Analysis of pyridine, 2-picoline, piperidine, and 2-pipecoline by gas chromatography was examined. Specific retention volume of each base to pyridine was measured in each column of triethanolamine, diethanolamine, Silicone 550, and liquid paraffin. It was found that one of the columns by itself could not separate the foregoing four bases. Approximately complete separation of these four kinds of bases was effected by connection of 3-m. column of triethanolamine or diethanolamine and 1.5-m. column of Silicone 550 in series, with the column temperature of 120°. In accordance with the proposal of Jones and Kieselbach, relative peak separation, relative peak sharpness, and resolution of this combined column were calculated.