Development of a standardized analysis strategy for basic drugs, using ion-pair extraction and high-performance liquid chromatography - II. Selection of preferred HPLC-systems.

A test set of 100 basic drugs has been chromatographed on 16 preselected HPLC-systems using four different types of stationary phase (Si-, NH2-, CN- and C18-). A numerical treatment of the chromatographic data, based on the discriminating power concept, results in the selection of two preferred HPLC systems for basic drugs. both using the CN-bonded phase. The preferred eluents are n-heptane-dichloromethane-acetonitrile-propylamine (25:50:25:0.1) and acetonitrile-water-propylamine (90:10: 0.01). The two preferred HPLC systems are adopted in a standardized analysis strategy.