Characterisation of reversed-phase liquid chromatography stationary phasesfor the analysis of basic pharmaceuticals: eluent properties and comparison of empirical test methods

The reversed-phase liquid chromatographic analysis of basic pharmaceuticals can be problematic. Both the properties of the eluent and the stationary p hase can influence the chromatographic performance. Therefore selection of suitable experimental conditions for the analysis of basic compounds can be difficult. This paper shows that the organic modifier and the nature of th e buffer influence the eluent properties. Moreover, the nature and amount o f modifier also influence the basicity of the analytes. Investigations show ed that the nature of the buffer can have a significant influence on retent ion and peak shape of basic compounds. Test procedures using basic analytes as test probes provided relevant information with respect to selecting col umns to analyse basic pharmaceutical compounds. Test procedures using compo unds like aniline, phenol and benzene were found to be less suitable. (C) 2 001 Published by Elsevier Science B.V.