A newly developed computerized expert system can predict starting mobi
le-phasecompositions based on the chemical structure of the solutes wi
thout performing experiments. The system calculates 1-0ctanol-water pa
rtition coefficients and recognizes the ionizable groups. The calculat
ion enables the use of reversed-phase and ion-pair chromatography meth
ods. Application of the system's suggested initial mobile phase ensure
s that solute peaks will be in a predefined capacity factor range. Sub
sequent optimization steps usually allow reasonable separations to be
achieved in two to four chromatographic runs.