title: Development of an LC-MS method for measuring TNF in human vaginal tissue.
abstract: A sensitive, accurate, and precise liquid chromatography-mass spectrometry assay for the determination of tenofovir (TNF) in human vaginal tissue was developed and validated. After homogenization of the tissue, solid-phase extraction on Varian Bond Elut-C(18) column was used for sample clean up. Chromatographic separation of TNF and the internal standard (tolbutamide) was achieved with a Varian Polaris 3C(18)-A reversed-phase analytical column (150 mm x 2 mm). A gradient method using 0.1% formic acid in water and 0.1% formic acid in acetonitrile was employed. Detection of TNF and tolbutamide was achieved by electrospray ionization mass spectrometry in the positive ion mode using 288.05 and 271.00 m/z, respectively. Linear TNF calibration curves were obtained between 1-1,000 ng/mL with a correlation coefficient (r(2)) greater than 0.999. Intra- and inter-day accuracy for TNF ranged from 89.7% and 109.4% and from 97.3% and 104.9%, and precision ranged from 1.3% and 10.9% and 2.6% and 9.0%, respectively. This is the first validated method developed to quantitate TNF in human tissues.
authors.affiliation: Korea Food and Drug Administration, Department of Pharmacology. sunok7@daum.net
authors.forename: S O
authors.initials: SO
authors.lastname: Choi
authors.forename: N
authors.initials: N
authors.lastname: Rezk
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: A D M
authors.initials: AD
authors.lastname: Kashuba
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000032:analysis; D019380:Anti-HIV Agents / Q000032:analysis*; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D063065:Organophosphonates / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D000068698:Tenofovir; D014621:Vagina / Q000737:chemistry*
chemical_list: D019380:Anti-HIV Agents; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine