Vitamin K is a fat-soluble vitamin. Vitamin K1 (phylloquinone) and vitamin K2 (menaquinones) are both naturally occurring, with vitamin K1 being abundant in green plants, and K2 abundant in cheese and fermented soybeans. K2 is menaquinone-n (MK-n); according to the number of isoprenes in its side chain. In general, MK-4 is abundant in fermented soybeans and MK-7 is abundant in fermented soybeans.
Vitamin K3 is an industrially synthesized compound that does not exist in nature.
Vitamin K was analyzed by solvent extraction and injection onto a solid-phase extraction-purified test solution into a column-switching HPLC system.
n the HPLC system, a switching valve is controlled to facilitate the concentration of target components and removal of contaminants.