| Autor: |
Hivon, Katharine J., Quackenbush, F. W. |
| Zdroj: |
Journal of the American Oil Chemists' Society; June 1957, Vol. 34 Issue: 6 p310-314, 5p |
| Abstrakt: |
A method has been developed to overcome difficulties in the analysis of corn oil for tocopherol. The poor recovery of tocopherol added to corn oil prior to the Parker-McFarlane treatment does not occur with the present method, and the absorbance drift which occurs when crude corn oil reacts with iron and dipyridyl is largely eliminated. The intefering substance responsible for the drift did not distill appreciably in a molecular still at 170°C., and attempts to remove it from the oil by selective adsorption or solvent extraction were unsuccessful. It was extractable with dilute potassium hydroxide from a hexane solution of the oil and could be transferred from the alkaline extract to benzene. If the alkaline extract were acidified and then shaken with benzene, a much larger amount of the substance could be transferred. Extracts containing the substance showed strong absorption at wave-lengths between 290 and 315 millimicrons. Alkali treatment of the oil and subsequent adsorption on diatomacous earth reduced the content of interfering constituents to permit analyses for total tocopherol by the Emmerie-Engel method. By using this method, it was found that the oil from different corn inbreds and crosses varied over a six-fold range in tocopherol content. |
| Databáze: |
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