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.