Corrections for carbon and oxygen interference in the 14-MeV neutron activation determination of nitrogen

Abstract

Reactions in the carbon and oxygen atoms of sample matrix can lead to errors in the 14 MeV neutron activation determination of nitrogen based on the¹⁴N(n, 2n) reaction, particularly as a consequence of proton-induced reactions leading to¹³N formation in samples of an organic nature. In this study, the extent of such interferences have been evaluated by measuring the “apparent N” contribution when a series of alcohols and a water sample were irradiated with 14 MeV neutrons from a Texas-Nuclear neutron generator under the same conditions used for trace N determination and contributions amounting to from 0.1 to 1% “apparent N” content observed (and corrected for). Owing to neutron flux in stabilities and assymetries, flux monitoring was done with aluminum foils on either side of the samples for N analysis, and which were counted for²⁴Na. Two samples of foodstuff were analyzed correction for C and O interference, agreed with conventional analysis within ±10%.