Use of Partition Coefficients in a Hexane–Acetonitrile System in the GC–MS Analysis of Polyaromatic Hydrocarbons in the Example of Delayed Coking Gas Oils

Abstract

The partition coefficients’ application in the hexane–acetonitrile system as an additional identification feature of polyaromatic hydrocarbons in the review gas chromatography–mass spectrometry analysis of delayed coking gas oils has been considered. The UNIFAC model was used to calculate the partition coefficients of polycyclic aromatic hydrocarbons. It is shown that methyl derivatives of naphthalene, fluorene, anthracene, and pyrene can be identified with an accuracy up to several methyl groups by the position of the figurative point on the partition coefficient–retention index plane. The experimental values of partition coefficients for naphthalene, anthracene, and pyrene are 0.82, 0.78, and 0.77, respectively. The appearance of one methyl group increases the partition coefficient by 0.15–0.2 on average. A total of 53 polyaromatic hydrocarbons were identified in this way.

Comparison of UNIFAC and LSER Models for Calculating Partition Coefficients in the Hexane–Acetonitrile System Using Middle Distillate Petroleum Products as an Example

“…In addition, an important advantage of using this system is quick phase separation. The efficiency of this method has been demonstrated in multicomponent mixtures: various essential oils and aromatized petroleum products. , The main complication in using this method is the lack of experimental partition coefficients for various substances. For this purpose, various linear regression models are often used which makes possible substance partition coefficient prediction based on its known physical properties .…”