CAPILLARY COLUMN GAS-CHROMATOGRAPHIC RESOLUTION OF ISOMERIC POLYCYCLIC AROMATIC SULFUR HETEROCYCLES IN A COAL LIQUID

Fused silica capillary columns coated with nonpolar (SE-52); polar (Superox 20 M); and liquid crystal (BBBT, BMBT, and BHxBT) stationary phases and their mixtures were evaluated for the separation of isomeric polycyclic aromatic sulfur heterocycles containing three to five rings. Although columns containing Superox 20M or mixtures of Superox 20M in SE-52 were able to resolve all 3-ring isomers, no single column could resolve all of either the 4-ring or 5-ring isomers. Fortunately, the compounds that were unresolved on pure SE-52 could be resolved on a 50% mixture of BBBT in SE-52, making possible the positive identification of these compounds. Thus, the 3-, 4-, and 5-ring polycyclic aromatic sulfur heterocycles in a selected coal liquid were determined using three columns coated with pure SE-52, 50% superox 20M in SE-52, and 50% BBBT in SE-52.