The objective of the work presented here was to develop a method of selectively analyzing for dialkylmercury compounds at the nanogram level without it being necessary to convert these compounds to their chloride salts for electron capture detection. An homologous series of four dialkylmercury compounds beginning with dimethylmercury was successfully separated using a 6 ft × 2 mm, i.d., glass column packed with 5% DC-200 + 3% QFI (copacked) on Gas Chrom Q (80/100 mesh). The separation was accomplished by programming the column oven temperature from 70°C, after a two minute hold, to 180°C at a rate of 20°C/min. The separated compounds were combusted in an FID and the resultant free mercury was passed into a cold vapor mercury detector. Practical absolute sensitivity for mercury was 0.1 ng using a Colman Mercury Analyzer MAS-50. This combined separation and detection technique provides a unique, specific and highly sensitive method of direct identification of dialkylmercury compounds.