title: Monitoring bronchodilators with direct injection.
abstract: A procedure was developed for the determination of caffeine and theophylline using a C18 column (5 microm, 250 mm x 4.6 mm) and micellar liquid chromatography using hybrid mobile phases containing sodium dodecyl sulfate (SDS) and propanol, butanol or pentanol as modifiers. Detection was performed with a variable wavelength UV-vis detector at 272 nm. After the application of an interpretative strategy for the selection of the optimimum mobile phase, caffeine and theophylline can be resolved and determined in serum samples by direct injection, using a mobile phase made up of 50 mM SDS-2.5% (v/v) propanol-10 mM KH2PO4, pH 7, with an analysis time below 5 min. Calibration was linear in the range 0.05 to 50 microg mL(-1) with r > 0.999. The statistical evaluation of the method was examined by performing intra-day (n = 6) and inter-day calibration (n = 7) and was found to be satisfactory, with highly accurate and precise results. The proposed method was suitably validated and applied to the determination of caffeine and theophylline in serum samples of patients treated with bronchodilators.
authors.affiliation: Servei d'Anàlisis Clíniques, Consorci Hospital Provincial de Castelló, Av. Dr. Clara 19, 12002 Castelló, Spain.
authors.forename: Adrià
authors.initials: A
authors.lastname: Martinavarro-Domínguez
authors.forename: Devasish
authors.initials: D
authors.lastname: Boseb
authors.forename: Abhilasha
authors.initials: A
authors.lastname: Durgbanshi
authors.forename: Mayte
authors.initials: M
authors.lastname: Gil-Agustí
authors.forename: Maria-Elisa
authors.initials: ME
authors.lastname: Capella-Peiró
authors.forename: Samuel Carda
authors.initials: SC
authors.lastname: Broch
authors.forename: Josep
authors.initials: J
authors.lastname: Esteve-Romero
mesh_terms: D001993:Bronchodilator Agents / Q000097:blood*; D002110:Caffeine / Q000097:blood*; D002138:Calibration; D002853:Chromatography, Liquid; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013806:Theophylline / Q000097:blood*
chemical_list: D001993:Bronchodilator Agents; D002110:Caffeine; D013806:Theophylline