title: Comparison of Carr-Price analysis and liquid chromatographic analysis for vitamin A in fortified milk.
abstract: The determination of the vitamin A concentration in fortified milk was compared using Carr-Price analysis and liquid chromatography (LC). Carr-Price analysis required saponification of the sample with alcoholic potassium hydroxide, extraction with ether, and colorimetry with antimony trichloride in chloroform. LC analysis required hexane extraction of a 71% alcohol-sample solution and centrifugation at 2000 rpm. A 100 microL aliquot of the extract was analyzed on a LiChrosorb Si-60, 5 micron column, using an ethyl ether-hexane (2 + 98) mobile phase and detection at 313 nm. Each method was statistically evaluated for precision and sample-to-sample reproducibility. The LC extraction procedure was examined for efficiency. Each LC value was divided by the Carr-Price value obtained for the same sample; an average value of 0.975 with a coefficient of variation of 6.90% was obtained. It was concluded that the procedures were statistically equivalent.
mesh_terms: D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods; D004224:Diterpenes; D008892:Milk / Q000032:analysis*; D000084562:Retinyl Esters; D013053:Spectrophotometry / Q000379:methods; D014801:Vitamin A / Q000031:analogs & derivatives / Q000032:analysis*
chemical_list: D004224:Diterpenes; D000084562:Retinyl Esters; D014801:Vitamin A; C014794:retinol palmitate