CONTINUOUS-FLOW CHEMILUMINESCENCE DETERMINATION OF SOME CORTICOSTEROIDS

A continuous-flow method for the determination of cortisone, hydrocortisone, prednisolone and methylprednisolone in the range 0.100-1.00-mu-g ml-1 and of dexamethasone and betamethasone in the range 0.500-5.00-mu-g ml-1 is described. The procedure is based on the action of each corticosteroid as a sensitiser on the chemiluminescent oxidation of sulphite by cerium(IV). The analysis is automated, requires no sample pre-treatment and samples can be analysed at a rate of 40 per hour with a relative error of < 6%. The method was evaluated by carrying out recovery experiments and by analysing commercial formulations. Results agreed well with those given by an official method.