title: Liquid chromatographic determination of vitamin K1 in infant formulas and milk.
abstract: Vitamin K1 in infant formulas and milk products is determined by reversed-phase liquid chromatography (LC) with UV detection. The sample is hydrolyzed enzymatically, and the vitamin is extracted with hexane. Fractionation by normal-phase semi-preparative LC is followed by analytical LC, with quantitation by the internal standard technique. Recovery of the analyte was 97.4 +/- 2.8%. Linearity was established between 0.05 and 4.0 micrograms/mL. The limit of quantitation is 0.5 microgram/100 g for milk powder, which allows the method to quantitate endogenous levels of vitamin K1.
authors.affiliation: Anchor Products, Waitoa, New Zealand.
authors.forename: H E
authors.initials: HE
authors.lastname: Indyk
authors.forename: V C
authors.initials: VC
authors.lastname: Littlejohn
authors.forename: R J
authors.initials: RJ
authors.lastname: Lawrence
authors.forename: D C
authors.initials: DC
authors.lastname: Woollard
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D007231:Infant, Newborn; D008892:Milk / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D010837:Vitamin K 1 / Q000032:analysis*
chemical_list: D010837:Vitamin K 1