Comparative study for the retention of some benzodiazepines in reversed-phase liquid chromatography using C8, C18, C6H5 and CN stationary phases

Abstract

The retention behavior of six benzodiazepines (alprazolam, bromazepam, diazepam, flunitrazepam, medazepam, and nitrazepam) was studied using four different stationary phases, under reversed-phase mechanism in high-performance liquid chromatography. Four stationary phases were used for evaluating the retention of these compounds at fixed temperature. Functional dependences of the retention factor on the content of the organic modifier (methanol, or acetonitrile) in the composition of mobile phase were calculated. The extrapolated values of the retention factor for zero content of the organic modifier in mobile phase were higher for acetonitrile than for methanol for all studied compounds and for the four types of stationary phases.