title: Toxicological detection of ibuprofen and its metabolites in urine using gas chromatography-mass spectrometry (GC-MS).
abstract: Ibuprofen, (R,S)-2-(4-isobutylphenyl)propionic acid, is a non-opioid analgesic which is prescription-free available in pharmacies since 1989. Consequently, use and misuse of this analgesic strongly increased. For diagnosis of an abuse or an intoxication a GC-MS procedure was developed for the toxicological detection of ibuprofen in urine after extraction at pH 5 and methylation. For screening, mass chromatography with the masses m/z 220, 161 (methylated ibuprofen), 178, 119 (methylated hydroxy ibuprofen) and 264, 145 (methylated carboxy ibuprofen) was used to indicate the presence of these compounds in urine. The identity of the peaks underlying full mass spectra was confirmed by comparison with the reference spectra using computer library search. After ingestion of one single oral dose of 400 mg ibuprofen, the parent compound could be detected for 27 to 34 h, hydroxy ibuprofen for 34 to 40 h and carboxy ibuprofen for 5 to 6 d. Using this procedure ibuprofen which was taken even several days ago could be detected.
authors.affiliation: Institut für Pharmakologie und Toxikologie, Universität des Saarlandes, Homburg, Saar.
authors.forename: H H
authors.initials: HH
authors.lastname: Maurer
authors.forename: T
authors.initials: T
authors.lastname: Kraemer
authors.forename: A
authors.initials: A
authors.lastname: Weber
mesh_terms: D001711:Biotransformation; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007052:Ibuprofen / Q000493:pharmacokinetics / Q000506:poisoning / Q000652:urine*
chemical_list: D007052:Ibuprofen