title: Gas-chromatographic micro-scale procedure for theophylline, with use of a nitrogen-sensitive detector.
abstract: We report a micro-scale procedure for determination of theophylline by use of gas chromatography with nitrogen-sensitive detection. The procedure requires only 10 mul of serum, plasma, or saliva. This sample size makes the determination especially appropriate for monitoring in a pediatric population. With the sample volume used, background interference is equivalent to about 0.1 mg/liter and 0.5 mg of theophylline per liter can easily be measured. The new method correlates well with our earlier flame ionization gas-chromatographic procedure that required 1 ml of sample [Clin. Chem. 21, 1038 (1975)]. The selectiviey of the nitrogen detector allows a simplified extraction procedure. Between-run precision (CV) is 2.8% at a theophylline concentration of 14.8 mg/liter.
mesh_terms: D002110:Caffeine / Q000032:analysis; D002849:Chromatography, Gas / Q000379:methods; D006801:Humans; D008832:Microchemistry; D009584:Nitrogen; D010634:Phenobarbital / Q000032:analysis; D012463:Saliva / Q000032:analysis; D013805:Theobromine / Q000032:analysis; D013806:Theophylline / Q000032:analysis* / Q000097:blood / Q000652:urine; D014970:Xanthines / Q000032:analysis
chemical_list: D014970:Xanthines; D002110:Caffeine; D013806:Theophylline; D009584:Nitrogen; D013805:Theobromine; D010634:Phenobarbital