%0 Journal Article %T Reversed-Phase Column Extractive Separation of Gd(III) with Poly[dibenzo-18-crown-6] %A K. R. Mahanwar %A S. R. Sabale %A R. B. Kadam %A B. S. Mohite %J International Journal of Inorganic Chemistry %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/515196 %X 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. 1. Introduction In recent years the separation chemistry of rare earth elements (REEs) continues to receive a growing interest. The major reasons for this stems from the importance of rare earths not only in industrial application but also in energy generation activities and environmental mitigation. Gadolinium is useful in nuclear techniques, in fuel element fabrication and in ceramic industries and as control rod and as refractory material [1, 2]. In view of all the above applications the separation and purification of Gd(III) are important. The main focus of the extensive research on chelating resins is the preparation of functionalized polymer that can provide more flexible working conditions together with good stability, selectivity, high concentrating ability, high capacity of metal ions, and simpler operation [3¨C6]. Crown ethers are effective extractants due to their ability to form stable complexes with metal ions. In recent years extraction chromatography has emerged as a versatile and effective method for analytical and preparative scale metal ion separation [7¨C9]. Also crown ethers are used as sorbents in chromatographic techniques [10¨C17] like TLC, extraction chromatography-liquid chromatography on columns, and gas chromatography for actinides and lanthanides. By using poly[dibenzo-18-crown-6] we have reported the sorption behavior and separation study of alkali and alkaline earth metal in various mediums like ascorbic acid, sodium nitrate, hydrochloric acid, and L-arginine [18¨C23]. To our knowledge no successful attempts were reported in the literature for the separation of Gd(III) using poly[dibenzo-18-crown-6] in picric acid media and column chromatography. The present paper describes a simple and %U http://www.hindawi.com/journals/ijic/2012/515196/