The chemical class compositions of the oils were determined by liquid column chromatography technique. The column was conditioned by washing with n-pentane. About 1 g of oil was separated into two fractions as pentane soluble and insoluble compounds (asphaltenes) by using n- pentane. The n-pentane soluble fractions were further separated on activated silica gel (70e230 mesh), pretreated at 105 C for 2 h prior to introduction into column. The column was eluted successively with n-pentane, toluene and methanol to produce aliphatic, aromatic and polar fractions, respectively. The oil and its column chromato-graphic fractions were analysed by using PerkineElmer 100 Model Fourier transform infrared (FTIR) spectrophotometer. The 1H-NMR spectrum of the oil was obtained at an H frequency of 400 MHz using a Bruker Avancet DPX-400 instrument. The samples were dissolved in deuterated chloroform.