title: Improved screening method for beta-blockers in urine using solid-phase extraction and capillary gas chromatography-mass spectrometry.
abstract: An improved screening method for beta-blockers in urine is proposed, involving enzymatic hydrolysis, solid-phase extraction and capillary gas chromatography-mass spectrometry. Several extraction methods for beta-blockers, such as conventional liquid-liquid and solid-phase extraction procedures, have been evaluated for at least eight beta-blockers. Additionally, the gas chromatographic properties and mass fragmentation of the trimethylsilyl-trifluoroacetyl, trifluoroacetyl and cyclic n-butylboronate derivatives of beta-blockers have been compared and evaluated with respect to their efficiency for screening urine. The resulting screening method proved to be a specific and sensitive procedure, enabling these analytes to be detected and identified up to 48 h after the administration of a dosage, usually encountered in doping cases.
authors.affiliation: Netherlands Institute for Drugs and Doping Research, University of Utrecht, The Netherlands.
authors.forename: M S
authors.initials: MS
authors.lastname: Leloux
authors.forename: E G
authors.initials: EG
authors.lastname: de Jong
authors.forename: R A
authors.initials: RA
authors.lastname: Maes
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D006868:Hydrolysis
chemical_list: D000319:Adrenergic beta-Antagonists