Uncertainty contributions to species specific isotope dilution analysis.: Part 1.: Characterisation and stability of 199Hg and 13C isotopically enriched methylmercury by 1H NMR

Hg-199-enriched methylmercurychloride has been synthesised, purified, and characterised by 1 H nuclear magnetic resonance spectroscopy (NMR) for use in species specific isotope dilution analysis (IDA). The stability of methylmercury during the analytical procedure was investigated using Hg-199 and C-13 isotopically labelled methylmercury analogues and H-1 NMR spectroscopy. The halide order of preference for methylmercury was found to be I > Br > Cl. No evidence was found for the decomposition, or formation of methylmercury during equilibration with soil (NIST 2710) or dogfish muscle (DORM-2), or during the chromatographic separations.