title: [Determination of retinol and alpha-tocopherol in milk and milk products using high-pressure liquid chromatography after saponification in serum vials].
abstract: An improved procedure is described for the determination of retinol and alpha-tocopherol in milk and dairy products using high-pressure liquid chromatography (HPLC). Samples are saponified in sealed 10-ml serum vials in the absence of oxygen, cooled and neutralized by injecting glacial acetic acid into the system. Retinyl acetate and 5,7-dimethyltocol respectively are used as the internal standards. The solution is extracted with hexane and the organic phase is cleaned up on a sodium sulphate/aluminium oxide column. The solution is evaporated under vacuum and dissolved in ethanol for HPLC analysis. A short reversed-phase column packed with RP-18, using methanol as the eluent, allows fast separations of both the vitamins.
authors.affiliation: Eidgenössische Forschungsanstalt für Milchwirtschaft, Liebefeld-Bern, Schweiz.
authors.forename: N
authors.initials: N
authors.lastname: Bilic
authors.forename: R
authors.initials: R
authors.lastname: Sieber
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003611:Dairy Products / Q000032:analysis*; D005260:Female; D007202:Indicators and Reagents; D008892:Milk / Q000032:analysis*; D014801:Vitamin A / Q000032:analysis*; D014810:Vitamin E / Q000032:analysis*
chemical_list: D007202:Indicators and Reagents; D014801:Vitamin A; D014810:Vitamin E
vernacular_title: Bestimmung von Retinol und alpha-Tocopherol in Milch und Milchprodukten mit Hilfe der Hochdruck-Flüssigchromatographie (HPLC) nach Verseifung in Serumfläschchen.