Determination of organomercurials in air by gas chromatography-atomic absorption spectrometry

Abstract

A method for the determination of nanogram amounts of dimethyl- and diethylmercury and methyl- and ethylmercury chloride in air has been developed by using gas chromatography interfaced with atomic absorption spectrometry. The mercury species were separated using dual columns connected in parallel. After separation the compounds were cracked in a furnace and the resulting free mercury was passed through the optical cell of an atomic absorption instrument tuned to the mercury resonance line at 253.7 nm. Parameters including the type of column packings, the temperature of the pyrolyser and the optimum gas flow-rate were studied. The detection limits are 0.2 ng of mercury for dimethylmercury and diethylmercury and 0.5 ng of mercury for methylmercury chloride and ethylmercury chloride. Analytical results for air sampled from different sources are presented.