title: Gas chromatographic-tandem mass spectrometric determination of acetylsalicylic acid in human plasma after oral administration of low-dose aspirin and guaimesal.
abstract: A fully validated gas chromatographic-tandem mass spectrometric (GC-MS-MS) method is described for the accurate determination of acetylsalicylic acid (ASA) in human plasma after a single low-dose oral administration of aspirin or guaimesal, an ASA releasing prodrug. ASA and the newly prepared O-[2H3]-acetylsalicylic acid (d3-ASA) used as internal standard were determined in 100-microl aliquots of plasma by extractive pentafluorobenzyl (PFB) esterification using PFB bromide and tetrabutylammoniumhydrogen sulphate as the esterifying and ion-pairing agent, respectively, and by GC-MS-MS analysis in the negative-ion chemical ionization mode. The overall relative standard deviations were below 8% for ASA levels in the range 0-1 microg/ml plasma. Mean accuracy was 3.8% for ASA levels within the range 0-100 ng/ml. The limit of quantitation of the method was determined as 200 pg/ml ASA at an accuracy of 5.5% and a precision of 15.2%. The limit of detection was determined as 546 amol of ASA at a signal-to-noise ratio of 10:1.
authors.affiliation: Institut für Klinische Pharmakologie, Medizinische Hochschule Hannover, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Tsikas
authors.forename: K S
authors.initials: KS
authors.lastname: Tewes
authors.forename: F M
authors.initials: FM
authors.lastname: Gutzki
authors.forename: E
authors.initials: E
authors.lastname: Schwedhelm
authors.forename: J
authors.initials: J
authors.lastname: Greipel
authors.forename: J C
authors.initials: JC
authors.lastname: Frölich
mesh_terms: D001241:Aspirin / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics; D004146:Dioxanes / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D011355:Prodrugs / Q000008:administration & dosage*; D012680:Sensitivity and Specificity
chemical_list: D004146:Dioxanes; D011355:Prodrugs; C043484:guaimesal; D001241:Aspirin