title: Sensitive assay for determining plasma tenofovir concentrations by LC/MS/MS.
abstract: An LC/MS/MS assay for the determination of tenofovir (TNF) was developed and validated for use with the EDTA anticoagulated human plasma matrix. Heparin-treated plasma and serum matrices were also validated. After addition of adefovir as an internal standard, trifluoroacetic acid was used to produce a protein-free extract. Chromatographic separation was achieved with a Polar-RP Synergi, 2.0 mm x 150 mm, reversed-phase analytical column. The mobile phase was 3% acetonitrile/1% acetic acid, aq. Detection of TNF and the internal standard was achieved by ESI MS/MS in the positive ion mode using 288/176 and 274/162 transitions, respectively. The method was linear from 10 to 750 ng/ml with a minimum quantifiable limit of 10 ng/ml when 250 microl aliquots were analyzed. The usefulness of this LC/MS/MS method to routinely monitor plasma concentrations of TNF was demonstrated along with its ability to assist in the performance of pharmacokinetic studies.
authors.affiliation: Antiviral Pharmacology Laboratory, Department of Clinical Pharmacy, School of Pharmacy, University of Colorado Health Sciences Center, Denver, 80262, USA. tom.delahunty@uchsc.edu
authors.forename: Tom
authors.initials: T
authors.lastname: Delahunty
authors.forename: Lane
authors.initials: L
authors.lastname: Bushman
authors.forename: Courtney V
authors.initials: CV
authors.lastname: Fletcher
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015658:HIV Infections / Q000097:blood; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D063065:Organophosphonates / Q000097:blood* / Q000493:pharmacokinetics; D012015:Reference Standards; D018894:Reverse Transcriptase Inhibitors / Q000097:blood* / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity; D000068698:Tenofovir
chemical_list: D063065:Organophosphonates; D018894:Reverse Transcriptase Inhibitors; D000068698:Tenofovir; D000225:Adenine