Spectrophotometry Determination of Uranium as Mixed Ligand Chelate of N, N'-Bis(o-hydroxyphenyl)ethylenediimine

Abstract

Spectrophotometric determination of uranyl chelate, extracted by organic solvent, has been investigated. In an aqueous alkaline buffered solution (pH: 12.0~12.5), uranyl ion reacts with N, N'-bis(o-hydroxyphenyI)ethyIenediimine (HPEI=H2hpei) to form 1 : 1 chelate whose absorption maximum appears at 565 nm. However, in the presence of enough zephiramine (quarternary ammonium), uranyl ion forms a uranyl hpei chelate of different composition which shows absorption maximum at 645 nm, a ratio of U to hpei is 1:2. The latter chelate is extracted by a certain organic solvent, e.g., 1, 1, 2, 2-tetrachloroethane (TCE) or 1, 2-dichloro-ethane. U: hpei: Z of the extracted chelate was determined to be 1: 2: 1. The spectrophotometric determination of uranium is possible in the range of 0~120μg in an aqueous solution and 0~50 μg in an organic solvent. The molar absorption coefficients of the mixed ligand chelate are 1.44×104 and 1.41×104 in an aqueous solution and in TCE, respectively. © 1976, The Chemical Society of Japan. All rights reserved.