Hg Compound-Specific Isotope Analysis at Ultratrace Levels Using an on Line Gas Chromatographic Preconcentration and Separation Strategy Coupled to Multicollector-Inductively Coupled Plasma Mass Spectrometry - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Analytical Chemistry Année : 2018

Hg Compound-Specific Isotope Analysis at Ultratrace Levels Using an on Line Gas Chromatographic Preconcentration and Separation Strategy Coupled to Multicollector-Inductively Coupled Plasma Mass Spectrometry

Résumé

Stable Hg isotope analyses are nowadays widely employed to discriminate Hg sources and understand its biogeochem. cycle. Until now, total Hg isotopic compns. were mainly used but Hg compd.-​specific isotopic anal. (CSIA) methodologies are emerging. Online Hg-​CSIA were limited to samples contg. high concns., but the authors overcome this limitation for the measurement of inorg. (IHg) and monomethylmercury (MMHg) by gas chromatog. hyphenated to multicollector-​inductively coupled plasma mass spectrometry (GC​/MC-​ICPMS) through the use of an automated online preconcn. strategy, allowing injection vols. up to 100 times larger than usual. The preconcn. of Hg species and subsequent transfer to the column were achieved by a programmed temp. vaporization (PTV) injector fitted with a packed liner. The PTV parameters were 1st optimized using a quadrupole ICPMS, and then its suitability for Hg-​CSIA was evaluated with long-​term replicate anal. of various stds. and ref. materials (root-​mean-​square)​. The large preconcn. capability enables analyses with Hg concns. in the org. solvent 2 orders of magnitude lower than the previous conventional GC​/MC-​ICPMS method, but a compd. specific std. bracketing procedure was required for MMHg to correct for the differential behavior of Hg species in the liner. The external reproducibility of the method ranged from 0.19 to 0.39 ‰ for Δ199Hg and δ202Hg (as 2 SD, n = 143-​167) depending on the species. The anal. of various root-​mean-​square demonstrated the applicability to environmental samples with species concns. down to ∼150 ng g-​1. This new methodol. opens the way for a much wider range of online Hg-​CSIA measurements that will improve the authors' understanding of the Hg biogeochem. cycle.
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hal-01982304 , version 1 (15-01-2019)

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  • HAL Id : hal-01982304 , version 1

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Sylvain Bouchet, Sylvain Bérail, David Amouroux. Hg Compound-Specific Isotope Analysis at Ultratrace Levels Using an on Line Gas Chromatographic Preconcentration and Separation Strategy Coupled to Multicollector-Inductively Coupled Plasma Mass Spectrometry. Analytical Chemistry, 2018, 90 (13), pp.7809-7816. ⟨hal-01982304⟩
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