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 spectromettry. 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 metabolisme studies. The major excretion products of dexamethasone were identified as isomeric 6-hydroxy metabolites. Dexamethasone as such and its 20-hydroxy metabolite were found in minor quantities. Unlike dexamethasone, triamcinolone excretes mainly unchanged from the human body. Two metabolites were identified as ll-keto- and 4.5-dihydro-triamcinolone. With the gas chromatographic methods developed. the abuse of these drugs can be detected up to 30 hours after administration of a single dose.