Vol 79, No 4 (2024)

Determination of the group hydrocarbon composition (saturated and aromatic hydrocarbons, resins, asphaltenes) of petroleum dispersed systems is predominantly carried out using chromatographic analysis methods: liquid adsorption chromatography, high-performance liquid chromatography, thin-layer chromatography with flame ionization detection. The specificity of standard methods developed for the analysis of petroleum feedstock and petroleum products using a particular method often results in the incompatibility of results both in terms of the nomenclature of the identified hydrocarbon groups and the determined concentration values. This review provides a comparative assessment of chromatographic methods for analyzing the group hydrocarbon composition of petroleum feedstock and petroleum products, their features, advantages, and disadvantages. The main options for modifying standard methods aimed at achieving correlation between the results obtained by different analysis methods are described.

The patterns of generating gas mixtures of polar organic compounds at the level of their MAC (several µg/m³) were studied using the method of continuous gas extraction from aqueous solutions with a known concentration in combination with dilution by a stream of diluent gas. The necessary distribution coefficients of phenol, isomeric cresols, nitrobenzene, and alkanols С₄–С₆ between the aqueous and gas phases (nitrogen) were determined. A two-stage generation scheme is proposed, based on saturating the sorbent (activated carbon) with a flow of extraction gas containing the target components at a specified concentration, followed by desorption by a flow of pure extraction gas.

Two methods for increasing the degree of hydrophilization and screening of the sorbent matrix based on a copolymer of styrene and divinylbenzene grafted with polyethyleneimine quaternized with glycidol are proposed. The first method involves the polymerization of glycidol in the functional layer by varying the pH of the reaction medium, and the second method involves modifying the matrix by oxidizing the double bonds on its surface to obtain anchor epoxy groups. It was demonstrated that in the first method, the optimal approach is the twofold addition of glycidol before and after the addition of alkali, as in this case, the first addition of glycidol is consumed for the quaternization of polyamine, and the second for polymerization in ion-exchange centers. The new method of matrix modification, combined with the developed method of creating hydrophilic layers, significantly reduced the retention of oxyhalides, haloacetic acids, and polarizable anions in ion chromatography with suppressed background conductivity and amino acids in hydrophilic chromatography up to the point of changing the elution order. The obtained stationary phases are suitable for the simultaneous determination of standard inorganic anions, oxyhalides, and anions of haloacetic or alkylphosphonic acids in ion chromatography, as well as for the separation of amino acids, sugars, and vitamins in hydrophilic chromatography.