Reversed-Phase Column Extractive Separation of Gd(III) with Poly[dibenzo-18-crown-6]

A poly[dibenzo-18-crown-6] exhibits good chemical stability, reusability, and faster rate equilibrium for the separation of Gd(III). Both uptake and stripping of metal ions were rapid, indicating a better accessibility of the complexing sites. The proposed method has been applied for chromatographic separation of Gd(III) by using picric acid as medium and poly[dibenzo-18-crown-6] as stationary phase. The influences of picric acid concentration, different eluting agents, and so forth, were discussed and the optimum conditions were established. The breakthrough capacity of poly[dibenzo-18-crown-6] for Gd(III) was  mmolg−1 of crown polymer. The proposed method has been applied to sequential chromatographic separation of their binary and multicomponent mixtures. Gd(III) has been determined from real samples with good analytical reliability.