含氮杂环化合物萃取分离三价锕系与镧系元素

乏燃料后处理中的三价锕系和镧系元素分离是“分离-嬗变”过程的主要环节,对于建立先进核燃料循环具有重要意义。然而,三价锕系和镧系元素结构与性质非常相似,实现二者的分离一直都是分离科学研究领域的难题。溶剂萃取法是三价锕系和镧系元素分离的基本方法之一,而运用含硫、氮等软配位原子的萃取剂则是实现分离的关键。在众多的萃取剂中,含氮杂环化合物因其优良的萃取分离能力,同时符合CHON原则而利于实现废物最小化,近年来引起了广泛的研究兴趣。本文综述了国内外研究报道的典型含氮杂环类三价锕系和镧系元素分离萃取剂,包括三联吡啶、TPTZ、BTP、BTBP以及以TPEN为代表的氮杂环取代胺类萃取剂,对其分离能力、稳定性等性能进行了比较,对萃取机理以及影响其萃取能力的因素等亦进行了说明,并对萃取剂的后续设计、改进提出了参考性建议。     

酰胺类萃取剂萃取分离铕的研究进展

酰胺类萃取剂容易合成,热稳定性好,能完全燃烧,对环境友好等一系列优点,已广泛的用来从核燃料的后循环中萃取分离镧系元素和锕系元素。论述了使用不同类型的酰胺类萃取剂萃取及其分离铕的研究,重点讨论了丙二酰胺类和丁二酰胺萃取剂、酰胺莢醚类萃取剂、吡啶二甲酰胺类萃取剂、乙酰胺基胺类萃取剂萃取分离铕的最新研究成果,同时对这几类催化剂萃取铕的萃取效果进行了比较和讨论。     

聚乙二醇双水相萃取光度法测定铼

研究了聚乙二醇双水相体系中,金属离子络合物及萃取剂的光谱行为,研究了酸度、缓冲溶液用量、盐用量、萃取剂用量及表面活性剂对萃取铼的影响,并通过控制一定条件,可实现了混合离子的分离。     

酮洛芬对映体的双相识别手性萃取分离

研究了酮洛芬在溶有酒石酸酯的有机相和β-环糊精衍生物水相萃取体系中的分配行为;考察了有机溶剂、酒石酸酯、环糊精衍生物的种类、萃取剂浓度和pH等因素对分离效果的影响。结果表明,β-环糊精衍生物优先识别S-对映体而不是R-对映体,但L-酒石酸酯的识别能力刚好相反;1,2-二氯乙烷作为有机溶剂,三甲基-β-环糊精和L-酒石酸异丁酯做手性萃取剂是最好的选择;萃取剂的浓度和pH对分离效果有明显影响;当三甲基-β-环糊精和L-酒石酸异丁酯的浓度分别为0.1mol/L和0.2mol/L、水相pH=2.5时,分离效果最好。     

t-BAMBP萃取法分离提取高钾卤水中铷

为解决盐湖卤水中的铷与大量的性质极为相近的碱金属元素钾、钠、锂、铯共存给分离带来的困难,以t-BAMBP为萃取剂,萃取分离了高钾卤水中铷钾,考察了稀释剂种类、萃取剂浓度、碱度、相比、时间等相关因素对分离的影响。结果表明,选定二甲苯体系,1 mol/Lt-BAMBP,碱度1 mol/L NaOH,相比3/1,萃取时间2 min等条件下获得纯度达99.8%RbCl。铷萃取率97.0%,反萃取率98.4%,总回收率为95.5%。     

HEHEHP-HCl-NaAC体系萃取铥的机制研究

针对工业上广泛应用的氨水皂化HEHEHP[2-乙基己基磷酸单乙基己基脂]萃取剂分离稀土元素产生含有很高浓度NH+4的废水,对环境污染严重的问题,通过在稀土氯化物溶液中加入配合剂醋酸钠(CH3COONa),采用非皂化的HEHEHP萃取剂萃取重稀土元素Tm。研究了该体系中水相酸度、有机相浓度、乙酸钠浓度等因素对Tm3+分配比的影响。结果表明:HEHEHP-HCl-Na AC体系对Tm3+萃取过程遵循阳离子交换机制;萃取液中形成的乙酸-乙酸盐缓冲溶液能够维持萃取水相酸度恒定,萃取过程中有机相不再需要皂化,有效避免HEHEHP皂化产生含NH+4废水污染环境的问题。     

