Modification of the approach to the technology of preparation of samples of milk and dairy prod- ucts for the determination of the fatty acid profile using the gas chromatography method

Abstract

The objects of the study are extractants and optimal extraction conditions that contribute to the full release of the substances being determined: the concentration and volume of the extractant, the extraction time and temperature regime. This work includes the technology of sample preparation for determining the fatty acid composition of milk with a fat mass fraction of more than 3 %, which is centrifuged for 10 minutes at 10000 rpm, 20 µl of oil is taken from the centrifuged laboratory sample into a test tube from the upper part, then dissolved in 2 cm3 of organic solvent (hexane), then mixed manually for 1-2 minutes, 100 ml of sodium methylate solution of 2 molar concentration is added to the resulting solution with a pipette and the tube is closed with a stopper, then intensively mixed manually for 2 minutes, insist for 5 minutesand filter through a paper filter the top layer containing methyl esters, the resulting solution will be ready for examination by gas chromatography. The proposed new approach to technology development reduces the sample preparation time (~19 min), reduces the amount of solvent consumed by more than 10 times, minimizes the number of actions when working with samples, and requires a minimum amount of equipment.

Keywords

• gas chromatography
• mass spectrometry
• sample preparation
• dairy products
• fatty acids
• methylation
• trans isomer