Carbon Stable Isotope Analysis of Methylmercury Toxin in Biological Materials by Gas Chromatography Isotope Ratio Mass Spectrometry

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• 作者：Jeremy Masbou ; David Point ; Ga毛l Guillou ; Jeroen E. Sonke ; Benoit Lebreton ; Pierre Richard
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：December 1, 2015
• 年：2015
• 卷：87
• 期：23
• 页码：11732-11738
• 全文大小：385K
• ISSN：1520-6882

文摘

A critical component of the biogeochemical cycle of mercury (Hg) is the transformation of inorganic Hg to neurotoxic monomethylmercury (CH₃Hg). Humans are exposed to CH₃Hg by consuming marine fish, yet the origin of CH₃Hg in fish is a topic of debate. The carbon stable isotopic composition (未¹³C) embedded in the methyl group of CH₃Hg remains unexplored. This new isotopic information at the molecular level is thought to represent a new proxy to trace the carbon source at the origin of CH₃Hg. Here, we present a compound-specific stable isotope analysis (CSIA) technique for the determination of the 未¹³C value of CH₃Hg in biological samples by gas chromatography combustion isotope ratio mass spectrometry analysis (GC-C-IRMS). The method consists first of calibrating a CH₃Hg standard solution for 未¹³C CSIA. This was achieved by comparing three independent approaches consisting of the derivatization and halogenation of the CH₃Hg standard solution. The determination of 未¹³C_CH3Hg values on natural biological samples was performed by combining a CH₃Hg selective extraction, purification, and halogenation followed by GC-C-IRMS analysis. Reference 未¹³C values were established for a tuna fish certified material (ERM-CE464) originating from the Adriatic Sea (未¹³C_CH3Hg = 鈭?2.1 卤 1.5鈥? 卤 2 SD). This value is similar to the 未¹³C value of marine algal-derived particulate organic carbon (未¹³CPOC = 鈭?1鈥?.