Instrumental Reactor Neutron Activation-Analysis Studies on 72 Elements in a Refined Hydrocarbon

Concentration measurements and determinations of upper limits to concentrations are obtained instrumentally by gamma-ray spectrometry following reactor neutron activation. The concentrations of identifiable spectral components are computed, as are also upper limits to the concentrations of those elements that made no observable contribution to the spectra. The upper limits are computed from the shape of an observed spectrum and from a knowledge of the yield and spectral shape of prominent radioactivities from each element under the conditions of irradiation. As an example of this analytical technique, upper limits obtained on a refined hydrocarbon were:

1.  1 element   < 1 ppb
2.  6 elements  < 10 ppb
3. 20 elements < 100 ppb
4. 42 elements < 1000 ppb

Identified components were sodium (0.5 ppm), aluminum (14 ppm), and zinc (39 ppm).