Extraction Behavior of Palladium(II) with Chelate Ligands into Supercritical COィイD22ィエD2

The distribution behavior of HMO I D 26个D 2 Q between supercritical(SF)CO I D 22个D 2 and water and the extraction behavior of Ga(III)and Pd(II)with 2-methyl-8-quinolinol derivatives from an acidic solution into SF CO I D 22 I D 2 were investigated.Furthermore，the pH of an acidic solution contacting with SF I D 22个D 2was evaluated spectrophotometrically.Below pH3，the pH change of the aqueous solution contacting with SF CO I D 22个D 2 is negligibly small，but above pH3，the pH of the aqueous phase was levelled to about3.The distribution constant(K I D D2)of 2-methyl-5-hexyloxylhyl-8-quinolinol(HMO 26 D D_2)The K I D2D文件D2 value at 45°C and 20.4 MPa was about one tenth of the K I D 2D文件D2 value for heptane-water system.Ga(III)was extracted with HMO I D26文件D2Q into SFCO文件D22文件D2as Ga(OH)(MO D26文件D2Q)I D 22文件D 2.The extractability increases with an increment of the SF CO I D 22 I D 2 pressure.Ga(III)was completely separated from Al(II)with HMO I D26个D2Q at 45°C and 10MPa.The extractability of Pd(II)with HMQ from a weakly acidic solution into SF CO I D22个D2was remarkably affected by the Cl I D1-I D1 and H I D1+I D1 concentrations.Pd(II)should be extracted with HMQ as Pd(MQ)Y D22 II D2 from a weakly acidic solution。On the other hand，the Pd(II)complex extracted from the higher HCl concentration was H I D22文件D2 PdCl I D24文件D2.The proposed method can be potential technique for the selective separation of metals such as Pd(II)。

The distribution behavior of HMOィイD26ィエD2Q between supercritical (SF) COィイD22ィエD2 and water and the extraction behavior of Ga(III) and Pd(II) with 2-methyl-8-quinolinol derivatives from an acidic solution into SF COィイD22ィエD2 were investigated. Furthermore, the pH of an acidic solution contacting with SF COィイD22ィエD2 was evaluated spectrophotometrically.Below pH 3, the pH change of the aqueous solution contacting with SF COィイD22ィエD2 is negligibly small, but above pH 3, the pH of the aqueous phase was levelled to about 3.The distribution constant (KィイD2DィエD2) of 2-methyl-5-hexyloxymethyl-8-quinolinol (HMOィイD26ィエD2Q) between SF COィイD22ィエD2 and water increased with an increase in the SF COィイD22ィエD2 pressure. The KィイD2DィエD2 value at 45゜C and 20.4 MPa was about one tenth of the KィイD2DィエD2 value for heptane - water system.Ga(III) was extracted with HMOィイD26ィエD2Q into SFCOィイD22ィエD2 as Ga(OH)(MOィイD26ィエD2Q)ィイD22ィエD2. The extractability increases with an increment of the SF COィイD22ィエD2 pressure. Ga(III) was completely separated from Al(II) with HMOィイD26ィエD2Q at 45゜C and 10 MPa.The extractability of Pd(II) with HMQ from a weakly acidic solution into SF COィイD22ィエD2 was remarkably affected by the ClィイD1-ィエD1 and HィイD1+ィエD1 concentrations. Pd(II) should be extracted with HMQ as Pd(MQ)ィイD22ィエD2 from a weakly acidic solution. On the other hand, the Pd(II) complex extracted from the higher HCl concentration was HィイD22ィエD2PdClィイD24ィエD2.The proposed method can be potential technique for the selective separation of metals such as Pd(II).