Li Ruiping, Wang Wenjie, Wang Shiliang, Lin Chunye, Wang Xiangyi, Meng Lingchuan, Yuan Xianlong
School of Geography and Tourism, Qufu Normal University Rizhao Campus Rizhao China
State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University Beijing China
RSC Adv. 2019 Nov 1;9(61):35456-35462. doi: 10.1039/c9ra07158j. eCollection 2019 Oct 31.
Two sequential extraction procedures including Tessier and Wenzel schemes have been evaluated for the study of tungsten fractionation in soil samples adjacent to the World's largest and longest-operating tungsten mines in China. The efficiency and suitability of two methods and the corresponding extraction steps for partitioning tungsten were compared. Results showed the Tessier scheme classical for cation metals was inappropriate for tungsten fractionation. Although the percentage of readily bioavailable tungsten fractions extracted by the Tessier method is comparable to the Wenzel method, the Tessier scheme still has some drawbacks for partitioning tungsten mainly arising from the lack of selectivity of some of the reagents used. The Wenzel scheme has higher extraction recovery and efficiency than the Tessier method, especially for extracting amorphous and crystalline oxyhydroxides which were mainly responsible for tungsten retention. As a final conclusion, the study indicated that the Wenzel scheme should be more suitable for tungsten fractionation, but we need to make further improvement on the Wenzel scheme by supplementing the extraction stage for the oxidisable fraction to find a reliable and easy to use method to characterize tungsten forms in all soil samples to provide valuable information for risk assessment.
在中国最大且运营时间最长的钨矿附近的土壤样品中，为研究钨的分级，对包括Tessier法和Wenzel法在内的两种连续提取程序进行了评估。比较了这两种方法及其相应的钨分配提取步骤的效率和适用性。结果表明，适用于阳离子金属的经典Tessier法不适用于钨分级。尽管Tessier法提取的易于生物利用的钨组分的百分比与Wenzel法相当，但Tessier法在钨分配方面仍存在一些缺点，主要是由于所使用的一些试剂缺乏选择性。Wenzel法比Tessier法具有更高的提取回收率和效率，特别是对于提取主要负责钨保留的无定形和结晶态羟基氧化物。作为最终结论，该研究表明Wenzel法应更适合钨分级，但我们需要通过补充可氧化组分的提取阶段对Wenzel法进行进一步改进，以找到一种可靠且易于使用的方法来表征所有土壤样品中的钨形态，为风险评估提供有价值的信息。
