| Title | Measurement of Deuterium-Labeled Phylloquinone in Plasma by High-Performance Liquid Chromatography/Mass Spectrometry. | | Author(s) | Fu X, Peterson JW, Hdeib M, Booth SL, Grusak MA, Lichtenstein AH, Dolnikowski GG | | Institution | Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, Massachusetts 02111, and U.S. Department of Agriculture/Agricultural Research Service Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030. | | Source | Anal Chem 2009 Jul 1; 81(13):5421-5425. | | Abstract | Phylloquinone (vitamin K(1)) is a lipophilic compound present in plasma at low concentrations, which presents technical challenges for determining its bioavailability or metabolic fate using stable isotopes. We developed a method to simultaneously measure unlabeled and deuterium-labeled phylloquinone concentrations in plasma specimens using high-performance liquid chromatography/mass spectrometry with atmospheric pressure chemical ionization (LC-APCI/MS). Phylloquinone was extracted from plasma using hexane, further purified by solid-phase extraction, and then quantified using high-performance liquid chromatography with an APCI/MS as a detector. Plotting the expected versus the measured amount of serial dilutions of either unlabeled or labeled phylloquinone gave correlation coefficients (R) of 0.999 for both compounds. The minimum detectable concentrations of unlabeled and labeled phylloquinone were 0.05 and 0.08 pmol/injection, respectively. Pooled plasma samples spiked with between 0.5 and 32 nmol phylloquinone/L gave average recoveries of 96.7% with 5.4% relative standard deviation (RSD) for unlabeled phylloquinone and 96.2% with 6.6% RSD for labeled phylloquinone. Plasma phylloquinone concentrations determined by LC-fluorescence and LC-APCI/MS methods from healthy subjects (n = 17) were not statistically different (P = 0.13). The LC-APCI/MS method is a sensitive technique for simultaneous determination of both unlabeled and labeled phylloquinone and can be applied to bioavailability studies. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19563214 |
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