DOI: 10.21276/sajp.2018.7.9.5

Pages: 425-433

The aim of current study was the application of GC method for separation of Docosahexaenoic acid and Eicosahexaenoic acid from other fatty acids in food supplements and their further determination by percentage method. This method for quantitative analysis is based on the measuring of the area of all peaks in the chromatogram of the hydrolyzed and methylated samples and calculation of their sum, whereby the area of each peak is calculated as a percentage of the total area of the chromatographic peaks. After hydrolysis of fatty acid esters, the free forms were preesterificated with methanol solution of 14 % boron trifluoridе. For separation of Docosahexaenoic acid and Eicosahexaenoic acid from other fatty acids was applied GC method: flow rate of carrier gas: hydrogen: 45 ml/min., inlet pressure: 15 Psi, temperature programm: 140 C for 5 min, increasing the temperature to 240 C at a rate of 4 C/min, 240 C for 20 min, increasing the temperature to 280 C at a rate of 6 C/min and 280 C for 10 min. The suitability of the system was confirmed by the lack of a statistically significant difference between the values of the chromatographic parameter retention time in the analysis of Methylmyristate (SD = 0.185, RSD = 1.22 %),