural waters using newly developed sorbents. Silicon dioxide at a nanoparticle range (Si-np) and cellulose powder at a microparticle range (Cel-p), both modified with the ionic liquid trioctylmethylammonium thiosalicylate (TOMATS), have been tested as sorbents (sorb-TOMATS) for Hg(II) uptake from solution. These novel sorb-TOMATS materials were characterized, and parameters affecting the uptake were examined. A similar Hg(II) uptake efficiency (97%) and binding capacity (9 mg Hg/g) was obtained for both sorb-TOMATS, while only a 25% of Hg(II) was taken up using non-impregnated materials. Moreover, these sorb-TOMATS were effectively embedded in agarose gel and were tested as a novel binding phase for the Diffusive Gradients in Thin Films (DGT) technique. Research revealed Si(np)-TOMATS sorbent as a suitable binding phase in the DGT technique for Hg(II) measurements, since it also allowed the efficient elution of the bound Hg(II). This new binding phase showed strong linear correlation between the accumulated Hg(II) mass and deployment time, which is in agreement with the DGT principle. In summary, this novel sorbent has a great potential to improve Hg monitoring in natural waters when integrated it in the DGT design.
测定水中的生物可利用痕量汞（Hg）仍然是一项具有挑战性的分析任务。在本研究中，我们报告了一种使用新开发的吸附剂测定天然水中活性汞的方法。二氧化硅纳米颗粒（Si-np）和纤维素粉末微颗粒（Cel-p）均用离子液体三辛基甲基铵硫代水杨酸盐（TOMATS）修饰，被测试为从溶液中摄取 Hg(II) 的吸附剂（吸附-TOMATS）。这些新型的吸附-TOMATS 材料进行了表征，并研究了影响吸附的参数。两种吸附-TOMATS 的 Hg(II) 摄取效率（97%）和结合能力（9 mg Hg/g）相似，而未浸渍的材料仅能摄取 25%的 Hg(II)。此外，这些吸附-TOMATS 被有效地嵌入琼脂糖凝胶中，并作为扩散梯度薄膜（DGT）技术的新型结合相进行了测试。研究表明，Si(np)-TOMATS 吸附剂是 DGT 技术中用于 Hg(II)测量的合适结合相，因为它还允许有效地洗脱结合的 Hg(II)。这种新型结合相在累积 Hg(II)质量与部署时间之间表现出强烈的线性相关性，这与 DGT 原理一致。总之，当将这种新型吸附剂整合到 DGT 设计中时，它具有改善天然水中 Hg 监测的巨大潜力。
