COMPARISON AND QUANTIFICATION OF CHROMATOGRAPHIC RETENTION MECHANISMSON 3 STATIONARY PHASES USING STRUCTURE-RETENTION RELATIONSHIPS

The mechanism of retention in HPLC using a non-polar solvent with a ve ry low content of various polar modifiers as mobile phase and three st ationary phases is studied. The results of preceding work are generali sed to the role of each polar modifier. This allows quantification of the interaction between stationary phases and polar modifier. Moreover , by the introduction of physicochemical descriptors of eluents it is possible to obtain for each stationary phase a simple equation correla ting retention of solutes to calculated descriptors of solutes and elu ents. The mechanism of retention is discussed with these new general e quations. The main qualitative result is proof of a direct link betwee n the polar modifier and polar groups of the stationary phases, This l ink plays the major role in differences of retention.