The extraction and isolation of dexamethasone-related compounds

Radiolabeled dexamethasone (9-fluoro-16 alpha-methyl-11 beta, 17, 21-trihydroxy-1,4-pregnadiene-3,20-dione) was utilized to develop a practical and relatively expedient method of detection for dexamethasone and its major metabolite in horse urine. The effects of solvent, pH, salt saturation, and back extraction on the extraction efficiency of dexamethasone-related compounds and the presence of endogenous background were evaluated. Final isolations of dexamethasone and its major urinary metabolite were procured by successive thin-layer chromatography (TLC) in three different developing systems.