Application of infrared spectrum for rapid classification of dominant petroleum hydrocarbon fractions for contaminated site assessment

Abstract In this study, the infrared spectrum (4000–400 cm −1 ) was applied to identify and classify the different alkanes based on carbon chain length (C n ). It was found there were two bands coherent to the doublet at location 2954 and 2872 cm −1 , respectively can be applied to identify the fraction of carbon chains. From C 20 to C 37 , by the increase of the C n , the intensities of the two bands were reduced as demonstrated. There were another two doublets existed at the region from 1480 to 1450 cm −1 and the region at 750 and 730 cm −1 . It was observed the intensity of one coherent band at each of these regions was increased following the increase on the C n . The bands center at 1462 and 730 cm −1 were increased from C 20 to C 37 . The intensity ratio of the coherent bands can be applied to identify the C n. Successfully identify four different petroleum products with different fractions of carbon chains in soil samples, is evidence the theory can be applied to investigate the fraction of carbon chains in soil. Coupling with handheld FTIR, it is possible to rapidly estimate the dominant fraction of C n in soil in field.