Development and validation of a new analytical approach for simultaneous speciation analysis of Hg and Se in fishery products by HPLC-ICP-MS

M. Ribeiro, E. Galli, J. A. L. Silva, I. Castanheira, A. Leufroy, P. Jitaru

Abstract

This study reports the development and validation of a new analytical method for the simultaneous speciation analysis of Se and Hg in fish muscle. For this purpose, four Se species (Se(IV), Se(VI), Se-methionine/SeMet and Se-cysteine/SeCys) and two Hg species (Hg(II) and methylmercury/MeHg) were extracted simultaneously by microwave assisted enzymatic hydrolysis (using protease XIV at pH 7 ≈ and 2-mercaptoethanol) and then separated in less than 15 min by using a mixed mechanism anion-cation exchange HPLC with a mobile phase consisting of a mixture of methanol 5% (v/v), 45 mM HNO3, 0,015% 2- mercaptoethanol and 1,5 mM sodium 3-mercapto-1-propanesulfonate. The separated species were detected online by inductively coupled plasmamass spectrometry. The speciation method was validated by means of the accuracy profile approach by carrying out 3 measurement series in duplicate on (3) different days over a time-span of 3 weeks. The quantification limits (LQ) are in the range of 0.055-0.074 µg/L for all selenium species, except for Se(IV) (85 µg=L) while the coefficient of variation in terms of intermediate reproducibility (CV_R) was <7 %. For MeHg, the LQ for was 0.037 µg/L, while the CV_R was 3%. The method was successfully applied to the analysis of muscle samples from four different fish species: rainbow trout, tuna, swordfish and dogfish.

Keywords

SeMet, Se(IV), Se(IV), SeCys, MeHg, anion-cation exchange, fish, MAEE

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IMEKO-TC23-2023-022.pdf

DOI

10.21014/tc23-2023.022

IMEKO TC

TC23 - Metrology in Food and Nutrition

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