Effect of Capillary Rinsing Protocol on the Reproducibility of Separation in Capillary Electrophoresis with Indirect UV Detection

Capillary electrophoresis (ce) with indirect uv detection is an interesting analyticalmethod for the analysis of drugs and pharmaceuticals. good and reproducible capillary qualityis needed to develop robust methods and to facilitate method transfer in ceo it is widelyaccepted that preconditioning procedures are indispensable in capillary electrophoresis inorder to achieve reproducibility of migration times and peak areas.in order to explore different aspects of this technique, a set of experiments were performedusing vigabatrin as a model drug. the effects of capillary rinsing between each run wasinvestigated using basic (naoh 0.1 m) and acidic (phosphoric acid 0.1 mj-wash cycles. theresults of 10 consecutive injection of the model drug after each of the two wash cycles, revcalthat more reproducible results obtained when acid-wash cycle was performed as a capillaryconditioning protocol. the higher ph changes during basic-wash cycle and its effects on thecharacteristics of the capillary inner surface were suggested as a source of greater variationbetween consecutive runs