Iodine analysis of foodstuffs samples using epithermal instrumental neutron activation analysis

Abstract

Iodine is an essential element that has an important role in the proper growth and thyroid hormone functioning of humans. Iodine deficiency was correlated with the health status of human-caused by malnutrition. The analytical method to analyze the Iodine content on foodstuffs is limited because Iodine concentration exists in a level of a trace. 127I has a ratio of I 0 to s relatively high, and it is possible to obtain 128I (t1/2 = 24.5 minutes) using nuclear reaction with an epithermal neutron. Samples were collected at Magelang region, and it consists of foodstuffs that consumed by the citizen. All sample has been dried using Freeze dryer at-90 °C and 0.03 bar for 24-48 hours. After drying, the sample then pounded to get the form of granules smooth, about 100-150 mesh. About 40 to 130 mg of sample was weighed accurately on a clean micro vial of Polyethylene. Irradiation has been carried out at l5 MW reactor power using neutron epithermal for 45 seconds at the rabbit facility of GA. Siwabessy reactor. After cooling 5 to 10 minutes, the irradiated sample then counted for 300 seconds, and the gamma-ray spectra obtained emitted have been analyzed by Hyperlab software. Several standard reference materials of NIST have been used as analytical quality control. The experimental result shows that the Iodine has the Boron ratio, RB, and the Advantage factor, Fadv, equal to 2.4 and 21, respectively. Trace element of Iodine has been determined quantitatively on nine spices, seven types of meat, and 32 vegetables. The Iodine concentration on spices have average 1.57 ± 0.23 mg/kg with range value 0.38 mg/kg to 3.4 mg/kg. Iodine on vegetable have average of 2.00 ± 0.43 mg/kg with range value of 0.38 mg/kg to 7.30 mg/kg. Meanwhile, its concentration on meat has range 0.71 mg/kg to 2.16 mg/kg, with an average of 1.44 ± 0.28 mg/kg, lower than that on vegetables. Epithermal INAA is a reliable analytical technique for Iodine determination quantitatively.