title: Identification and quantification of tamoxifen and four metabolites in serum by liquid chromatography-tandem mass spectrometry.
abstract: We have developed a method for the determination of tamoxifen (tam) and its metabolites 4-hydroxytamoxifen (4OHtam), N-demethyltamoxifen (NDtam), N-dedimethyltamoxifen (NDDtam), tamoxifen-N-oxide (tamNox), and 4-hydroxy-N-demethyltamoxifen (4OHNDtam) in 50 microl human serum. Serum proteins were precipitated with acetonitrile. Deuterated-tamoxifen (D5 tam) was added as internal standard. Sample supernatant was injected into an on-line reversed-phase extraction column coupled with a C18 analytical column and analytes were detected by tandem mass spectrometry. The lower limits of quantification were 0.25 ng/mL for 4OHtam, NDtam and tam, 1.0 ng/mL for NDDtam and tamNox. Ranges of within- and between-day variation were 2.9-15.4% and 4.4-12.9%, respectively.
authors.affiliation: Hormone Laboratory, Haukeland University Hospital, N-5021 Bergen, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Gjerde
authors.forename: E R
authors.initials: ER
authors.lastname: Kisanga
authors.forename: M
authors.initials: M
authors.lastname: Hauglid
authors.forename: P I
authors.initials: PI
authors.lastname: Holm
authors.forename: G
authors.initials: G
authors.lastname: Mellgren
authors.forename: E A
authors.initials: EA
authors.lastname: Lien
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy; D005591:Chemical Fractionation / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013629:Tamoxifen / Q000031:analogs & derivatives / Q000097:blood* / Q000378:metabolism / Q000627:therapeutic use
chemical_list: D013629:Tamoxifen; C016601:afimoxifene; C035830:tamoxifen N-oxide; C028787:N-desmethyltamoxifen