Liquid-liquid extraction of cobalt(II) and manganese(II) with bis(2,4,4-trimethylpentyl)monothiophosphinic acid (Cyanex 302)

Liquid-liquid extraction of cobalt(II) and manganese(II) were carried out from sulfate solution with Cyanex 302 in toluene as the diluent. Cobalt(II) was quantitatively extracted at pH 7.0-7.5 in the presence of 1.0 M ammonium sulfate with 7.5x10 exp -3 M Cyanex 302 while the extraction of manganese(II) was quantitative at pH 8.5-9.5 in the presence of 0.1 M ammonium sulfate with 5x10 exp -3 M Cyanex 302. Cobalt(II) from the organic phase was stripped with 1.0 M hydrochloric acid while manganese(II) was stripped with 1.0 M sulfuric acid. Both metals were separated from complex mixtures of several metals. These methods were extended for the determination of cobalt and manganese in real samples.