Accurate determination of element traces in high purity reference materials by instrumental neutron activation analysis INAA

Instrumental neutron activation analysis INAA was applied for the trace element determination in some high purity candidate reference materials. By following an extensive calibration procedure, accuracy at the 1.2-6% level was obtained for trace determinations of Ta in Nb, iridium in Rh, and cobalt in Si. Platinum determination in Rh was considerably impaired by a concomitant eight-fold Ir-excess. Results agreed very well with results from other laboratories using neutron activation analysis and inductively coupled plasma-mass spectrometry (Ta), and X-ray fluorescence analysis, Rutherford-backscattering spectrometry and flame atomic absorption spectrometry (Co). The predominant advantages of INAA in this application are its high analytical sensitivity and its robustness against matrix effects and problems due to sample contamination.