Accurate determination of selenium and iron in erythrocytes from Nigeria subjects using INAA

Abstract

Levels of two essential elements playing crucial roles in erythrocyte's structure and functions, iron and selenium, have been carefully determined in 36 erythrocyte samples drawn from two healthy Nigerian subjects. The samples were obtained at different times of the day and under varied dietary conditions over a three-week period. Normal variations that could occur in the levels of these elements within a given healthy individual could then be established. Analyses of the samples were carried out by Instrumental Neutron Activation Analysis using for each element, two different self-validating procedures. For selenium, the short-lived isotope 77nSe(t½ = 7.5s), and the long-lived isotope 75Se(t½ = 120d) were used; while for iron the two gamma lines at 1099.2 KeV and 1291.6 KeV from the reaction 58Fe(n,Y)50Fe were used. For each element, the results obtained from the two procedures were first compared, and then combined using the uncertainty in the individual assays as a weighting factor. Selenium levels in the erythrocytes of the two subjects were in the range of 167-317 ng/ml while iron levels varied from 782 – 888 ng/ml. Accuracy of these results laws further confirmed by concurrent analysis of two reference materials with similar matrix composition and analyte levels. Nigerian Journal of Physics Vol. 16(2) 2004: 105-109