title: Improved determination of serum theophylline by gas chromatography with use of a nitrogen-phosphorus detector.
abstract: We describe a method for the 7-min determination of theophylline in less than 100 muL of serum. The procedure requires no centrifugation or solvent evaporation after extraction. Butylation is done on the gas-chromatographic column by injecting the serum extract followed by a butylating mixture which contains 1-iodobutane as the alkylating agent. The method is precise, accurate, and free of interference. Results correlate well with those by ultraviolet spectrophotometry.
mesh_terms: D000818:Animals; D002849:Chromatography, Gas / Q000379:methods; D008832:Microchemistry; D009584:Nitrogen; D010758:Phosphorus; D013806:Theophylline / Q000097:blood*
chemical_list: D010758:Phosphorus; D013806:Theophylline; D009584:Nitrogen