Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail, Laboratoire de Sécurité des Aliments de Maisons-Alfort, ANSES, Maisons-Alfort, France.
Anal Bioanal Chem. 2011 Nov;401(9):2699-711. doi: 10.1007/s00216-011-5040-1. Epub 2011 May 1.
Methylmercury (MeHg) and total mercury (THg) in seafood were determined using species-specific isotope dilution analysis and gas chromatography combined with inductively coupled plasma mass spectrometry. Sample preparation methods (extraction and derivation step) were evaluated on certified reference materials using isotopically enriched Hg species. Solid-liquid extraction, derivation by propylation and automated agitation gave excellent accuracy and precision results. Satisfactory figures of merit for the selected method were obtained in terms of limit of quantification (1.2 μg Hg kg(-1) for MeHg and 1.4 μg Hg kg(-1) for THg), repeatability (1.3-1.7%), intermediate precision reproducibility (1.5% for MeHg and 2.2% for THg) and trueness (bias error less than 7%). By means of a recent strategy based on accuracy profiles (β-expectation tolerance intervals), the selected method was successfully validated in the range of approximately 0.15-5.1 mg kg(-1) for MeHg and 0.27-5.2 mg kg(-1) for THg. Probability β was set to 95% and the acceptability limits to ±15%. The method was then applied to 62 seafood samples representative of consumption in the French population. The MeHg concentrations were generally low (1.9-588 μg kg(-1)), and the percentage of MeHg varied from 28% to 98% in shellfish and from 84% to 97% in fish. For all real samples tested, methylation and demethylation reactions were not significant, except in one oyster sample. The method presented here could be used for monitoring food contamination by MeHg and inorganic Hg in the future to more accurately assess human exposure.
采用同位素稀释分析和气相色谱-电感耦合等离子体质谱联用技术，对海产品中的甲基汞（MeHg）和总汞（THg）进行了测定。使用同位素富集的汞物种对标准参考物质评估了样品制备方法（提取和衍生步骤）。固液萃取、丙基衍生和自动搅拌可获得优异的准确度和精密度结果。在所选择的方法中，在定量限（MeHg 为 1.2μgHgkg-1，THg 为 1.4μgHgkg-1）、重复性（1.3-1.7%）、中间精密度重现性（MeHg 为 1.5%，THg 为 2.2%）和真实性（偏差误差小于 7%）方面，均获得了令人满意的指标。通过最近基于准确度分布（β-期望容忍区间）的策略，在所选择的方法的大约 0.15-5.1mgkg-1（MeHg）和 0.27-5.2mgkg-1（THg）范围内，成功地对该方法进行了验证。置信概率β设定为 95%，可接受限为±15%。然后，该方法应用于 62 个具有代表性的法国人群消费的海产品样本。MeHg 浓度通常较低（1.9-588μgkg-1），贝类中 MeHg 的百分比范围为 28%-98%，鱼类中 MeHg 的百分比范围为 84%-97%。对于所有测试的实际样本，甲基化和脱甲基反应均不显著，除了一个牡蛎样本。该方法将来可用于监测食品中 MeHg 和无机 Hg 的污染，以更准确地评估人体暴露。
