Application of ATR-FTIR spectroscopy for the identification of chemical functional groups in kerogens and fossil resins.

Organic matters, such as oil, kerogen, fossil resins have different chemical functional groups. The complexity of chemical functional groups derives from the many sources of original contributing organic matter and long-term chemical and physical changes over geologic time. Fourier transform infrared spectrometer attenuated total reflectance (FTIR-ATR) can quantify the abundance of chemical functional groups and is a sensitive, high resolution and non-destructive analytical technique. The aim of this study was to characterize the spectral behavior and chemical structure of organic matters. In order to correlate organic matters of different types with its infrared spectra. The results show that FTIR-ATR spectra of oil contain intense aliphatic C-H stretching vibration in 2960 cm^-1,2925 cm^-1,2850 cm^-1 region relative to the C–H (CH₃) scissoring vibration at 1470 cm^-1 and C=C aromatic ring stretching vibration at 1640 cm^-1. We apply FTIR-ATR analyses for evaluating oil potential of kerogens. The longest aliphatic chains having the least amount of branching testifying to the highest oil generating potential. The similar locality of fossil resins has a similar chemical vibration ratio of C-H stretching (2925 cm^-1,2850 cm^-1) and C-H scissoring (1470 cm^-1). In consequence, the analysis providing a rapid means of assessing organic matters and oil potential, and it can also rapidly identification the botanical origin of fossil resins.