The analysis of inorganic and methyl mercury by derivatisation methods; opportunities and difficulties

We discuss three methods of analysis of methyl and inorganic mercury in sediments and water and present new results for one of these. The methods used are (1) solvent extraction and derivatization to CH3HgBr (with separate analysis of inorganic mercury) with determination by electron capture gas chromatography, (2) aqueous phase derivatization using NaB(C2H5)4 with detection by atomic absorption spectroscopy and (3) derivatization with NaBH4 with detection of CH3Hg and inorganic mercury by atomic absorption and mass spectroscopes. We present new results on the analytical stability of CH3HgH and discuss errors arising in the methods.