[Determination of the quantitative content of lipids in a biological material by the method of IR spectroscopy.]

A modification of the Folch method has been proposed for the quantitative determination of lipids in biological material, in which, after extraction of lipids with a chloroform / ethanol mixture, lipids are determined using IR spectroscopy. The bands corresponding to the stretching and deformation vibrations of the methyl and methylene groups of lipids and fatty acids were selected as analytical absorption bands: 1396, 1458, 2853, and 2923 cm^{- 1}. These bands do not intersect with the absorption bands of proteins ad nucleic acids, thus avoiding the stage of preliminary cleaning of lipids from non-lipid impurities. A multifactor regression model was constructed, which allows experimental data to be described with an error not exceeding 12%.