Determination of endogenous vitamin K (phylloquinone and menaquinone-n) in plasma by high-performance liquid chromatography using platinum oxide catalyst reduction and fluorescence detection

Circulating Levels of Vitamin K1, Menaquinone-4, and Menaquinone-7 in Healthy Elderly Japanese Women and Patients With Vertebral Fractures and Patients With Hip Fractures

“…Vitamin K1, menaquinone-4 (MK4), and menaquinone-7 (MK7) were measured by HPLC. The method is based on a hydrogen gas-saturated mobile phase with¯uorescence after post-column reduction by a platinum oxide catalyst column (12). The detection limits were 0.1 ng/ml for vitamin K1 and MK-4, and 0.4 ng/ml for MK-7.…”

Quantification of fat-soluble vitamins in human breast milk by liquid chromatography–tandem mass spectrometry

“…2. Under these conditions, MRM At present, standard assay methods are HPLC with fluorescence detection for RE [28], tocopherol [29] and vitamin K derivatives [30] and HPLC with visible detection for ␤-carotene [31]. For the determination of vitamin D compounds, HPLC with ultraviolet detection [15], competitive protein binding assay (CPBA) [16], radio immunoassay (RIA) [17] and enzyme immunoassay (EIA) [18] are used widely; however, in the comprehensive evaluation of the nutritional status of fat-soluble vitamins, each vitamin needs to be measured separately.…”

Determination of plasma Vitamin K by high-performance liquid chromatography with fluorescence detection using Vitamin K analogs as internal standards

“…A solution of 1 g (NH 4 ) 2 S 2 O 8 in 10 mL water was added dropwise over 90-120 min to a stirred suspension of 10 mL water, 20 mL acetonitrile, 0.25 g AgNO 3 , 0.2 g Vitamin K 3 (2-methyl-1,4-naphthoquinone) and 1.5 mmol fatty acid (n = 13,14,15,16,18,19,20,23) at 65-75 • C. After stirring for another 30 min, the resulting mixture was cooled, extracted with ether, washed with water, dried, filtered, and concentrated. Purified products with yield of 50-65% as yellow needles were obtained after flash chromatography through silica gel 60 (Merck, Darmstadt, Germany) using hexane-ethyl acetate (20:1, v/v) and recrystallization.…”

“…In addition, MK-4 has received governmental approval for use as an agent for the treatment of osteoporosis in Japan. Thus, measurement of MK-4 Previously, several methods for separation and determination of Vitamin K by thin layer chromatography (TLC) [17], gas liquid chromatography (GLC) [18,19] and highperformance liquid chromatography (HPLC) with ultraviolet (UV) detection [20], fluorescence detection [21][22][23][24][25], electrochemical detection [26][27][28][29] and mass spectrometric detection [30] were reported. Recently, we have developed a method for the determination of Vitamin K in human plasma by liquid chromatograpy-atmospheric pressure chemical ionization/mass spectrometry (LC-APCI/MS) [31].…”