Efficient and Eco-friendly Analytical Procedure for Vitamin K in Milk, Powdered Infant Formula, Liquid Infant Formula and Plant Oil (2): Reduction in On-duty-hours for Silica Gel Column Pretreatment Using an Automated Solid Phase Extraction Sytstem

Vitamin K is a generic term for several fat-soluble molecules found in natural and processed foods, playing an important role in human health for blood coagulation and bone metabolism. Although vegetable oils contain only phylloquinone (vitamin K1), milk and infant formula contain not only a phylloquinone but also menaquinone-4 (vitamin K2), which has a polarity more similar to that of triglyceride and impurities, therefore requiring silica gel column chromatography before HPLC analysis can be performed. By focusing on silica gel particle size to reduce the required quantity of silica gel and organic solvent, we have reported an efficient analytical procedure for quantification of phylloquinone and menaquinone-4. However, the procedure left room for improvement in terms of the on-duty-hours required for manual pretreatment by the operator. Accordingly, we have now developed a more time-efficient analytical procedure using an automated solid phase extraction system, which frees the operator from the time required for manual chromatography pretreatment. Furthermore, by examining more closely the conditions required for this system, we have developed a better procedure capable of reducing the required quantity of silica gel and organic solvent for vitamin K analysis in milk, powdered infant formula, liquid infant formula and plant oils, thus making it more ecofriendly.