Five modes of operation of the Nicolet 7199 Fourier Transform Infrared Spectrophotometer have been evaluated for application in analysis of the chemical structure of accelerated storage/thermal deposits produced by jet fuels. Using primarily the absorption and emission modes, the effects of fuel type, stress temperature, stress time, type of spiking agent, spiking agent concentration, fuel flow, and post-depositional treatment on the chemical nature of fuel deposits have been determined. Helmick, L. S. and Seng, G. T. Glenn Research Center NASA-TM-83773, E-2200, NAS 1.15:83773 RTOP 505-31-42...

The Fourier Transform Infrared Spectometry (FTIR) with a horizontal attentuated total reflectance (HATR) sample accessory has been found to rapidly give good qualitative results for the extent of oxidation. The concentration of oxidation products has been determined and compared to the deposits formed for 12 thermally stressed fuels. No correlation was found between the extent of oxidation and deposition.

Thermal oxidation products from jet fuels will be formed in the presence of fuel and oxygen at elevated temperatures. Development of fuels that will not form solid residues depends on the development of a method to analyze the rate of oxidation of fuels. Gravimetric determination of fuel residues was imprecise and time consuming. Gas Chromatography - Mass Spectrometry of oxidation products yields a great deal of fundamental information but is too specific to be used as a rapid method for determining the rate of oxidation. Fourier Transform Infrared Spectrometry is non-specific and gives integrated signals for classes of oxidation products that will give rapid analytical results for rates of oxidation as well as the ability to study the effectiveness of chemical additives.

Jet fuel deposits, some of them supplied on their original support by Dr. Hazlett of the Naval Research Laboratory were examined by attenuated total reflection spectroscopy and by infrared Fourier transform emission spectroscopy for the purpose of finding a procedure suitable for in situ analysis. The infrared radiation emitted by samples at 50-65 C was adequate for qualitative analysis, which can readily be made quantitative by further work. Definite sharp peaks corresponding to aromatic materials were found. (Author).

Thermal oxidation products from jet fuels will be formed in the presence of fuel and oxygen at elevated temperatures. Development of fuels that will not form solid residues depends on the development of a method to analyze the rate of oxidation of fuels. Gravimetric determination of fuel residues was imprecise and time consuming. Gas Chromatography - Mass Spectrometry (GC-MS) of oxidation products yields a great deal of fundamental information but is too specific to be used as a rapid method for determining the rate of oxidation. Fourier Transform Infrared (FTIR) Spectrometry is non-specific and gives integrated signals for classes of oxidation products that will give rapid analytical results for rates of oxidation as well as the ability to study the effectiveness of chemical additives.