title: Separation and quantitation of theophylline and paraxanthine by reversed-phase liquid chromatography.
mesh_terms: D002110:Caffeine / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006801:Humans; D000644:Quaternary Ammonium Compounds; D013806:Theophylline / Q000097:blood*
chemical_list: D000644:Quaternary Ammonium Compounds; D002110:Caffeine; D013806:Theophylline; C009405:tetrabutylammonium; C021183:1,7-dimethylxanthine