Abstract:
Various types of instrumental neutron activation analysis (INAA) method
were developed for the determination of Iodine and 30 major, minor, and trace
elements in samples of Ghanaian foods. Most of the elements were analysed by
conventional INAA with anticoincidence counting. A number of INAA methods were evaluated for selenium and iodine determinations. The methods included:
conventional and Pseudo-Cyclic TNAA (PCINAA) with Compton suppression
gamma-ray spectrometry for selenium. The INAA methods developed for iodine
determinations were Conventional Flux and Epithermal INAA (EINAA) using
Compton suppression gamma-ray spectrometry. The relative method of
standardization was used for quantification of all the elements. Additionally,
quantification 01' iodine and some selected elements was carried out using ko-
NAA standardisation method. The Nisle unified formulation was investigated for
the ko-NAA method and compared with the well known
Hogdahl convention and Westcott formalism.
Precision and accuracy were evaluated through the analysis of standard
reference materials (SRMs). The measured values were found to be in good
agreement with the certified values; generally, within ± I0%. Detection limits
were calculated and found to vary from 1.0 ng.kg·\ for antimony and gold to 400
mg.kg-1 for sulphur. The overall uncertainty associated with the measurement of
Iodine using both the relative and the ko methods of standardization were
evaluated. In general, most of the Ghanaian food items were found to contain the
required concentration of iodine and other elements of nut6tiol1al importance.
