Evaluation and optimisation of separation buffers for the determination ofcorticosteroids with micellar electrokinetic capillary chromatography (MECC)

Separation buffers for the determination of the corticosteroids cortisone, hydrocortisone, prednisone and prednisolone with micellar electrokinetic ch romatography were developed with respect to separation efficacy and the mig ration times, depending on the type and the concentration of the organic mo difier acetonitrile as well as on the addition of gamma-cyclodextrin. The b uffer containing 50 mM SDS and 16% (v/v) acetonitrile enables the rapid pro filing of prednisolone together with cortisone and prednisone. Addition of gamma-cyclodextrin alters the elution sequence, but does not further enhanc e resolution of the corticosteroids. Baseline separation at long migration times for cortisone, hydrocortisone, prednisone and prednisolone is achieve d with a buffer containing 50 mM each of SDS, dehydrocholic acid sodium sal t and glycodeoxycholic acid sodium salt. (C) 1998 Elsevier Science B.V. All rights reserved.