International Atomic Energy Agency, Environment Laboratories, 4 Quai Antoine 1(er), MC, 98000, Monaco.
International Atomic Energy Agency, Environment Laboratories, 4 Quai Antoine 1(er), MC, 98000, Monaco.
Talanta. 2021 Sep 1;232:122492. doi: 10.1016/j.talanta.2021.122492. Epub 2021 May 4.
Among ionic mercury species methyl mercury (MMHg) is the most toxic form present in the environment, which is known to be bio-accumulative neurotoxin in the aquatic food chain and could provide the major route of exposure for humans to mercury through consumption of marine food products. The availability of reliable analytical methods for evaluating spatial and temporal contamination trends of MMHg in the ocean is an important prerequisite for marine monitoring. Sound strategies for marine monitoring call also for measurement systems capable of producing comparable analytical results with demonstrated quality. A sensitive analytical procedure for environmental monitoring of MMHg content in seawater, based on specific extraction and Gas Chromatography Atomic Fluorescence Spectrometry validated according to the requirements of international guidelines and standards, ISO 17025 and Eurachem guidelines, is presented in this study. The entire measurement process was described by mathematical equations and all factors influencing the results were systematically investigated. Selectivity, working range, linearity, recovery (94 ± 4%), repeatability (3.3%-4.5%), intermediate precision (2.9%), limits of detection (0.0004 ng kgas Hg) were systematically assessed. The relative expanded uncertainties obtained were in the range from 16% to 25%, (k = 2). Modelling of the entire measurement process related obtained values for MMHg in seawater to the International System of units (Kg). The potential of this analytical procedure was tested and additionally validated via inter laboratory comparison exercise organised under the Geotraces programme. Obtained results were in excellent agreement with the assigned values. The proposed analytical procedure from the sample preparation to the measurement step combined with the high efficiency of the new generation of the automated MMHg analyzers is fit for purpose for routine monitoring studies on the dissolved MMHg in the costal and open ocean seawaters.
在离子汞物种中，甲基汞 (MMHg) 是环境中最具毒性的形式，已知它是水生食物链中的生物累积性神经毒素，并且可能是人类通过食用海洋食品产品接触汞的主要途径。评估海洋中 MMHg 空间和时间污染趋势的可靠分析方法的可用性是海洋监测的重要前提。用于海洋监测的合理策略还需要能够产生具有证明质量的可比分析结果的测量系统。本研究提出了一种基于特定提取和气相色谱原子荧光光谱法的灵敏分析程序，用于监测海水中 MMHg 含量，该方法根据国际指南和标准（ISO 17025 和 Eurachem 指南）的要求进行了验证。整个测量过程通过数学方程式进行了描述，并系统地研究了影响结果的所有因素。该方法具有选择性、工作范围、线性、回收率（94 ± 4%）、重复性（3.3%-4.5%）、中间精密度（2.9%）、检测限（0.0004 ng kgas Hg）。获得的相对扩展不确定度在 16%至 25%（k = 2）之间。通过在 Geotraces 计划下组织的实验室间比较活动对整个测量过程的建模与海水 MMHg 获得的值与国际单位制（kg）相关联。通过测试并通过 Geotraces 计划下组织的实验室间比较活动对该分析程序进行了验证，验证结果表明，该方法具有良好的准确性和重复性，可用于常规监测研究。
