Solvent extraction of europium with crown ether

Solvent extraction of europium (II) was carried out by using 15-crown 5-ether, 18-crown 6-ether and dicyclohexyl 18-crown 6-ether in the presence of a reducing agent. In three types of the crown ethers, dicyclohexyl 18-crown 6-ether was the most effective extractant for extraction of europium (II). As a diluent of the crown ether, α,α,alpha-trifluoro toluene, and the mixture of bromoform and carbon tetrabromide were used, and it was found that α,α,α-trifluoro toluene was a suitable diluent for extraction of europium (II) under reducing environment. Lithium salts of trichloro acetic acid, trifluoro acetic acid and trifluoro methane sulphonic acid were added into the aqueous phase as counter ions for europium (II), and it was found that the trifluoro methane sulphonic acid was the most effective counter ion. Metallic zinc fine powder and low melting point liquid alloy of Ga-In-Zn were used as reducing agents for Eu (III) to Eu (II), and it was found that the liquid Ga-In-Zn alloy was suitable reductant in the presence of L-Ascorbic acid. Under the suitable condition, high distribution ratio of Eu (9.0 × 10) and high separation factor of Eu/Gd (7.0 × 105) were obtained.