title: Disposable cartridge extraction of retinol and alpha-tocopherol from feedstuffs.
abstract: Automated determination of fat-soluble vitamins by modern methods such as liquid chromatography is hampered by the initial extraction step. A simple technique is proposed that allows an appreciable increase in the actual rates of determination. Feedstuff samples are first hydrolyzed in an aqueous alcohol (mainly methanol)-potassium hydroxide solution. Instead of extracting retinol and alpha-tocopherol from the hydrolysis solution by an organic solvent, an aliquot of the solution is mixed with a small volume of a strong antioxidant solution (ascorbic acid) and pipetted onto a kieselguhr disposable cartridge where it is adsorbed. Retinol and alpha-tocopherol are eluted with isooctane at normal pressure. The proposed method has been compared with conventional techniques on many feed samples.
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D001322:Autoanalysis; D006868:Hydrolysis; D012997:Solvents; D014801:Vitamin A / Q000032:analysis*; D014810:Vitamin E / Q000032:analysis*
chemical_list: D012997:Solvents; D014801:Vitamin A; D014810:Vitamin E