Different methodologies. based on planar chromatography/detection with densitometry, have been used to analyse compound classes (also known as hydrocarbon group type (HGT)) in samples coming from petroleum and coal conversion. The main problem encountered to analyse these samples is the choice of standard: because of the high variability of the signal that is dependent of molecular structure, one pure hydrocarbon does not reflect the response of a mixture. However, a step based on thin layer chromatography at preparative scale has allowed the fractionation of sample to obtain its derived standards. After this, alkanes have been quantified by fluorescence in presence of berberine sulfate and aromatic compounds have been detected by UV after separation by high performance thin layer chromatography (HPTLC) at analytical scale, The feasibility of the planar chromatography has been tested. The quantitative results obtained for different samples are in agreement with those provided using well-established techniques in the petrochemical industry and the coal-derived product (CDP) analysis. (C) 2002 Elsevier Science B.V. All rights reserved.