Gas-liquid chromatographic analyses : XXVII. Separation of chlorinated 4-hydroxybenzaldehydes on a capillary column coated with non-polar SE-30 stationary phase

Abstract

A mixture of all nine chlorinated 4-hydroxybenzaldehydes and the parent homologue was separated on a non-polar SE-30 capillary column using various isothermal and temperature-programmed operating conditions. The relative retention data for the compounds are given and the retention indices together with the retention index increments for each position of chlorine substitution are examined. The retention order 3-Cl<parent<2,5-di-Cl<2,3-di-Cl<3,5-di-Cl<2-Cl<2,3,5-tri-Cl<2,3,6-tri-Cl<2,6-di-Cl<tetra-Cl isomer obtained indicates that the effect of the position of substitution on the retention behaviour is greater than that of the number of chlorine atoms. The retention is maximal with 2-Cl and 2,6-di-Cl isomers i.e., o-chloro and o, o′-dichloro isomers with respect to the formyl group, and minimal with the 3-Cl isomer, i.e., o-chloro isomer with respect to the hydroxy group.