A light cycle oil (LCO) fraction in the boiling point range 220-337 degreesC was successfully characterized in detail with respect to 29 individual aromatic sulphur compounds and total sulphur content using high-resolution gas chromatography with sulphur chemiluminescence detection (HRGC-SCD). The resulting chromatogram, although very complex with hundreds of different alkyl-substituted aromatic sulphur derivatives, was well resolved owing to the high performance Equity-1 column and the optimised GC method. A shift in the sulphur distribution towards the heavier homologues was observed due to the origin of the LCO, derived from hydrotreated vacuum gas oil. (C) 2004 Elsevier B.V. All rights reserved.