【作者】 逯洋；

【导师】 闫永胜；

【作者基本信息】 江苏大学 ， 清洁能源与环境保护， 2014， 博士

【摘要】 双水相萃取技术作为一种新型的绿色分离/富集技术,具有简单、省时、高效和绿色无污染等优点,已被应用于金属离子的定量分离萃取、生物活性物质的分离纯化以及天然产物的提取等领域。目前的双水相体系主要包括聚合物-聚合物双水相体系、聚合物-盐双水相体系、离子液体-盐双水相体系和小分子有机溶剂-盐双水相体系,但由于有机溶剂易挥发不稳定、离子液体成本较高和两种聚合物体系的粘度较大等问题,影响了这三种双水相体系在工业规模化生产中的应用。而聚合物-盐双水相体系用盐代替聚合物-聚合物双水相体系中的一种聚合物作为成相物质,在降低体系粘度和生产成本的同时,保留了聚合物生物相容性好的优势,被广泛应用于生物活性物质、天然产物及抗生素的分离纯化,具有较高的开发价值和广阔的应用前景。双水相体系相平衡理论和液-液相平衡性质的研究是支撑双水相体系发展的理论基石,但目前的研究还不能完全清楚地从理论上解释双水相体系的形成机理以及预测物质在两相间的分配行为,这也在一定程度上限制了双水相体系的应用。因此,随着双水相体系研究的进一步发展,迫切需要相应的热力学理论做为指导工具。抗生素作为生物学和医学发展史上的重要里程碑,对人类和动物疾病的预防与治疗起到了极其重要的促进作用。随着抗生素在临床医学、养殖业以及食品加工业的大量使用,动物性食品药物残留和抗生素环境污染问题引起了人们的广泛关注。由于食品和环境样品的基质成分复杂且干扰物质多,其中所残留的抗生素又通常是痕量或超痕量存在,单一使用现有的分析检测方法已经不能满足其检测要求。因此,建立一种简单、快速、有效的分离/富集预处理技术已经成为抗生素残留检测工作的关键。本课题旨在构建聚氧乙烯月桂醚(Brij35)-盐双水相萃取体系,并将其应用于分离/富集环境和食品中的抗生素残留；深入分析体系中成相盐的分相能力,探索分相过程的热力学行为,为Brij35-盐双水相体系的应用研究提供坚实的理论基础；探讨各影响因素对目标抗生素在体系中选择性分配行为的影响机理,确立显著影响因素,构建最优实验条件,为食品和环境样品中其它污染物的分离／富集提供新的技术手段和科学依据。具体研究内容如下：(1)实验测定了14组Brij35-无机盐/有机盐双水相体系在不同温度下的双节线数据并对实验数据进行了关联拟合,针对具体的双水相体系确定了双节线拟合方程。通过实验测定和计算两种方式获得了Brij35-无机盐／有机盐双水相体系在不同温度下的液-液相平衡数据,并对数据进行了关联拟合,取得了令人满意的拟合效果。(2)通过计算Brij35-盐双水相体系的有效排除体积和绘制体系的双节线相图以及阴、阳离子的吉布斯自由能,深入探讨了双水相体系中成相盐的盐析能力和温度对体系成相条件的影响,得到如下结论：①当盐的阳(或阴)离子相同时,阴(或阳)离子的化合价越高,盐的盐析能力越强；②当盐的阳离子相同时,阴离子的吉布斯自由能的绝对值越大,盐的有效排除体积越大,盐的盐析能力越强,即：一价阴离子(OH-<C6H11O7-)<二价阴离子(C2O42-<C4H4O62-<CO32-<HPO42-)<三价阴离子(C6H5O73-<PO43-)；③当盐的阴离子相同时,阳离子的吉布斯自由能的绝对值越大,有效排除体积越大,盐的盐析能力越强,即：NH4+<K+<Na+、一价阳离子(Li+)<二价阳离子(Zn2+<Mg2+)。④随着温度的升高,体系的有效排除体积增大,双节线向坐标原点移动,双相区域扩大,单相区域缩小,体系的成相能力增强；⑤随着温度的升高,Brij35的疏水性增强,体系的成相能力增强,系线斜率的绝对值增大。(3)根据Brij35-盐双水相体系中电解质与高分子同时存在并且相互影响的特点,将超额吉布斯自由能表述为长程静电作用力、短程相互作用力和组合作用力三者之和,并使用PDH方程、改进的NRTL方程和Flory-Huggins方程分别表述三种作用力,对Brij35-盐双水相体系在温度T=(15、25和35)℃下的液-液相平衡数据进行了关联拟合。利用工作方程和关联拟合得到的模型参数,对Brij35-盐双水相体系中未参加关联计算的液-液相平衡数据进行预测,并将预测结果与实验测得结果进行比较,得到了令人满意的预测效果。(4)以环境和食品中的抗生素残留为目标,成功构建了Brij35-无机盐/有机盐双水相萃取体系与高效液相色谱法相结合的绿色分离／富集／检测技术：①构建Brij35-NaH2PO4双水相萃取体系用于分离、富集环境水样和水产品中残留的痕量氯霉素,通过响应曲面实验设计得出结论：NaH2PO4的浓度、Brij35的浓度、体系的温度和pH值等因素与萃取效率不是简单的线性关系,影响因素之间的相互作用对萃取效率也有一定的影响,其中NaH2PO4的浓度和体系的温度对萃取效率的影响极显著。②构建Brij35-(NH4)2SO4双水相萃取体系,并将其应用于土壤和蜂产品中甲砜霉素的分离与富集,对影响萃取效率和富集倍数的各因素进行了讨论,确定最佳萃取条件。③基于环境友好理念,构建了Brij35-有机盐(Na2C4H4O6)双水相萃取分离体系,并与高效液相色谱检测联用,成功实现了对动物副产品和环境水样中残留的磺胺嘧啶和磺胺二甲基嘧啶的同步分离、检测。基于单因素实验和正交实验分析,探讨了各因素对萃取效率和富集倍数的影响强度,确立了最优实验条件。更多还原

【Abstract】 Aqueous two phase extration is a new and green separation and enrichment technology, and it has some advantages, such as simple, timesaving, efficient, green and eco-friendly, and it has been applied to the quantitative separation and extraction of metal ions, separation and purification of bioactivator and extraction of natural product. The existent aqueous two-phase system included polymer-polymer aqueous two-phase system, polymer-salt aqueous two-phase system, ionic liquid-salt aqueous two-phase system and micromolecule organic solvent-salt aqueous two-phase system. Because organic solvent is volatile and instable, the price of ionic liquid is higher and the viscosity of system containing two polymer is larger, the application of these three types of aqueous two-phase systems in large-scale industrial production was affected. One polymer of polymer-polymer aqueous two-phase system was replaced by salt, and it is polymer-salt aqueous two-phase system. The cost and viscosity of polymer-salt aqueous two-phase system is cheaper, and it has the advantage of good biocompatibility. It is applied in the separation and enrichment of bioactivator, natural product and antibiotic, and has high-exploited