Kinetic separation of heavy metal ions with new alkylated 8-quinolinols and its application to the environmental analysis

研究了新制备的烷基化8-喹啉醇(5-辛基氧基甲基-8-喹啉醇（HO_8Q）、2-甲基-5-辛基氧基甲基-8-喹啉醇（HMO_8Q）和5-（4-硝基苯基偶氮）-7-（4-乙基-1-甲基辛基）-8-喹啉醇（HNEQ）溶剂萃取Ga（III）、Mo（VI）、Zn（II）的方法。Ga（III）在弱酸性溶液中用HO_8Q在庚烷中萃取为Ga(O_8Q)_3 （Kex = 10^<3.2>）。另一方面，在HMO_8Q的情况下，萃取的配合物为Ga(OH)(MO_8Q)_2 （Kex = 10^<-4.2>）。以正庚烷为溶剂，用HO_8Q和HMO_8Q分别从含有氯离子的弱酸性溶液中提取Ga(III), Ga(O_8Q)_3和Ga(Cl)(MO_8Q)_2。用HO_8Q在庚烷中萃取Ga（III）的速率决定步骤应为Ga^<3+>和Ga(OH)^<2+>与HO_8Q和/或H_2O_8Q在水相中的竞争反应。氯仿的提取速度比庚烷的慢。在强酸溶液中用HO_8Q和HMO_8Q萃取Mo(VI)，并与Co（II）、Fe（III）、Cu（II）等金属离子分离。测定了MoO_2(O_8Q)_2和MoO_2(MO_8Q)_2的萃取常数分别为10^<17.7>和10^<14.9>。Pd（II）在氯仿中以HMO_8Q萃取得到Pd(MO_8Q)_2 （Kex = 10^<13.3>）。用0.3 M SCN^-溶液在pH 3.0条件下反提取氯仿中提取的配合物。萃取率对溶剂种类有显著的依赖性。因此，Pd（II）可以利用萃取速率的差异和反萃取的方法选择性地从其他金属离子中分离出来。研究了HNEQ对Zn（II）的协同萃取作用。用HNEQ可以将Zn（II）从Cd（II）中分离出来。这些结果有望应用于重金属离子的分离。

The solvent extraction of Ga(III), Mo(VI), Zn(II) with alkylated 8- quinolinols such as 5-octyloxymethyl-8-quinolinol(HO_8Q), 2-methyl-5- octyloxymethyl-8-quinolinol(HMO_8Q) and 5-(4-nitrophenylazo)-7-(4-ethyl-1-methyloctyl)-8-quinolinol(HNEQ), which were newly prepared, was investigated to develop highly selective separation systems.1. Ga(III) was extracted with HO_8Q in heptane from weakly acidic solution as Ga(O_8Q)_3 (Kex = 10^<3.2>). On the other hand, in a case of HMO_8Q, the extracted complex was to be Ga(OH)(MO_8Q)_2 (Kex = 10^<-4.2>). Ga(III) was extracted with HO_8Q and HMO_8Q in heptane from weakly acidic solution containing chloride ion as Ga(O_8Q)_3 and Ga(Cl)(MO_8Q)_2, respectively.2. The rate determining steps of the extraction of Ga(III) with HO_8Q in heptane should be the competitive reactions of Ga^<3+> and Ga(OH)^<2+> with HO_8Q and/or H_2O_8Q in an aqueous phase. The extraction in chloroform is very slow comared with that in heptane.3. Mo(VI) was extracted with HO_8Q and HMO_8Q in chloroform from very strong acidic solution and separated from other metal ions such as Co(II),Fe(III) and Cu(II). The extraction constants were determined to be 10^<17.7> for MoO_2(O_8Q)_2 and 10^<14.9> for MoO_2(MO_8Q)_2 respectively.4. Pd(II) was extracted with HMO_8Q in chloroform from hydrochloric acid as Pd(MO_8Q)_2 (Kex = 10^<13.3>). The extracted complex in chloroform was back extracted with 0.3 M SCN^- solution at pH 3.0.The extraction rate is remarkably dependent on the kinds of solvents. Consequently, Pd(II) can be selectively separated from other metal ions by using the difference in the extraction rate and by the procedure of the back extraction.5. The synergistic extraction of Zn(II) with HNEQ was extracted. Zn(II) was found to be separated from Cd(II) with HNEQ.These results will be expected to apply to the separation of heavy metal ions.