Determination of traces of carbon, nitrogen and oxygen in molybdenum and tungsten

The determination of carbon and nitrogen in molybdenum and of carbon, nitrogen and oxygen in tungsten, is described. The analytical techniques applied were charged-particle activation (carbon, nitrogen and oxygen), photon activation (carbon and oxygen), combustion (carbon) and vacuum-fusion extraction (nitrogen and oxygen). Chemical methods yielded upper limits in the 2-5 mug/g range. Activation analysis yielded 100 and 8 ng/g for carbon in molybdenum and tungsten respectively, 500 and 74 ng/g for nitrogen in molybdenum and tungsten respectively and 70 ng/g for oxygen in tungsten. The results obtained by charged-particle and photon activation agreed satisfactorily.