title: Sensitive determination of piritramide in human plasma by gas chromatography.
abstract: A selective and sensitive method for the determination of piritramide in human plasma is described. A 1-ml aliquot of plasma was extracted with 10 ml of hexane-isoamyl alcohol (99.5:0.5, v/v) (extraction efficiency 86%) after addition of 50 microliters of 2 M ammonia and 20 microliters of aqueous strychnine solution (100 ng per 10 microliters) as internal standard. Gas chromatography was performed with J&W DB-1, 30 m x 0.53 mm I.D. separation column, film thickness 1.5 microns, using an nitrogen-phosphorus-sensitive detector. The assay was linear in the concentration range 3.75-2250 ng/ml (r = 0.999), with a lower limit of detection of 1-2 ng/ml. The precision was determined using spiked plasma samples (10 and 50 ng/ml), with coefficients of variation of 3.5 and 3.1% (intra-day; n = 5) and 4.6 and 4.1% (inter-day; n = 4). In the range 3.75-150 ng/ml, the accuracy of the assay was 3.36%. The method was used for the determination of piritramide plasma concentrations in patients receiving intra- or post-operative analgesia.
authors.affiliation: Department of Pharmacology and Toxicology, University of Göttingen, Germany.
authors.forename: H C
authors.initials: HC
authors.lastname: Michaelis
authors.forename: D
authors.initials: D
authors.lastname: Kietzmann
authors.forename: H
authors.initials: H
authors.lastname: Neurath
authors.forename: U
authors.initials: U
authors.lastname: Jongepier
authors.forename: B
authors.initials: B
authors.lastname: Schilling
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D006801:Humans; D010892:Pirinitramide / Q000097:blood*
chemical_list: D010892:Pirinitramide