INAA for the validation of chromium and copper determination in copper chromite by infrared spectrometry

Composite solid propellants have been used as fuel in the propulsion of rockets. Transition metal oxides such as copper chromite (CuCr2O4) are important catalysts added to the propellants to increase the combustion rates. The content of Cu in samples of copper chromite is normally determined by electrogravimetry and the content of Cr by volumetry. Considering that the content of Cu is important for the determination of the catalytic activity of copper chromite and that electrogravimetry and volumetry are very laborious and time consuming, Fourier transformed infrared spectroscopy (FT-IR) was implemented as an alternative fast method in the Aerospace Technical Center (CTA, Brazil). Here, instrumental neutron activation analysis (INAA), as an independent technique of high metrological level, was employed to validate Cr and Cu determination by FT-IR. The results from FT-IR were comparable to those determined by INAA. (author)