TOWARDS AN EXPERT-SYSTEM IN ION-EXCLUSION CHROMATOGRAPHY BY MEANS OF MULTIPLE CLASSIFICATION RIPPLE-DOWN RULES

We describe the development and maintenance of an expert system to adv ise on the configuration of systems for ion-exclusion chromatography. The aim of the system is to define appropriate conditions for the sepa ration of desired groups of acids or bases. The system is implemented in a rule-based system, multiple classification ripple-down rules, whi ch offers multiple conclusions from rules based on the attributes of t he system. In this case the attributes include physical and chemical p roperties of the solutes and the availability of instrumentation and a ccessories. With this information the method conditions can be defined for the detector, mobile-phase, whether suppression is to be used, an d other ion-exclusion chromatography method conditions. A unique featu re is that some conditions may be filled in by the program or be given by the user. Because of the nature of the ''ripple-down rules'' appro ach, in which new knowledge is always added as an amendment to an exis ting conclusion (and therefore cannot interfere with other conclusions ), the expert or user can maintain and alter the system easily accordi ng to their own needs without the help of a software engineer. The sys tem was developed and tested using cases from published papers on ion exclusion chromatography. Fur a set of 83 cases, although the expert s ystem only agreed with the published conditions in 53% of cases, when the predictions were assessed by a recognized ion chromatography exper t, 88% were pronounced ''workable''. (C) 1998 Published by Elsevier Sc ience B.V.