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 .
C0039771
theophylline
C0013360
dyphylline