The Neutron Activation Analysis of Mercury in Soil

Abstract

Abstract A radiochemical neutron activation procedure has been designed for the determination of mercury in soils. After the irradiation of 100 mg of soil it was decomposed with a hydrofluoric and perchloric acid mixture in a platinum crucible, and the mercury was separated radiochemically by solvent extraction from sulfuric acid·potassium iodide media into toluene, followed by precipitation as a sulfide. The radioactivity of 197Hg was measured by using a Ge(Li) detector. The chemical yield, as determined by atomic absorption spectrophotometry, was high enough, and the precision was satisfactory. The detection limit is estimated to be 1–2 ppb [(1–2)×10−10 g] by this method. The above procedure was applied to the determination of mercury in soils sampled in the Kumamoto and Minamata districts and in between.