Hydrophobic substituent constants derived by intracolumn bilogarithmic analysis of reversed-phase liquid chromatographic retention of 4, 4'-disubstituted benzanilides and benzamides

Multiple linear regression analysis determines the increments in reversed- phase liquid chromatographic (RPLC) retention of 75 4,4'-disubstituted benzanilides and benzamides as a function of variations in the stationary and mobile phases. The study, which illustrates the sensitivity of RPLC to slight changes in molecular environments, shows that functional group retention depends on both the stationary and mobile phases. A statistical intracolumn bilogarithmic analysis, however, yields standardized functional group substituent constants that are phase-independent.