Cereal Chem 44:152 - 159.  |  VIEW ARTICLE
Determination of Oil Contents of Dry-Milled Corn Fractions by Gas-Liquid Chromatography.

L. T. Black, G. G. Spyres, and O. L. Brekke. Copyright 1967 by the American Association of Cereal Chemists, Inc. 

A method was developed to determine the oil content of dry-milled corn fractions by gas-liquid chromatography (GLC). Oil in ground corn was extracted and transesterified to the methyl esters and the transesterification mixture analyzed directly by GLC. Corn oil samples treated identically (transesterified) served as standards for the determination. The transesterification reagents were a mixture of methanol containing hydrogen chloride gas with dimethoxypropane and benzene. The liquid phase for the gas- chromatographic analysis was silicone gum rubber SE-30. The precision for the method is high, especially below the 1% oil level, the relative standard deviation being +/- 3.6%. The GLC determination is not the limiting factor, because oil can be detected at a level less than 0.001%. The extraction-transesterification step removes at least 98% of the oil. Typical nonoil foreign matter will not interfere with the determination, since the analysis is specific for glyceride oils. The original oil content of samples containing oxidized or possibly bound oil can be determined from the methyl palmitate content. This method has also been applied to the determination of oil in other oilseed materials.