title: Liquid chromatographic method for analysis of all-rac-alpha-tocopheryl acetate and retinyl palmitate in milk-based infant formula using matrix solid-phase dispersion.
abstract: A liquid chromatographic method is described for analysis of all-rac-alpha-tocopheryl acetate, tocopherols, and retinyl palmitate in milk-based infant formula. The vitamins are extracted from infant formula without saponification by matrix solid-phase dispersion and quantitated by normal-phase chromatography with fluorescence detection. Retinyl palmitate and vitamin E are quantitated isocratically with mobile phases of 0.125% (v/v) and 0.5% (v/v) isopropyl alcohol in hexane, respectively. Results were similar to the certified and non-certified ranges for all-rac-alpha-tocopheryl acetate, retinyl palmitate, and tocopherols in the infant formula standard reference material (SRM) 1846. Results also compared favorably with the label declaration on a retail infant formula. Recoveries were determined on an analyte-fortified zero control reference material for milk-based infant formula and averaged 96.8% (n = 30) for retinyl palmitate and 91.5% (n = 25) for all-rac-alpha-tocopheryl acetate. Examination of 5 concentrations for each analyte gave results that were linear (r = 0.999) over the concentration examined, with coefficients of variation ranging from 1.02 to 5.86%. The method provides a rapid, specific, and easily controlled assay for analysis of retinyl palmitate and vitamin E in fortified infant formula. Additionally, the method minimizes solvent use by using only 14 mL solvent per extraction.
authors.affiliation: U.S. Food and Drug Administration, Atlanta Center for Nutrient Analysis, GA 30309, USA.
authors.forename: G W
authors.initials: GW
authors.lastname: Chase
authors.forename: A R
authors.initials: AR
authors.lastname: Long
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000032:analysis*; D000975:Antioxidants / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods*; D004224:Diterpenes; D005504:Food Analysis / Q000379:methods; D007225:Infant Food / Q000032:analysis*; D008892:Milk; D000084562:Retinyl Esters; D013050:Spectrometry, Fluorescence; D024505:Tocopherols; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000032:analysis; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000032:analysis; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
chemical_list: D016588:Anticarcinogenic Agents; D000975:Antioxidants; D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; D014810:Vitamin E; C014794:retinol palmitate; D024502:alpha-Tocopherol; D024505:Tocopherols