title: Method for the determination of vitamin K homologues in human plasma using high-performance liquid chromatography-tandem mass spectrometry.
abstract: We report here the development of a precise and sensitive method for the determination of vitamin K homologues including phylloquinone (PK), menaquinone-4 (MK-4), and menaquinone-7 (MK-7) in human plasma using HPLC-tandem mass-mass spectrometry with atmospheric pressure chemical ionization (LC-APCI-MS/MS). The method involves the use of stable isotope (18)O-labeled internal standard compounds, which were synthesized in our laboratory, and the selection of a precursor and product ion with a MS/MS multiple reaction monitoring method. The average intraassay and interassay variation values for PK, MK-4, and MK-7 were <10%. Average spiked recoveries from authentic compounds added to normal human plasma samples for PK, MK-4, and MK-7 were 98-102%. Mean plasma concentrations of PK, MK-4, and MK-7 from healthy subjects (n = 20) were 1.22 +/-0.57, 0.39 +/- 0.46, and 6.37 +/- 7.45 ng/mL, respectively. We conclude that this novel LC-APCI-MS/MS method should be useful for the evaluation of vitamin K status in postmenopausal women and elderly subjects and provides useful information for the treatment and prevention of osteoporosis with vitamin K.
authors.affiliation: Department of Hygienic Sciences, Kobe Pharmaceutical University, 4-19-1, Motoyamakita-machi, Higashinada-ku, Kobe 658-8558, Japan.
authors.forename: Yoshitomo
authors.initials: Y
authors.lastname: Suhara
authors.forename: Maya
authors.initials: M
authors.lastname: Kamao
authors.forename: Naoko
authors.initials: N
authors.lastname: Tsugawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Okano
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010024:Osteoporosis / Q000175:diagnosis; D010103:Oxygen Isotopes; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D014812:Vitamin K / Q000031:analogs & derivatives / Q000097:blood*; D010837:Vitamin K 1 / Q000097:blood; D024482:Vitamin K 2 / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D010103:Oxygen Isotopes; D024482:Vitamin K 2; D014812:Vitamin K; C030814:menatetrenone; D010837:Vitamin K 1