Carbon Stable Isotope Analysis of Methylmercury Toxin in Biological Materials by Gas Chromatography Isotope Ratio Mass Spectrometry
- 10 November 2015
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 87 (23), 11732-11738
- https://doi.org/10.1021/acs.analchem.5b02918
Abstract
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 (δ(13)C) 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 δ(13)C 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 δ(13)C CSIA. This was achieved by comparing three independent approaches consisting of the derivatization and halogenation of the CH3Hg standard solution. The determination of δ(13)C(CH3Hg) values on natural biological samples was performed by combining a CH3Hg selective extraction, purification, and halogenation followed by GC-C-IRMS analysis. Reference δ(13)C values were established for a tuna fish certified material (ERM-CE464) originating from the Adriatic Sea (δ(13)C(CH3Hg) = -22.1 ± 1.5‰, ± 2 SD). This value is similar to the δ(13)C value of marine algal-derived particulate organic carbon (δ(13)CPOC = -21‰).Keywords
Funding Information
- Ministère de l'Enseignement Supérieur et de la Recherche (ED SDU2E/UPS)
- Observatoire Midi-Pyrénées
- Centre National de la Recherche Scientifique
This publication has 39 references indexed in Scilit:
- Tracing Carbon Sources through Aquatic and Terrestrial Food Webs Using Amino Acid Stable Isotope FingerprintingPLOS ONE, 2013
- Methylmercury photodegradation influenced by sea-ice cover in Arctic marine ecosystemsNature Geoscience, 2011
- Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and modelsGlobal Biogeochemical Cycles, 2009
- Simultaneous Determination of Species-Specific Isotopic Composition of Hg by Gas Chromatography Coupled to Multicollector ICPMSAnalytical Chemistry, 2008
- Human impacts on open ocean mercury concentrationsGlobal Biogeochemical Cycles, 2007
- Measurements of dissolved methylmercury in natural waters using diffusive gradients in thin film (DGT)Journal of Environmental Monitoring, 2006
- Stable isotope analysis of fatty acids by gas chromatography–isotope ratio mass spectrometryAnalytica Chimica Acta, 2002
- Bioaccumulation of mercury and methylmercuryWater, Air, & Soil Pollution, 1995
- Carbon isotopic analysis of atmospheric methane by isotope‐ratio‐monitoring gas chromatography‐mass spectrometryPublished by American Geophysical Union (AGU) ,1995
- Determination of volatile mercury species at the picogram level by low-temperature gas chromatography with cold-vapour atomic fluorescence detectionAnalytica Chimica Acta, 1988