Mercury species transformations during sample pre-treatment of biological tissues studied by HPLC-ICP-MS
2002 (English)In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 17, no 11, 1486-1491 p.Article in journal (Refereed) Published
A high-performance liquid chromatography (HPLC) system with a C18 column and an aqueous phase eluent (0.08% ammonium acetate and 0.02% L-cysteine) was directly connected to an inductively coupled plasma mass spectrometer (ICP-MS). HPLC-ICP-MS was used to study the abiotic formation of methylmercury, CH3Hg+, from inorganic mercury, Hg2+, as well as demethylation of CH3Hg+ to Hg2+ in biological tissues during treatment with tetramethylammonium hydroxide (TMAH) followed by pH adjustment with citric or acetic acid. Enriched isotope standards from CH3198Hg+ and 201Hg2+ were added to the samples to monitor species transformation and to apply species-specific isotope dilution (SSID) calibration. Depending on the type of sample matrix, up to 11.5% of added Hg2+ was methylated and up to 6.26% CH3Hg+ was demethylated to Hg2+. Methylation of Hg2+ probably takes place mainly during and after pH adjustment and it decreases after prolonged TMAH treatment. To minimize abiotic methylation, it is therefore recommended to proceed with pH adjustment after samples have been treated with TMAH for 24 h. There is no significant difference in the degree of methylation using citric or acetic acid.
Place, publisher, year, edition, pages
RSC Publishing, 2002. Vol. 17, no 11, 1486-1491 p.
IdentifiersURN: urn:nbn:se:umu:diva-2294DOI: 10.1039/B205246FOAI: oai:DiVA.org:umu-2294DiVA: diva2:140229