title: Determination of theophylline and its metabolites by liquid chromatography.
abstract: A high pressure liquid chromatographic assay has been developed for the separation and quantitation of theophylline and its metabolites (1-methyl uric acid, 3-methyl xanthine, and 1,3-dimethyl uric acid), theobromine, and dyphylline in biological fluids, viz. human serum, urine, and saliva. The serum has been rendered protein-free by passage through a filter with a nominal molecular weight limit of 10,000. The filtrate is injected onto a reverse-phase column and the separation achieved by utilizing a polar mobile phase and dyphylline (dihydroxypropyl theophylline) as the internal standard. The results for two normal subjects are included to illustrate the applicability of the technique.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D012463:Saliva / Q000032:analysis; D013805:Theobromine / Q000032:analysis; D013806:Theophylline / Q000031:analogs & derivatives / Q000032:analysis* / Q000097:blood / Q000378:metabolism / Q000652:urine; D014527:Uric Acid / Q000031:analogs & derivatives / Q000032:analysis; D014970:Xanthines / Q000032:analysis
chemical_list: D014970:Xanthines; D014527:Uric Acid; D013806:Theophylline; D013805:Theobromine