RELATIONSHIP BETWEEN THE PHYSICOCHEMICAL PARAMETERS OF 3,5-DINITROBENZOIC ACID-ESTERS AND THEIR RETENTION BEHAVIOR ON BETA-CYCLODEXTRIN POLYMER SUPPORT

The retention of fourteen 3,5-dinitrobenzoic acid esters on thin layers prepared from a water-insoluble beta-cyclodextrin polymer was determined using water-methanol mixtures as eluents. Linear correlations were calculated between the R(M) value of the solutes and the methanol concentration in the eluent, and the relationship between the chromatographic characteristics (slope and intercept values of the above correlation) and the physicochemical parameters was elucidated by stepwise regression analysis. The R(M) value of solutes decreased or increased with increasing methanol concentration in the eluent. This anomalous retention behaviour was tentatively explained by possible ternary complex formation: cyclodextrin-solute-methanol. Stepwise regression analysis proved that the steric parameters of solutes have the highest impact on their retention on the polymer layers.