Comparison of liquid chromatographic methods for analysis of homologous alkyl esters of biphenyl-4,4′-dicarboxylic acid

Abstract

Homologous series of compounds are generated in systematic studies of liquid crystals, petroleum fractions and pharmaceutical compounds. The paper describes the separation of a series of homologous liquid crystalline alkyl esters of biphenyl-4,4,′-dicarboxylic acid by high-performance liquid chromatography. High-performance gel-permeation chromatography (HPGPC) was capable of separating compounds differing by a single carbon, and is, therefore, similar in resolving power to either normal- or reversed-phase liquid chromatography. High-performance gel-permeation chromatography has the advantage of permitting the analysis of compounds of widely differing polarity. If the resolution of GPC can be increased slightly by reducing the particle size and decreasing the pore size to maximize resolution in the range of 250–500 u, it could become a primary analytical technique in the organic synthetic laboratory.