Identification of powdered products by gas chromatography method with preliminary sample derivatization

The article presents the results of research aimed at developing a method for identifying the unabi fruit variety from which the powders were made. The solution to this problem is relevant for all powders from raw materials of plant origin, which are used as functional additives. In the work, powders were studied from a variety that is conventionally named “Krasnodar” in the main region of its cultivation and from the “Chinese-2” variety, which is widespread in the Crimea, Krasnodar Territory, and the Rostov Region. In addition, powders from promising new breeding varieties of the Nikitsky Botanical Garden were investigated. In preparing samples for gas chromatographic studies, samples of powders were prepared by the derivatization method. Based on an analytical review of derivatization methods used by foreign and domestic researchers, the silylation method was chosen. Silyl reactants react with both alcohols and acids to form volatile, easily separated trimethylsilyl ethers. The methodology for sample preparation used in the work was as follows: the sample extract with 50 % ethanol was dried in vacuum at 38 °C, and then treated with 1,1,1,3,3,3-hexamethyldisilazane in a mixture of 1 ml of pyridine and 1 ml acetonitrile in the presence of trifluoroacetic acid at 60 °C for 1 hour. The resulting solution was placed in a sample chromatograph. To identify the composition of the components of powders from unabi fruit, the retention times of a series of calibration analyzes of model mixtures of a given composition were previously determined. Calculation of the component content by the average peak area was carried out after calibration without adjustments for specific sensitivity. An analysis of the chromatographic examination data showed that the studied chemical composition of powders from unabi fruits differs not only quantitatively, but also qualitatively. To identify the unabi variety from which the powder was prepared, one can propose a spectrum of the main components that are absent and present on the chromatogram. Based on the studies, a matrix was proposed for identifying powders from unabi fruits by variety based on the lack of individual components of their biochemical composition.