Liquid Chromatographic Analysis of Vitamin K1 in Milk-Based Infant Formula with Matrix Solid-Phase Dispersion

Abstract

A liquid chromatographic method for vitamin K1 in milk-based infant formula is described. The vitamins are extracted from infant formula by matrix solid-phase dispersion and quantitated by reversed-phase chromatography with fluorescence detection. Vitamin K1 is converted to the fluorescent hydroquinone with a postcolumn zinc reductive reactor. The limit of detection is 12 pg, and the limit of quantitation is 38 pg on-column. Linear responses were obtained in the range 0.55-22.1 ng/mL (r2 = 0.9998). Recoveries of vitamin K1 from an analyte-fortified blank material for milk-based infant formula averaged 91.7% (n = 25). The method provides a rapid, specific, and easily controlled assay for vitamin K1 in fortified infant formula.

Microwave Assisted Cloud Point Extraction for the Determination of Vitamin K Homologues in Vegetables by Liquid Chromatography with Tandem Mass Spectrometry

“…A comparison of the developed method with previously published methods for determining K vitamins in food samples by LC is shown in Table 3. Note that CPE is used for the first time to preconcentrate the K vitamins, providing, in the case of PK and MK, comparable sensitivities to those previously obtained using conventional sample treatments such as SPE 18,23,25,30 or the miniaturized procedures DLLME 13 and MSPD, 14 in a simple and rapid treatment and avoiding the use of toxic organic solvents. The analytical characteristics obtained show that UAE-CPE combined with LC-ESI-QqQ-MS/MS can be used for the routine analysis of vegetables, minimizing sample handling.…”

“…The food matrices most frequently analyzed for the determination of vitamin K are fruit and vegetable products, 5,6,9,13,15,18,19,23,26,28,30,31 vegetable oils, 6,8,12 milk products, and infant formulas. 10,12,14,21,22,29,32 Sample treatment must avoid those conditions affecting the stability of the vitamins, such as ultraviolet light, alkaline, and acid media. 2 Food matrices of a lipidic nature such as milk require a hydrolysis step.…”

“…21,29 and subsequent purification of the obtained extract by means of solid-phase extraction (SPE) have been widely discussed. 5,15,18,19,23,25,28,30 Matrix solid phase dispersion (MSPD) 9,14 and accelerated solvent extraction (ASE) 23 have been applied to extract K vitamers from different types of food. Miniaturized techniques for sample treatment allow high enrichment factors to be obtained with minimum environmental impact.…”