Selenium, total mercury and methylmercury in sardine: Study of molar ratio and protective effect on the diet

Abstract

The purpose of this work was to evaluate the risk-benefit associated with canned sardine consumption, considering the selenium, the mercury and the methylmercury contents and the Se:Hg molar ratio and the Se-health benefit value (HBV) index. In this study, 63 canned sardine samples were purchased worldwide and for the determination of selenium and mercury species, the inductively coupled plasma optical emission spectrometry and thermal decomposition and amalgamation atomic absorption spectrometry were employed. The mean results obtained for the Brazilian samples varied between 12.6 and 65.5 μg kg⁻¹ for Hg; <3.7 and 45.4 μg kg⁻¹ for methylmercury; 310 and 1370 μg kg⁻¹ for Se. The MeHg/Hg ratio showed that the most toxic forms of Hg (MeHg) is predominant in 52 and 39% of the Brazilian samples conserved in tomato sauce and in oil, respectively. Nevertheless, the Se-HBV index and the Hg:Se and Se:Hg molar ratios indicated that the selenium content in canned sardine samples is enough to provide a protective effect on the Hg species.

Keywords:

• Canned fish
• heavy metals
• TDA AAS
• Se-HBV

Acknowledgment

The authors are grateful to CAPES (master’s scholarship of TEM Lazarini) and to CNPq for the financial support (process 442025/2014-9), for the research productivity scholarship of MA Morgano and LC de Sousa for analytical support.

Disclosure statement

No potential conflict of interest was reported by the authors.