RETENTION IN RP-HPLC - LIPOPHILICITY DETERMINATION OF SUBSTITUTED BIPHENYLS BY REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

The RP-HPLC capacity factors (k') of a series of substituted biphenyls were determined on a C-18 column with methanol/water as the mobile ph ase. A linear relationship was found between log k' and the volume fra ction of methanal (phi) for each of the 25 tested compounds with the c orrelation coefficient > 0.99. High correlation was found between log k'(W) and S, which are intercept and slope of plot of log k' vs. phi, respectively. The values of S and log k'(W) were quantitatively correl ated with the solvatochromic parameters of the solutes and two statist ically significant equations were established which showed that solute volume and hydrogen bond basicity were of major importance in influen cing the retention of these studied compounds. The obtained log k'(W) was chosen as a measure of the solute hydrophobicity and will be used for the on-going Quantitative Structure-Activity Relationship (QSAR) s tudies of the substituted biphenyls.