value and broad prospects on its application. The study of phase equilibrium theory and nature of aqueous two-phase system is the theoretical cornerstone to support its development, but the present study didn’t explain the formation mechanism of aqueous two-phase system and it did not predict its distribution mechanism of the matter in two phases, which restrict its development. As the guidance of its development, the thermodynamic theory of aqueous two-phase system is imperative for the further advances in the studies of aqueous two-phase system.As the significant milestone of the development history of biology and medical science, antibiotics played a great important role to promote the prevention and treatment in the disease of human and animal. With using antibiotics extensively in clinical medicine, breeding industry and food processing industry, the drug residue in food of animal originated the problem and the antibiotics environment pollution has attracted the people’s attention. The matrix elements of food and environment samples are complex and the samples contain many interfering substance, meanwhile, the residual antibiotics in real sample is trace or ultratrace. It is difficult to determine the trace of antibiotics only by using the available analysis and detection methods. Therefore, it is crucial to build up a simple, fast and effective pretreatment technology for separation and enrichment in order to determine the residual antibiotics.The aim of this paper is to establish the Brij35-salt aqueous two-phase extraction system, which will be applied to the separation and enrichment pretreatment of residual antibiotics in food and environment samples. The forming-phase abilities of salts and the thermodynamics behavior in forming-phase will be studied, which is the massy theoretical basis of the applied research of Brij35-salt aqueous two-phase system. The influence mechanism of the effect of influencing factors on the selective distribution behavior in system had been investigated, and the obvious significance and optimal experiment condition had been determined. These provided a new technological means and scientific basis for the separation and enrichment of other pollutant in food and environment samples. The concrete research content goes as follows:(1) The binodal curves data of14groups of Brij35-inorganic salt/organic salt aqueous two-phase system at different temperatures were determined, and the experimental data were fit by the experience equation. The optimal fitting equation was determined for each aqueous two-phase system. The liquid-liquid phase equilibrium data of14groups of Brij35-inorganic salt/organic salt aqueous two-phase system at different temperatures were determined by experiment or computer. The data were correlated and obtained the satisfactory fitting results.(2) The salting-out abilities of salts and the effect of temperature on the forming-phase conditions were deeply discussed through the effective exclude value of Brij35-salt aqueous two-phase system, the binodal curves diagram and the gibbs free energy of anion and cation. The conclusions can be drawn as follows:①The salting-out ability of salt with the same cation (or anion) is much stronger when the valence of anion (or cation) is higher.②When the cation of salt is same, its salting-out ability strengthened with the increase in effective exclude value and gibbs free energy of anion, namely, monovalent anion (OH-<C6H11O7-)<divalent anion (C2O42-<C4H4O62-<CO32-<HPO42+-)<trivalent (C6H5O73-<PO43-).