THE STUDY BY GAS-LIQUID CHROMATOGRAPHY OF THE TOTAL CONTENT OF ALKANES, ARENES AND ISOPRENOID ALKANES IN PETROLEUM PRODUCTS BEFORE AND AFTER THEIR BURNOUT IN FIRES

The compositions of petroleum products obtained from different oil fractions were studied by gas-liquid chromatography. It is shown, that in order to establish the nature of the oil product before and after exposure to high temperatures in the fire-technical examination, it is necessary, along with the identification of peaks on chromatograms by chromatographic parameters, to process them using the internal normalization method. To establish the nature of the oil product and the fraction of oil from which this oil product was obtained, it was proposed to group all identified hydrocarbons into three main groups (alkanes, arenes, isoprenoids). To determine from which fraction of oil the oil product was obtained, it is sufficient to estimate the relative content of the selected groups. For petroleum products of the gasoline fraction, the group of arenes is the predominant group, and for petroleum products of the medium distillate fractions of oil, the group of alkanes predominates in their compositions. To determine the type of petroleum product both before and after exposure to high temperatures in the fire zone, it is sufficient to determine the alkane whose content in the alkane group is maximum, as well as to analyze the content of arene subgroups and identify the arene subgroup whose contribution to the composition of the oil product is maximum. In addition, to confirm that an oil product belongs to gasoline or diesel fuels, it is sufficient to detect in its composition a group of tetramethylbenzenes or alkanes of an isoprenoid structure, respectively.