Collaborative study on determination of mono methylmercury in seafood

Abstract

Eight laboratories participated in an inter-laboratory method-performance (collaborative) study of a method for the determination of mono methylmercury (MMHg) in foodstuffs of marine origin by gas chromatography inductively coupled plasma isotope dilution mass spectrometry (GC-ICP-IDMS) after dissolution, derivatisation and extraction of the species. The method was tested on seven seafood products covering both a wide concentration range and variations in the MMHg concentrations as well as matrix compositions. The samples were mussel tissue, squid muscle, crab claw meat, whale meat, cod muscle, Greenland halibut muscle and dogfish liver (NRCC DOLT-4), with MMHg concentrations ranging from 0.035 to 3.58mg/kg (as Hg) dry weight. Repeatability relative standard deviations (RSDr) for MMHg ranged from 2.1% to 8.7%. Reproducibility relative standard deviations (RSDR) ranged from 5.8% to 42%. All samples showed HorRat value below 1.0, except for the sample with the lowest MMHg content, mussel tissue, with a HorRat value of 1.6.

Keywords: Acetic acid (PubChem CID: 176); Argon (PubChem CID: 23968); Codex; Collaborative study; Helium (PubChem CID: 23987); Hexane (PubChem CID: 8058); Inter-laboratory method performance; Maximum limit; Mercury; Methylmercury (PubChem CID: 6860); Mono methylmercury; Nitric acid (PubChem CID: 944); Seafood safety; Sodium acetate (PubChem CID: 517045); Sodium hydroxide (PubChem CID: 14798); Sodium tetraethylborate (PubChem CID: 23681030); Standard method; Tetramethylammonium hydroxide (PubChem CID: 60966).