Interferences in the determination of lutetium using neutron activation analysis

We have investigated the severity of interferences in the determination of lutetium in neutron activation analysis. The preferred reaction makes use of the large radiative capture cross section of 2090 b for 176Lu(n,γ)177Lu, which emits a 208.4 keV gamma emission (t1/2 = 6.73 days). Activation of 176Lu simultaneously produces 177mLu, which also emits at 208.4 keV (t1/2 = 160.4 days). We found that these convolutions did not produce significant error in lutetium analysis for a sample of NIST 1633c, even for longer decay times used to reduce the 239Np interference at 209.8 keV.