Vitamin K1 (phylloquinone) content of commonly consumed foods in Korea were determined by solvent extraction followed by reversed-phase liquid chromatography using post-column derivatization and fluorescence detection. Samples were obtained in the years of 2013 and 2015. In this study, 46 vegetables, 14 fruits, and 6 legumes were analyzed. Relatively higher amounts of vitamin K1 were found in sweet potato leaves, green kiwi, and mung beans among vegetables, fruits, and legumes, respectively. The content of vitamin K1 in vegetables including spinach, broccoli, and potato ranged from non-detectable (ND) to 1,467.3 μg/100 g. The content of vitamin K1 in fruits ranged from ND to 42.7 μg/100 g. The content of vitamin K1 in legumes, including soybeans, mung beans and peas ranged from 1.7 to 63.4 μg/100 g. In addition, the analytical method validation parameters including recovery, reproducibility, repeatability, peak purity, and linearity were calculated to ensure the method's validity. The results showed high linearity with a correlation coefficient of 0.9999. Overall recovery was close to 100% (n=5). This study revealed reliable vitamin K content in commonly consumed foods in Korea for a nutritional information and food composition database.

Keywords: vitamin K, phylloquinone, HPLC, analysis, method validation