[Quality control of cod liver oil, physicochemical methods of analysis]

The control of oils and fats requires analytical processes far surpassing the traditional framework of physical properties and chemical characteristics. The control of cod liver oil is improved by the use of these procedures. The present report is devoted to the measurement of vitamin A by ultraviolet spectrophotometry and of vitamin D3 by high performance liquid chromatography, to the determination of the profile of their fatty acids and polyunsaturated fats, as well as to their measurement by liquid gas chromatography after derivatisation. The results permit the definition of the cod liver oil's quality, the differentiation between fish oils and the detection of possible changes. A technique for verifying the absence of butylhydroxyanisol and of butylhydroxytoluen is also described.