Queipo-Abad S. auteur aut IRD Lagane Christelle auteur aut IRD Point David auteur aut IRD text journalArticle eng text/pdf born digital access Despite several decades of mercury research, answering fundamental questions on where and how methylmercury (CH3Hg) toxin is naturally produced in aquatic ecosystems, is still highly challenging. Investigating complex and/or coupled processes in the context of global changes requires new high-resolution analytical tools. The purpose of the compound specific carbon stable isotopic analysis (delta C-13-CSIA) of the methyl group of methylmercury (CH3Hg), is to explore how the carbon cycle contributes to CH3Hg sources and formation pathways. The main problem associated with recent CH3Hg delta C-13-CSIA methods is the limited sensitivity when using Liquid Injection (LI)-GC-C-IRMS techniques, requiring several micrograms of CH3Hg (as Hg). In this work, we present the development and application of an original Purge-&-Trap system (PT) coupled to a GC-C-IRMS with the purpose of transferring and analyzing the total amount of CH3Hg available in a sample vial in the low nanogram range. The new PT-GC-C-IRMS system enhance the sensitivity by a factor better than 200, relative to LI-GC-C-IRMS, by minimizing the sample mass requirements. The delta C-13(CH3Hg) values obtained, following the same sample derivatization approach coupled to PT-GC-C-IRMS (-53.5 +/- 1.9 %), were in good agreement with the ones obtained in a previous study (-53.8 +/- 1.1 %). The standard solution was prepared from the same salt, requesting only 25-200 ng of CH3Hg (as Hg). This new methodology represents a milestone towards the analysis of large array of biological samples displaying CH3Hg concentrations in the low-mid ng g(-1) range, in order to explore the meaning of the carbon stable isotopic signature of CH3Hg in the environment. specialized Methylmercury Carbon isotopes Purge and trap Isotope ratio mass spectrometry 020 1617 art. 460821 [8p.] 2020 0021-9673 https://www.documentation.ird.fr/hor/fdi:010078979 10.1016/j.chroma.2019.460821 0021-9673 [F B010078979] https://www.documentation.ird.fr/hor/fdi:010078979 https://www.documentation.ird.fr/intranet/publi/2020/05/010078979.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2020-06-09 2025-02-24 fdi:010078979 fre