Gas-liquid chromatographic analyses: VII. Gas chromatography of C1—C8n-alkyl acetates and methyl esters of aliphatic C2—C9n-carboxylic acids and certain of their monochlorinated derivatives on carbowax 20M and SE-30 glass capillary columns

Abstract

The gas chromatography of mixtures of n-alkyl acetates (CH3COOR, R = C1—C8) and methyl esters of aliphatic n-carboxylic acids (R′COOCH3, R′ = C1—C8) and certain of their monochlorinated derivatives has been studied on Carbowax 20M and SE-30 glass capillary columns under the same operating conditions. The separation of the isomeric monochlorinated esters was complete on Carbowax 20M, whereas on SE-30 the peaks of 6- and 7-chlorooctyl acetates and methyl (ω − 1)- and (ω − 2)-chlorooctanoates and -nonanoates partly overlapped. The complete separation of the mixtures could not be achieved, however, on Carbowax 20M, in spite of the use of various operating conditions. The results show that all 44 individual components can be separated using columns with polar and non-polar stationary phases. The relative retention times for the compounds are given and the elution order is discussed. The retention times of alkyl acetates are always shorter that those of methyl esters with the same chain lengths (RR′). The greatest disparities are observed between the retention behaviours of 1-chloroalkyl acetates and methyl 2-chloro esters, whereas the effect fo a chlorine substituent further away seems to be negligible.