AbstractAn extension of the work of James and Martin on the separation of volatile fatty acids and bases by gas—liquid partition chromatography is described. This technique has now been applied to the analysis of most types of volatile organic compounds on a milligram scale; mixtures of hydrocarbons, alcohols, ethers, esters, aldehydes and ketones have been separated on a column of kieselguhr impregnated with di‐(3: 5: 5‐trimethylhexyl) phthalate, and the components determined by a thermal‐conductivity