USE OF CYCLODEXTRINS FOR PREPURIFICATION OF PROGESTERONE AND TESTOSTERONE FROM HUMAN SERUM PRIOR TO DETERMINATION WITH ISOTOPE-DILUTION GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

A new application of cyclodextrins is presented, being their use for s ample purification. This new application is exemplified with a method for the determination of progesterone and testosterone in human serum based on isotope dilution gas chromatography/mass spectrometry. The wh ole procedure consists of a traditional solvent extraction with hexane for progesterone, respectively dichloromethane for testosterone, foll owed by a back-extraction of the steroids into a cyclodextrin-water so lution. After washing of the aqueous phase with hexane, the steroids a re finally extracted with toluene (progesterone) and dichloromethane ( testosterone). Different cyclodextrins and cyclodextrin derivatives in various concentrations are investigated. A solution of 150 mmol/L hyd roxypropyl beta-cyclodextrin in water is selected. The recovery of pro gesterone and testosterone is 70 and 80% respectively. The purificatio n effectiveness, accuracy, and precision of the new method are equival ent to a traditional method using gel chromatography for sample purifi cation.