Studies on extraction of Cu(II), Ga(III), In(III) and Tl(III) with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one: Separation and spectrophotometric determination of copper and gallium

Abstract

The extraction of Cu(II), Ga(III), In(III) and Tl(III) with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HPMBzP) from aqueous solutions has been investigated. The mechanism of extraction and the composition of the species extracted has been determined. The effect of equilibration time, various organic solvents and salting-out agents on the extraction of copper and gallium has also been investigated. The green Cu(PMBzP) 2 chelate has absorption maxima at 298 and 670 nm, and PMBzP has maximum absorbance at 290 nm. A new and sensitive spectrophotometric method for copper has been devised, based on the absorbance at 670 nm. The presence of excess of reagent does not interfere and no special treatment is necessary to destroy it. The proposed method has some advantages and has been applied for the determination of copper in various soil samples. Gallium has been separated from indium, thallium, copper, iron and many other elements. The recovery of gallium and copper was 100 ± 0.2%.