Group Type Analysis of Asphalt by Using Column Liquid Chromatography

A modified method for group type analysis of asphalt was tested using column liquid chromatography and verified by infrared spectrum and NMR analysi.The method allows for the detection and quantitation of saturates,aromatics,resins and asphaltine.The technique is rapid and requires minimal quantities of sample and solvent.For about 0.1 g sample,the solvent sequence is 20 mL n-heptane for saturates,35 mL n-heptane/dichloromethane((1/2.5),(V/V)) for aromatics and 30 mL dichloromethane/tetrahydrofuran (1/3,V/V) for resin.The model compounds are tetracosan for saturates,dibenzpah anthracen for aromatics and acetanilide for resin.The infrared spectrum and NMR analysis of the prepared fractions from the column liquid chromatography were in good agreement with that of pure reagents.The recovery of here model compounds were high.The proposed method was successfully applied to characterize heavy asphalt samples and showed high resolution,reliability and recovery.Some heavy asphalt were analyzed by this method,and the separated fractions were analyzed by IR and ¹HMR which showed satisfactory separation.