Analysis of dexamethasone, triamcinolone, and their metabolites in human urine by microcolumn liquid and capillary gas chromatography mass spectrometry

Adult male volunteers were administered orally 10 mg of the respective drug. Urine samples were investigated by microcolumn liquid chromatography and capillary gas chromatography combined with on-line mass spectrometry. The former technique was found to be usable for the detection of these drugs. The latter method appeared to be superior in terms of sensitivity and for metabolism studies. The major excretion products of dexamethasone were identified as isometric 6-hydroxy metabolites. Dexamethasone as such and its 20-hydroxy metabolite were found in minor qualities. Unlike dexamethasone, triamcinolone is excreted largely unchanged from the human body. Two metabolites were identified as 11-keto and 4,5-dihydrotriamcinolone. With the gas chromatographymethods developed abuse of these drugscan bedetected up to 24 h after administration of a 5 mg single dose