title: Acetic acid improves the sensitivity of theophylline analysis by gas chromatography-mass spectrometry.
abstract: In the analysis of theophylline by gas chromatography-mass spectrometry (GC-MS), we found that the addition of acetic acid to the solvent (ethyl acetate) decreased the adsorption of theophylline to the glass wool packed into the inlet liner. The addition of acetic acid to ethyl acetate improved the sensitivity for theophylline (optimum concentration of 3%). This simple and sensitive method without derivatization can be applied to the quantification of theophylline in serum samples in clinical and toxicological practice.
authors.affiliation: Department of Forensic Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. kanju@m.u-tokyo.ac.jp
authors.forename: Kanju
authors.initials: K
authors.lastname: Saka
authors.forename: Koichi
authors.initials: K
authors.lastname: Uemura
authors.forename: Kaori
authors.initials: K
authors.lastname: Shintani-Ishida
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D001993:Bronchodilator Agents / Q000097:blood*; D002138:Calibration; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013806:Theophylline / Q000097:blood*
chemical_list: D001993:Bronchodilator Agents; D013806:Theophylline; D019342:Acetic Acid