The Nigerian Research Reactor-1 was employed in the analysis of iodine in local food samples at an operating flux of ？ncm？2？s？1. Preconcentration neutron activation analysis (PCNAA) was compared against the most common spectroscopic (Sandell-Kolthoff reaction) technique, giving a concentration range of 0.295 to 2.960？mg/Kg and 0.264 to 2.725？mg/Kg, respectively, with an average percentage deviation of 11.34% and a positive correlation between the methods at 0.89. PCNAA and Sandell-Kolthoff spectroscopy of NIST 1548a reported values of ？mg/Kg and with Student’s t-test score of 1 and 0.95 and percentage standard deviation of 0 and 1.12%, respectively. 1. Introduction Iodine is an essential component of the thyroid hormones: thyroxine (T4) and triiodothyronine (T3), comprising 65 and 59 percent of their respective weights [1]. The thyroid hormones T4 and T3 regulate many key biochemical reactions, particularly protein synthesis and enzymatic activity. Major target organs are the developing brain, muscle, heart, pituitary, and kidney. Without sufficient iodine, the body is unable to synthesize the thyroid hormones, and because they regulate metabolism in every cell of the body and play a role in virtually all physiological functions, iodine deficiency can have a devastating impact on health and well-being summarily termed iodine deficiency disorders (IDD). IDD is a major cause of retardation in children and was one of the contributing factors to high infant mortality [2]. Thyroid hormones, and therefore iodine, are essential for mammalian life. The Nigerian Research Reactor-1 (NIRR-1) is the first in the country and its primary objective is to uplift the socioeconomic life of Nigerian citizen through effective utilization and research activities. It is meant to serve all categories in need of nuclear analytical and other related services. Irradiation and counting regimes for over 30 elements in both biological and geological matrices, including the essential elements Fe, Cr, Co, Cu, Mn, and Zn have been standardized [3]. Recently, standard addition technique was employed to determine Selenium in cereals [4]. Accurate determination of iodine and in particular in biological matrix has always been difficult due to its low concentration and the inherent volatility of molecular iodine through sublimation at room temperature. However, iodine concentrations in biological matrix have been analyzed using a variety of techniques including spectroscopy [5–7], inductively coupled mass spectrometry [8–10], and ENAA [11–13] with the neutron activation analysis and mass
References
[1]
O. M. Ahmed, A. W. El-Gareib, A. M. El-bakry, S. M. Abd El-Tawab, and R. G. Ahmed, “Thyroid hormones states and brain development interactions,” International Journal of Developmental Neuroscience, vol. 26, no. 2, pp. 147–209, 2008.
[2]
Iodine deficiency, International Council for the Control of Iodine Deficiency Disorders, 2011, http://www.iccidd.org/.
[3]
S. A. Jonah, I. M. Umar, M. O. A. Oladipo, G. I. Balogun, and D. J. Adeyemo, “Standardization of NIRR-1 irradiation and counting facilities for instrumental neutron activation analysis,” Applied Radiation and Isotopes, vol. 64, no. 7, pp. 818–822, 2006.
[4]
Y. A. Yamusa, Y. A. Ahmed, Y. Musa, S. A. Kasim, M. Tukur, and S. Bilal, “Multi-elemental analysis of local millet and wheat by instrumental neutron activation analysis using NIRR-1 facility,” International Journal of Multidisciplinary Sciences and Engineering, vol. 4, no. 7, pp. 9–13, 2013.
[5]
O. M. Trokhimenko and V. N. Zaitsev, “Kinetic determination of iodide by the Sandell-Kolthoff reaction using diphenylamine-4-sulfonic acid,” Journal of Analytical Chemistry, vol. 59, no. 5, pp. 491–494, 2004.
[6]
R. Gurkan, N. Bicer, M. H. Ozkan, and M. Akcay, “Determination of trace amounts of iodide by an inhibition kinetic spectrophotometric method,” Turkish Journal of Chemistry, vol. 28, pp. 181–191, 2004.
[7]
M. R. Shishehbore, A. Sheibani, and R. Jokar, “Kinetic spectrophotometric determination of trace amounts of iodide in food samples,” Analytical Sciences, vol. 26, no. 4, pp. 497–501, 2010.
[8]
J. W. Gramlich and T. J. Murphy, “Determination of trace level iodine in biological and botanical reference materials by isotope dilution mass spectrometry,” Journal of Research of the National Institute of Standards and Technology, vol. 94, no. 4, pp. 215–220, 1989.
[9]
P. A. Fecher, I. Goldmann, and A. Nagengast, “Determination of iodine in food samples by inductively coupled plasma mass spectrometry after alkaline extraction,” Journal of Analytical Atomic Spectrometry, vol. 13, no. 9, pp. 977–982, 1998.
[10]
J. H. Lee, O. Ji, M. Song et al., “Determination of urinary iodine concentration by inductively coupled plasma-mass spectrometry in thyroid cancer patients on low-iodine diet,” Korean Journal of Laboratory Medicine, vol. 30, no. 4, pp. 351–356, 2010.
[11]
T. Sato and T. Kato, “Estimates of iodine in biological materials by epithermal neutron activation analysis,” Journal of Radioanalytical Chemistry, vol. 68, no. 1-2, pp. 175–180, 1982.
[12]
T. A. Nichols, J. S. Morris, V. L. Spate et al., “Longitudinal study of iodine in market milk and infant formula via epiboron neutron activation analysis,” Journal of Radioanalytical and Nuclear Chemistry, vol. 236, no. 1-2, pp. 65–69, 1998.
[13]
J. Ku？era, G. V. Iyengar, Z. ？anda, and R. M. Parr, “Determination of iodine in Asian diets by epithermal and radiochemical neutron activation analysis,” Journal of Radioanalytical and Nuclear Chemistry, vol. 259, no. 1, pp. 505–509, 2004.
[14]
W. B. Stroube Jr., W. C. Cunningham, and G. J. Lutz, “Analysis of foods for iodine by epithermal neutron activation analysis,” Journal of Radioanalytical and Nuclear Chemistry, vol. 112, no. 2, pp. 341–346, 1987.
[15]
V. A. Maihara, P. L. C. Moura, D. I. T. Fávaro, and M. B. A. Vasconcellos, “Assessment of iodine content in Brazilian duplicate portion diets and in table salt,” Journal of Radioanalytical and Nuclear Chemistry, vol. 278, no. 2, pp. 391–393, 2008.
[16]
A. Chatt and R. R. Rao, “Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine,” Analytical Chemistry, vol. 63, no. 13, pp. 1298–1303, 1991.
[17]
E. B. Sandell and I. M. Kolthoff, “Micro determination of iodine by a catalytic method,” Mikrochimica Acta, vol. 1, no. 1, pp. 9–25, 1937.
[18]
J. Tyndall, V. Okaye, M. Ameh et al., “Determination of iodide content of table salts in Nigeria,” European Chemical Bulletin, vol. 2, no. 6, pp. 324–327, 2013.
[19]
P. W. Fischer, M. R. L'Abbé, and A. Giroux, “Colorimetric determination of total iodine in foods by iodide-catalyzed reduction of Ce+4.,” Journal - Association of Official Analytical Chemists, vol. 69, no. 4, pp. 687–689, 1986.
[20]
C. O. Ujowundu, F. N. Kalu, R. N. Nwaoguikpe, K. O. Igwe, R. I. Okechukwu, and T. I. N. Ezejiofor, “Salt iodization and thyroid function of pregnant women in early pregnancy in Owerri-southeast Nigeria,” International Research Journal of Biochemistry and Bioinformatics, vol. 1, no. 10, pp. 248–256, 2011.
