Method for the Determination of Vitamin K Homologues in Human Plasma Using High-Performance Liquid Chromatography-Tandem Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 77; no. 3; pp. 757 - 763
• Main Authors: Suhara, Yoshitomo, Kamao, Maya, Tsugawa, Naoko, Okano, Toshio
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.02.2005
• Subjects: Analytical chemistry; Calibration; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography; Chromatography, High Pressure Liquid - methods; Exact sciences and technology; Fluids; Humans; Ionization; Liquid chromatography; Mass spectrometry; Mass Spectrometry - methods; Monitoring methods; Osteoporosis; Osteoporosis - diagnosis; Other chromatographic methods; Oxygen Isotopes; Plasma; Reference Standards; Reproducibility of Results; Sensitivity and Specificity; Spectrometric and optical methods; Spectrometry, Fluorescence - methods; Stable isotopes; Vitamin K - analogs & derivatives; Vitamin K - blood; Vitamin K 1 - blood; Vitamin K 2 - analogs & derivatives; Vitamin K 2 - blood; Vitamins; Human; Plasma; Atmospheric pressure; Internal standard; Mass spectrometry MS/MS; HPLC chromatography; Liquid chromatography; Phylloquinone; Precursor; Chemical ionization; Monitoring; Vitamin K
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac0489667

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 18O-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.