Terpenoids: LXIV evaluation of polyesters as stationary phases in gas-liquid chromatography of terpenoids

Abstract

Polyesters from different 1,ω-dicarboxylic acids HOOC·(CH₂)_n · COOH ranging from malonic acid (n = 1) to hexadecane-1,16-dicarboxylic acid (n = 16) with diethylene glycol were prepared and evaluated as substrates for gas-liquid chromatography. Several terpenic and non-terpenic compounds were analysed. It was observed that the number of methylene groups in the acid fragment of the polyester has a profound influence on the retention time, on the basis of which an interesting mathematical relationship has been developed. The retention time appears to be a characteristic of the number of methylene groups between the two carboxyl groups and the contribution of a single methylene group to the retention time of a particular compound at a particular temperature has been found to be a constant. This relationship holds good for aliphatic and alicyclic hydrocarbons and only slightly deviates for aromatic hydrocarbons.