METHOD DEVELOPMENT BY AN EXPERT-SYSTEM - ADVANTAGES AND LIMITATIONS

Several approaches can be used for the prediction of the optimum eluen t composition in RP-HPLC, but only a few are known that use the struct ure of the solute. The latest release of the computer program EluEx, v ersion 3.0, was developed to help the chromatographer in practical wor k. The program is based on the prediction of the pK(2) and log P (loga rithm of 1-octanol-water partition coefficient) values of the solutes. The first eluent suggestion can be done without any preliminary pract ical work, based on the structural formulae of the solutes. In our exp erience, two or three experiments are usually sufficient to determine the optimized binary conditions. The surface heterogeneity and the div ersity of RP columns, such as the effect of silanol interaction, can b e handled by the program only to a limited extent. If the difference i n hydrophobicity between two compounds is small, the elution order can not be predicted properly in all instances. The same is true for some isomers, e.g., diastereomers. In this paper, the results of applying t he program to some neutral, acidic and basic solutes are summarized.