Spectroscopy Unit, Chemistry Division, Technology Department, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Av. Complutense 40, E-28040 Madrid, Spain.
Ecotoxicol Environ Saf. 2013 Nov;97:196-203. doi: 10.1016/j.ecoenv.2013.07.013. Epub 2013 Aug 13.
The development of a sequential extraction method for mercury in solid environmental samples is presented. The scheme recognizes and quantifies four major phase associations of mercury: "Labile mercury species", "Hg bound to humic and fulvic complexes", "elemental Hg and bound to crystalline oxides" and "Hg sulfide and refractory species". Model solids were used in this study to evaluate different extracting solutions and to determine optimum extraction conditions. Sequential and single-step extractions were conducted to evaluate the interaction among the successive steps. Different variables such as extractant concentration, time, temperature and number of extractions were optimized for each stage when necessary. The selectivity of the selected extractions was assured through experiments with natural and synthetic matrices of some specific Hg-bearing phases. The suitability of the proposed method was evaluated by using four certified reference materials from different Hg sources, physicochemical properties and total Hg content (from 0.3µgg(-1) to 33µgg(-1)). Recovery of total Hg by the sum of fractions in reference materials showed that the accuracy of the method ranges from 85 percent to 105 percent.
本文提出了一种用于固体环境样品中汞的连续提取方法。该方案识别并定量了汞的四种主要形态：“活性汞形态”、“与腐殖质和富里酸络合的汞”、“元素汞和与结晶氧化物结合的汞”以及“汞的硫化物和难溶形态”。本研究采用模型固体来评估不同的提取溶液，并确定最佳的提取条件。连续和单步提取用于评估连续步骤之间的相互作用。必要时，针对每个阶段优化了提取剂浓度、时间、温度和提取次数等不同变量。通过对一些特定含汞相的天然和合成基质进行实验，保证了所选提取方法的选择性。通过对来自不同汞源、物理化学性质和总汞含量（从 0.3µgg(-1)到 33µgg(-1)）的四种认证参考物质进行评估，验证了该方法的适用性。参考物质中各部分总和的总汞回收率表明，该方法的准确度在 85%至 105%之间。
