Selective organomercury determination by ICP-MS made easy

Davide Spanu; Laura Butti; Ginevra Boldrocchi; Roberta Bettinetti; Sandro Recchia; Damiano Monticelli

doi:10.1016/j.aca.2022.339553

Selective organomercury determination by ICP-MS made easy

Anal Chim Acta. 2022 May 8:1206:339553. doi: 10.1016/j.aca.2022.339553. Epub 2022 Jan 26.

Authors

Davide Spanu¹, Laura Butti², Ginevra Boldrocchi³, Roberta Bettinetti³, Sandro Recchia⁴, Damiano Monticelli⁵

Affiliations

¹ Department of Science and High Technology, University of Insubria, Via Valleggio 11, Como, Italy. Electronic address: davide.spanu@uninsubria.it.
² Department of Science and High Technology, University of Insubria, Via Valleggio 11, Como, Italy.
³ Department of Human Sciences, Innovation and Territory, University of Insubria, Via Valleggio 11, Como, Italy.
⁴ Department of Science and High Technology, University of Insubria, Via Valleggio 11, Como, Italy. Electronic address: sandro.recchia@uninsubria.it.
⁵ Department of Science and High Technology, University of Insubria, Via Valleggio 11, Como, Italy. Electronic address: damiano.monticelli@uninsubria.it.

PMID: 35473882
DOI: 10.1016/j.aca.2022.339553

Abstract

A fast and cost-effective procedure based on Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) for the selective determination of methylmercury (MeHg) is proposed and validated for fish tissue analysis. Selectivity for MeHg is achieved by simply inserting a strong anion exchange resin to block inorganic mercury as negatively charged chloride species, leaving MeHg unretained. The procedure features a 15 min extraction time followed by a 100 s analysis time achieving a limit of detection of 1.6 μg kg^-1 on solid samples. The effect of the solution composition and inorganic mercury concentration were extensively studied to fully assess the selectivity of the procedure: Hg(II):MeHg ratios up to 50 are tolerated and cause systematic errors lower than 15%. The entire procedure was successfully validated by standard reference material from the marine food web, namely fish muscle and liver plus zooplankton. The method was finally applied to the detection of MeHg in the marine trophic web of Djibouti (Gulf of Aden): a trophic magnification factor of 13.5 proved the high risk associated with the biomagnification of methylmercury.

Keywords: Fish tissues; ICP-MS; Mercury speciation; Methylmercury; On-line separation; Trace element.

MeSH terms

Animals
Fishes
Food Chain
Mercury* / analysis
Methylmercury Compounds* / analysis
Spectrum Analysis

Substances

Methylmercury Compounds
Mercury