A method is described for the fractionation of corticosteroids in mixtures by means of column chromatography with small size columns, reduced elution times and continuous monitoring of the ellluent with data recording.
As a test mixture, eight natural corticosteroids were chosen in order to reproduce extracts from glands or biological fluids: corticosterone, 1 I-dehydrocorticosterone, I 1 -deoxycortisol, cortisone, cortisol, aldosterone, tetrahydrocortisone and tetrahydrocortisol.
Firstly, the influence of the activation of the adsorbent on the separation was studied and the shape and the extent of the gradient were considered. The adsorbents weresilicic acids of different structural types, and the gradient components were methanol and chloroform.
Monitoring of the ellluent was performed by means of two detectors, acting in parallel : the first was a UV detector and the second was a hydrogen game ionization detector, part of the eflluent being continuously drawn off to the detector. Conditions for the optimization of the separations are reported and possible analytical applications are discussed.