Distillation is normally used to remove more volatile impurities from uranium hexafluoride. Here this method of distillation was applied to natural uranium hexafluoride samples to pre concentrate those impurities which are leas volatile than UF 6. Mass spectra were obtained from "pre concentrated" samples using a quadrupole mass spectrometer and were compared with those of "original" samples. The mass spectra were found to be complex due to the formation of different UF6 daughter ions during ionization process which in some cases also interfere with the impurity peaks. After pre concentration process the fluorides of Cr, Ta. Ir, Rb, Ti, Si, Sr and Rh were identified. Many organic impurities were also found in the sample. 


M A ATTA ,AQIL KHAN ,A R FAROOQUI ,