REGULATION OF PEAK COMPRESSION EFFECTS FOR SUBSTITUTED BENZAMIDES IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY

The possibilities of regulating peak compression effects, i.e., of making the analyte peak coelute with the system peak, were investigated for substituted benzamides. The changes in capacity factor for the system peak relative to the retention of the analyte were studied by varying the composition of the mobile phase. The parameters useful for altering the capacity factor ratio were found to be the ionic strength of the phosphate buffer and to some extent the pH, whereas the amount of acetonitrile and the concentration of the amine modifier gave negligible effects. Variation of the amount of silanol groups on the solid phase could also be used as an efficient means for regulation of the capacity factor ratio. © 1990.