Environmental Chemistry Department, Institute of Environmental Assessment and Water Research, IDÆA-CSIC, Barcelona, Spain.
Chemosphere. 2011 Nov;85(9):1452-7. doi: 10.1016/j.chemosphere.2011.07.080. Epub 2011 Sep 16.
The Diffusive Gradients in Thin films (DGT) technique is an operationally defined method to determine the dissolved fraction of trace elements in water. The aim of this study was to develop this technique for the measurement of the bioavailable mercury species in natural waters. For that purpose, three types of DGT units (commercial, manufactured with agarose diffusive gel (DG) and manufactured with polyacrylamide DG) were tested under controlled conditions using an Hg(II) solution both with and without dissolved organic matter (DOM). An acid digestion method using aqua regia was optimised to efficiently digest the resin gel discs prior to analysis. A good performance was obtained for the three DGT types when deployed in a DOM-free mercury solution in the laboratory, and it was demonstrated that polyacrylamide gel can be used as diffusive layer for mercury sampling. However, when the DGT units were deployed in a mercury solution containing DOM, performance differences were observed. Furthermore, the mass of background mercury (blanks) varied among the different DGT types. In the light of the results, the devices manufactured with polyacrylamide DG seemed to be the best choice for dissolved mercury determination.
薄膜扩散梯度（DGT）技术是一种操作定义的方法，用于确定水中痕量元素的溶解部分。本研究的目的是开发该技术，用于测量天然水中生物有效态汞的形态。为此，使用含有和不含有溶解有机物（DOM）的 Hg(II) 溶液，在受控条件下测试了三种类型的 DGT 装置（商业、用琼脂糖扩散凝胶（DG）制造和用聚丙烯酰胺 DG 制造）。使用王水优化了一种酸消解方法，以便在分析之前有效地消解树脂凝胶盘。当在实验室中在无 DOM 的汞溶液中部署时，三种 DGT 类型都表现出良好的性能，并且证明聚丙烯酰胺凝胶可用作汞采样的扩散层。然而，当 DGT 装置部署在含有 DOM 的汞溶液中时，观察到性能差异。此外，不同 DGT 类型之间的背景汞（空白）质量有所不同。根据结果，用聚丙烯酰胺 DG 制造的装置似乎是测定溶解汞的最佳选择。
