The effects of pH and ionic strength of the mobile phase, as well as the concentration of organic modifiers, on the retention and elution order of zwitterionic and neutral compounds related to imidazolinone herbicides was studied by using polymeric alkylamide stationary phases. It is shown that retention of these compounds on alkylamide phases is governed by a mixed ionexchange and partition-displacement mechanism. After adjusting pH, ionic strength and composition of the eluent, these phases allow a simultaneous separation of nonpolar and ionic compounds.