三烷基氧磷络合萃取邻氨基苯酚的研究

络合萃取技术对极性有机物稀溶液的分离具有高效性和高选择性，然而对同时具有Lewis酸性和Lewis碱性两种官能团化合物的络合萃取研究得相对较少。为了探讨该技术对两性有机化合物萃取规律，今以三烷基氧磷（TRPO）为萃取剂，邻氨基苯酚为萃取溶质，研究了稀释剂种类、溶液pH值以及溶质浓度等因素对邻氨基苯酚稀溶液萃取平衡分配比的影响；根据可逆络合萃取的基本理论，提出了同时考虑萃取剂络合萃取作用和稀释剂物理萃取作用的分配比的表达式。并通过参数寻优求出邻氨基苯酚的物理萃取分配常数m和表观化学反应萃取平衡常数K。结果表明，邻氨基苯酚主要通过氢键缔合与OAP的中性分子发生络合反应而萃入有机相，其在惰性稀释剂煤油中的分配比大于其在极性稀释剂正辛醇中的分配比。

Complexation Extraction of O-Aminophenol with TRPO

Complexation extraction, a process based on reversible chemical complexation, can be used to separate the polar organic solutes from dilute solution with high capacity and selectivity. But the complexation extraction of amphoteric organic compounds having two different kinds of functional groups, Lewis acid and Lewis base, has been studied rarely. In order to study the complexation extraction of the amphoteric organic compound, the o-aminophenol (OAP) was used as the amphoteric extractive and the trialkylphosphine oxide (TRPO) was used as extractant with the kerosene or n-octanol as diluent. Some key factors affecting the complexation extraction of amphoteric OAP from its dilute solution, such as the initial concentration of OAP in the solution, the pH value of the solution, the concentration of TRPO extractant and the kind of diluent used, were studied experimentally. An expression of equilibrium distribution ratio of OAP including chemical complexation and physical extraction was proposed. Through the optimization of the parameters of the expression, the OAP distribution constant of physical extraction m and the apparent equilibrium constant of chemical complexation reaction k were gained. The results show that the complexation extraction of OAP into organic phase depends mainly on chemical complexation between TRPO and the neutral molecules of OAP through the association of the hydrogen-bond, and when the kerosene is used as diluent, the OAP extraction ability of TRPO is higher than that of when the diluent n-octanol is used.