Determination of nitrogen in vegetable oils

Summary Hydrolysis with alcoholic hydrochloric acid quantitatively converts the nitrogen of crude soybean lecithin to a water-dispersible form. This alcoholic-acid hydrolysis also converts the nitrogen in large amounts of crude soybean oil to a water-dispersible form which can then be separated and digested with a minimum amount of sulfuric acid by the Kjeldahl procedure. With careful control of both reagents and blank determinations, as little as 0.1 mg. of nitrogen can be measured with a precision of about 10%. The details of the method are given and it is applied to a series of soybean oils after various treatments and to three kinds of salad oils. Presented by Dr. R. T. Milner of the Northern Regional Research Laboratory at the Spring Meeting of the American Oil Chemists' Society at New Orleans, Louisiana, May 20–22, 1947. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry. Agricultural Research Administration, U. S. Department of Agriculture.