Determination of phylloquinone and menaquinones in animal products with fluorescence detection after postcolumn reduction with metallic zinc

J Agric Food Chem. 2000 Dec;48(12):6325-31. doi: 10.1021/jf000638u.

Abstract

A high-performance liquid chromatographic (HPLC) method for the determination of phylloquinone and menaquinones in foods of animal origin is described. The K vitamers were quantified with a fluorescence detector after postcolumn reduction with metallic zinc using K1(25) as an internal standard. Extraction was done either with 2-propanol-hexane (meat and fish products) or with acid hydrolysis method (dairy products). Prior to quantification, sample extracts were purified by semipreparative HPLC; in addition, the fats of cheese and rainbow trout samples were removed with lipase hydrolysis. By this method the phylloquinone and menaquinones (MK-4 to MK-10) present in a few representative samples of different animal food groups were determined. HPLC-MS was used to confirm the identification of K vitamers. Long-chain menaquinones were found from bovine and pig livers as well as from various cheeses. The total vitamin K contents calculated as the sum of quantified K vitamers were in general low (mean content 10-100 ng/g); the highest amount was analyzed in chicken meat (600 ng/g).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chromatography, High Pressure Liquid
  • Fish Products / analysis*
  • Fluorescence
  • Meat Products / analysis*
  • Vitamin K / isolation & purification*
  • Vitamin K 1 / isolation & purification*

Substances

  • Vitamin K
  • Vitamin K 1