Forty four samples of type C gasoline, obtained from service stations of five different distributors, and samples of type A gasoline were analyzed by gas chromatography-flame ionization detection (GC-FID) using a low-polarity capillary column. Linear retention indices (LRI) were calculated, and individual components of the gasoline samples were characterized using a detailed hydrocarbon analysis software (Star-DHA (TM)). The quantitative data obtained by the chromatographic method were compared with data obtained by official standard methods. Hierarchical cluster analysis was used to determine the degree of similarity between the samples. Detailed hydrocarbon analysis revealed that some of the samples from service stations were probably adulterated with organic solvents. (C) 2008 Elsevier Ltd. All rights reserved.