Proficiency testing for total mercury in oyster with a metrologically traceable reference value from isotope dilution mass spectrometry: implications on laboratory practices using mercury analyzers

Abstract

Mercury is a toxic element of particular concern for the environment and human health, but its accurate analysis is challenging due to its unique physical and chemical properties. In order to enhance the quality and traceability of measurements, a proficiency testing (PT) program (MFDS-PT-101FM-2017) for mercury in oyster tissue has been conducted by the Ministry of Food and Drug Safety (MFDS) of Korea. A majority of the participating laboratories have used commercial mercury analyzers based on thermal decomposition amalgamation atomic absorption spectrometry (TDA–AAS). Good agreement between the participants’ results and the reference value (RV) was observed, where the RV is traceable to the International System of Units and verified for international equivalence. The results of this PT program support the participating laboratories in demonstrating their competence in quantitative analysis, and show the potential of commercial TDA–AAS systems for accurate mercury analysis.