FIELD: medicine, analytical biochemistry. ^ SUBSTANCE: invention is designated for determination of composition of fatty acids in biological fluids of body. Method involves treatment of blood with the mixture chloroform-methanol in the ratio 2:1, hydrolysis and methylation of lipids in solution of sulfuric acid and methanol at 80oC, cooling, treatment of methylated sample with hexane-containing solvent, drying in nitrogen flow and carrying out gas-chromatography separation of fatty acids. Hydrolysis and methylation of lipids is carried out in a wet chamber for 6 h, treatment of the cooled methylated sample is carried out for 30 min in the presence of hexane and distilled water. Gas-chromatography separation of fatty acids is carried out using immobile polar phase of 20% diethylene glycol-succinate in the device Chromatron N-AW-DMCS at temperature of glass column thermostat 180oC. Invention provides enhancing sensitivity of method by elevating quantitative yield and expanding spectrum in determination of fatty
