Investigation of petroleum absorption spectra with comparation to isooctane in the range 1090-1220 nm

The experimental investigations of different types petroleums absorption spectra was carried out (AI-80, A-92, AI-95) with comparation to the pure hydrocarbon - isooctane for the infrared wavelength range 1090-1220 nm where second overtones methyl (CH3), methylene (CH2), aromatic (CH) groups are. The achieved differential spectra allow to select CH3, CH2 and CH hand maximums reveal the forth maximum of unknown nature. The connection of petroleum octane number absorption magnitude is proved.