Synergistic Extraction Equilibrium of Gallium(III) with Di(2-ethylhexyl)phosphoric Acid and 8-Quinolinol Derivatives into Supercritical Carbon Dioxide
Synergistic Extraction Equilibrium of Gallium(III) with Di(2-ethylhexyl)phosphoric Acid and 8-Quinolinol Derivatives into Supercritical Carbon Dioxide
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DOI：
10.2116/analsci.29.127
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发表时间：
2013-01
影响因子：
1.6
通讯作者：
A. Ohashi;Natsumi Kawashima;Kazuaki Sato;Haeng-Boo Kim
中科院分区：
文献类型：
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作者：
A. Ohashi;Natsumi Kawashima;Kazuaki Sato;Haeng-Boo Kim
研究了5种8-羟基喹啉衍生物（HQ）对二（2-乙基己基）磷酸（D2 EHPA或HA）萃取镓（III）的协同效应。8-喹啉醇（Hq）、5-乙氧基甲基-8-喹啉醇（HO_2q）、5-己氧基甲基-8-喹啉醇（HO_6q）、5-（2，2，2-三氟乙氧基甲基）-8-喹啉醇（HFO_2q）和5-氯-8-喹啉醇（5-Cl-Hq）作为增效剂。所有HQ均观察到协同作用。协同效应的大小顺序为：Hq < HO_2q < HFO_2q < 5-Cl-Hq> HO_6q。协同作用的程度与HQ的分配常数和酸解离常数有关。研究了D2 EHPA和5-Cl-Hq在SC-CO_2介质中对Ga（III）的协同萃取平衡，结果表明，萃取配合物的组成为GaA_2Q·HA。SC-CO_2和正庚烷的协同萃取机理相同。根据实验结果计算了两种情况下的协同萃取平衡常数。
The synergistic effect of five 8-quinolinol derivatives (HQs) on the extraction of gallium(III) with di(2-ethylhexyl)-phosphoric acid (D2EHPA or HA) from weak nitric acid into supercritical carbon dioxide (SC-CO_2) was investigated. 8-Quinolinol (Hq), 5-ethoxymethyl-8-quinolinol (HO_2q), 5-hexyloxymethyl-8-quinolinol (HO_6q), 5-(2,2,2-trifluoroethoxymethyl)-8-quinolinol (HFO_2q), and 5-chloro-8-quinolinol (5-Cl-Hq) were used as synergists. Synergism was observed for all of the HQs. The synergistic effect increased in the following order: Hq < HO_2q < HFO_2q < 5-Cl-Hq ≈ HO_6q. The extent of synergism can be related to both the distribution constant and the acid dissociation constant of the HQ. The synergistic extraction equilibrium of gallium(III) with D2EHPA and 5-Cl-Hq into SC-CO_2 was investigated; the results suggest that the composition of the extracted complex is as GaA_2Q•HA. The synergistic extraction mechanism was the same for both SC-CO_2 and n -heptane. The synergistic extraction equilibrium constants in both cases were calculated based on the experimental results.