Dipartimento di Scienze della Terra, Università di Firenze, Via G La Pira 4, 50121 Firenze, Italy.
Environ Sci Technol. 2013 Jun 18;47(12):6231-8. doi: 10.1021/es304953a. Epub 2013 Jun 5.
Recent studies demonstrated that synthetic calcite may host considerable amounts of arsenic (As). In this paper, the concentration of As in natural calcite was determined using two novel, specifically designed, sequential extraction procedures. In addition, the oxidation state of As and its distribution between calcite and coexisting Fe-oxyhydroxides was unravelled by μXRF elemental mapping and As K-edge μXAS spectroscopy. Our results conclusively demonstrate that arsenic can be found in natural calcite up to 2 orders of magnitude over the normal crustal As abundances. Because of the large diffusion of calcite in the environment, this phase may exert an important control on As geochemistry, mobility, and bioavailability.
最近的研究表明，合成方解石可能含有相当数量的砷（As）。在本文中，使用两种新设计的、专门设计的连续提取程序来确定天然方解石中的砷浓度。此外，通过μXRF 元素映射和 As K 边μXAS 光谱研究了砷的氧化态及其在方解石和共存的铁氢氧化物之间的分布。我们的结果明确表明，砷可以在天然方解石中发现，其含量超过正常地壳砷丰度的 2 个数量级。由于方解石在环境中的大量扩散，该相可能对砷地球化学、迁移性和生物利用性产生重要影响。