③When the anion of salt is same, its salting-out ability strengthened with the increase in effective exclude value and gibbs free energy of cation, namely, NH4<K+<Na+, monovalent cation (Li+)<divalent cation (Zn2+<Mg2+).④Rising temperature leads to the increase in the value of effective exclude value, which indicated that the forming-phase abilities of ATPS enhanced, namely, the binodal curve moved towards the origin of coordinate, two-phase area expaned and the single phase area reduced.⑤The hydrophobicity of Brij35strengthened with the increase in temperature, which resulted in that the forming-phase ability of system enhanced and the absolute value of slope of tie-line rised.(3) The excess gibbs free energy of Brij35-salt aqueous two-phase system was represented by the sum of three components of long-range interaction contribution, short-range interaction contribution and combinatorial contribution because the electrolyte and polymer coexisted in aqueous two-phase system and each component influences each other. These three contributions were respectively represented by PDH equation, modified NRTL equation and Flory-Huggins equation, and the liquid-liquid phase equilibrium data were correlated by the thermodynamic work equation. The liquid-liquid phase equilibrium data that were not used in the correlation was obtained by the prediction of the thermodynamic work equation and its model parameter. The prediction data were compared with the experiment data, and it gave a satisfactory results.(4) The green separation/enrichment/detection technique coupling Brij35-organic salt/inorganic salt aqueous two-phase extraction system with high performance liquid chromatography was built in order to trace the residual antibiotics in food and environment sample.①The Brij35-NaH2PO4aqueous two-phase extraction system was constructed and used in the separation and enrichment of residual trace chloramphenicol in aquatic products and environment water samples. The response surface method was used in designing the experiment scheme and analyzing the experiment data, and it supports the following conclusions that the relationship between extraction efficiency and the experiment influence factors includes the concentration of NaH2PO4, the concentration of Brij35, and the temperature and pH of system is not linear; the interaction of influence factors also affected the extraction efficiency; the influence of the concentration of NaH2PO4and its temperature on extraction efficiency is significant.②The Brij35-(NH4)2SO4aqueous two-phase extraction system was applied to separate and enrich residual thiamphenicol in soil and bee products, the effect of experiment influence factors on the extraction efficiency and enrichment factor was discussed, the linear relation of extraction efficiency and influence factors was verified by the response surface method, and the optimal experiment conditions was found.③Based on the concept of environment friendly, the Brij35-organic salt (Na2C4H4O6) aqueous two-phase extraction system was coupled with high performance liquid chromatography, and this system was successfully applied to simultaneously separate and determine residual sulfadiazine and sulfamethazine in animal by-products and environment water samples. The influence intension of experiment factors on extraction efficiency and enrichment factor was studied and the optimal experiment condition was established.更多还原