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

Abstract

The reversed-phase liquid chromatographic (RPLC) retention of substituted benzanllides and benzamides was studied to determine hydrophobic substituent contributions to retention. Multiple linear regression analysis was used to evaluate functional group retention increments, τ, of aromatic substituents (CI, CH 3 , OCH 3 , and NO 2 ) on octadecyl-bonded sillica stationary phases as the molecular environment of the substituent and organic modifier conentration of the mobile phase were varied. The data illustrate the sensitivity of RPLC toward descrimination among subtile variations in molecular environment.