The use of gas chromatography has been established as a useful and productive tool with which to study complex organic substances. The analysis of an oil begins with the identification of the triglycerides present. The triglycerides must first be converted into lower boilings and hence more easily separable methyl esters. A method has been developed that allows the methyl ester preparation to be carried out rapidly and effectively at room temperature. This method is then used to prepare different drying oils for gas chromatographic analysis, and hence identify drying oils and study the alteration of oils with age.