Instituto Nacional del Carbón (CSIC), C/Francisco Pintado Fe, N° 26, 33011 Oviedo, Spain.
Instituto Nacional del Carbón (CSIC), C/Francisco Pintado Fe, N° 26, 33011 Oviedo, Spain.
Chemosphere. 2015 Jan;119:459-465. doi: 10.1016/j.chemosphere.2014.07.010. Epub 2014 Aug 8.
The speciation of mercury is currently attracting widespread interest because the emission, transport, deposition and behaviour of toxic mercury species depend on its chemical form. The identification of these species in low concentrations is no easy task and it is even more complex in coal combustion products due to the fact that these products contain organic and mineral matter that give rise to broad peaks and make it difficult to carry out qualitative and quantitative analysis. In this work, a solution to this problem is proposed using a method based on thermal desorption. A sequential extraction procedure was employed for the comparison and validation of the method developed. Samples of fly ashes and soils were analyzed by both of these methods, and thermal desorption was found to be an appropriate technique for mercury speciation. Even in the case of low mercury contents, recovery percentages were close to 100%. The main mercury species identified in the samples studied were HgS and, to a lesser extent, HgO and HgSO4. In addition, although the presence of mercury complexes cannot be demonstrated, the desorption behaviour and sequential extraction results suggest that this element might be associated with the mineral matrix or with carbon particles in some of the solids.
汞的形态目前引起了广泛的关注，因为有毒汞形态的排放、传输、沉积和行为取决于其化学形态。在低浓度下识别这些形态并非易事，在煤燃烧产物中更为复杂，因为这些产物含有有机和矿物质，会导致宽峰，难以进行定性和定量分析。在这项工作中，提出了一种使用基于热解吸的方法来解决这个问题。采用顺序提取程序对所开发方法进行了比较和验证。通过这两种方法分析了飞灰和土壤样品，结果表明热解吸是一种用于汞形态分析的合适技术。即使在汞含量较低的情况下，回收率也接近 100%。在所研究的样品中鉴定出的主要汞形态是 HgS，其次是 HgO 和 HgSO4。此外，尽管不能证明汞配合物的存在，但解吸行为和顺序提取结果表明，该元素可能与某些固体中的矿物质基质或碳颗粒有关。
