LC-UV Column-Switching for Quantitation of Vitamin K₁ in Infant Formula

This study was undertaken in order to develop an analytical method for vitamin K₁ in infant formula. The content of vitamin K₁ was investigated by using a column-switching LC-UV method. A Certified Reference Material sample of infant formula containing 0.94 ± 0.04 mg kg⁻¹ of vitamin K₁ was extracted with hexane followed by enzymatic digestion of fat and precipitation of the fatty acids. The linearity of this method was calculated using five consecutive standard curves, and the coefficient of determination (r ²) was found to be 0.9995. The limit of detection (LOD) and the limit of quantitation (LOQ) was 3.31 and 11.12 μg L⁻¹, respectively. The accuracy of intra- and inter-day measurements was in the range from 96.67 to 108.67%, and the precision of intra- and inter-day measurements was less than 5.13%. The recoveries were 109.27 ± 5.92%, and the recoveries of inter-laboratory results were in the range from 97.59 ± 1.29 to 109.27 ± 5.92%. The newly developed method uses the optimum conditions required to determine the content of vitamin K₁ in infant formula.