title: Mass spectrometric identification of methylxanthines and methyluric acids, the possible metabolites of caffeine.
mesh_terms: D002110:Caffeine / Q000032:analysis*; D002849:Chromatography, Gas; D013058:Mass Spectrometry; D008722:Methods; D008745:Methylation; D013805:Theobromine / Q000032:analysis; D013806:Theophylline / Q000032:analysis; D014527:Uric Acid / Q000032:analysis*; D014970:Xanthines / Q000032:analysis*
chemical_list: D014970:Xanthines; D014527:Uric Acid; D002110:Caffeine; D013806:Theophylline; D013805:Theobromine