Simultaneous Determination of Cadmium and Some Other Elements in Unpolished Rice by Neutron Activation Analysis

Abstract

Simultaneous determination of cadmium and some other elements in unpolished rice by non-destructive and destructive activation analysis using a high resolution Ge (Li) detector was investigated.
The samples were irradiated in a thermal neutron flux of 1-2×1012n⋅cm^-2⋅sec^-1and the irradiation times were 10 hours for long life nuclides and 10 minutes for short life nuclides, respectively. In the destructive method, column isotopic exchange technique by sodium bromide and potassium bromide mixture was tried for the removal of²⁴Na, ⁴²K and⁸²Br which were the most interfering elements in activation analysis of unpolished rice. It allowed us to remove²⁴Na, ⁴²K and almost all⁸²Br simultaneously.
In the analysis of unpolished rice samples produced around Fuchu City, Tokyo, Cd, Cr, Zn, Sb, Mn, Na, K, Cl and Br were determined by non-destructive method and Cu, As and low content of Cd were detected only by the above-mentioned destructive method. From these results, it was found that the several samples are polluted with Cd and the other elements such as Sb, Cr and Br.