Calibration of GC-FID and IR spectrometric methods for determination of high boiling petroleum hydrocarbons in environmental samples

Calibration problems connected with the determination of C-20-C-44 petroleum hydrocarbons by gas chromatography - flame ionization detection (GC-FID) and IR spectrometric methods were studied in this paper. It has been found that the mass responses and mass response factors of FID determined by capillary GC- FID as well as by IR spectrometry, at wave number 2959 and 2924 cm(-1), of high boiling petroleum distillation fractions (in the range C-20-C-46) are not constant. Moreover, it was found that mass response factors for different petroleum oils that have the same boiling temperature interval might differ up to 1.5 fold both for FID and IRD methods, depending on their hydrocarbon group composition. However, calibration of the IR spectrometric method using the empirical equations proposed in DIN 38 409, Part 18, norm (for the determination of total petroleum hydrocarbons in waters polluted with high boiled petroleum fractions) gave results which overlapped within +/-10% of the expected values.