采用超临界CO2萃取技术提取废次烟叶中的茄尼醇

采用超临界CO2萃取技术提取废次烟叶中的有效成分茄尼醇,以乙醇为夹带剂,研究了萃取压力、萃取温度、CO2的流量、萃取时间、夹带剂的使用、分离温度和原料粒度等方面对萃取效果的影响,并对其中影响较为显著的因素进行了正交试验,通过极差和方差分析确定了萃取体系适宜的工艺条件。萃取压力为20 MPa,萃取温度为45℃,CO2的流量为15 L/h,萃取时间为2 h,夹带剂为95%的乙醇,分离温度为40℃,原料粒度为40~60目。     

分散液相微萃取-分光光度法测定水样中痕量肼

建立了分散液相微萃取-分光光度法测定痕量肼的新方法.在0.2 mol/L HCl介质中,以对二甲氨基苯甲醛(PDAB)为显色剂,三氯甲烷为萃取剂,乙醇为分散剂分离富集溶液中痕量肼.优化了反应酸度、萃取剂与分散剂的选择和用量、显色剂用量、显色时间和萃取时间等影响因素.最佳实验条件下,方法的线性范围0.80~120μg/L(r=0.999 5),检出限0.26μg/L.应用于实际水样测定,回收率在98.0%~103.4%之间,RSD在2.7%~3.2%之间.     

银离子配位萃取银杏叶中多萜长链化合物的研究

本文建立了银杏叶中多萜长链化合物Ag⁺配位萃取方法，构筑了含Ag⁺配位萃取体系。研究了萃取剂极性、萃取温度、Ag⁺浓度等因素对分配比D的影响，分析测定了银杏叶聚戊烯醇(PPs)与Ag⁺的配位萃取比m，确定了配位萃取条件及解离条件。试验结果表明，所建立的含Ag+配位萃取剂用于分离浓缩聚戊烯类化合物选择性好、效率高，萃取剂再生方法简便。     

醌类化合物的超临界流体萃取研究进展

综述了国内近20年来超临界流体萃取技术应用于醌类化合物分离的研究进展,重点介绍了超临界流体萃取技术在中草药中醌类化合物的分析测定方面的应用,分析了影响醌类成分提取效果的主要因素,优化萃取温度和萃取压力能够改善琨类化合物的分离效果,夹带剂的使用则有效地提高了超临界流体的萃取能力。     

稀土萃取分离技术方法研究

稀土在工业诸多领域中发挥着关键作用,在增材制造材料和介电材料等高新技术领域均显示出可期的应用前景。稀土元素的分离是衔接稀土资源与高性能稀土功能材料的关键过程,所以高效提纯稀土元素变得尤为重要。本文梳理了化学沉淀法、离子交换与吸附法、萃取色层法、溶剂萃取法、液膜分离法这些经典方法和化学气相传输法、氧化还原法、萃取沉淀法、微生物法、非平衡溶剂萃取法这些新技术方法的优缺点和适用性,侧重分析了这些技术方法在节能减排方面的最新研究情况,并展望了稀土分离提纯领域的重点发展方向,以期为稀土资源的绿色高效开发利用提供依据和借鉴。     

蓝靛果的化学成分及其提取分离研究进展

蓝靛果（Lonicera cearulea L.）是一种天然野生的可食用浆果,具有清除自由基、抑制炎症通路相关蛋白的磷酸化、抑制癌细胞增殖等生理活性,其抗氧化、调节血脂、抗肿瘤和防辐射等保健功效可应用于调节肠道菌群结构、抗癌、抗肥胖和保护视力等多个功能食品领域,且蓝靛果抗寒能力强,易于种植,具有极高的市场开发价值。研究总结整理了蓝靛果中活性化学成分（原花青素类、花青素类、花色苷类、黄酮类、有机酸类、多糖类及其它类化合物）的化学信息,归纳整理了不同类型化学成分的提取分离技术（溶剂提取法、酶解法、微波辅助提取法等）,以期为蓝靛果深入研发及深加工产品的开发提供依据。     

Purification of Astaxanthin from Laminaria japonica by Ionic Liquid-based Monolithic Cartridge

An effective and accurate method was developed for the extraction of astaxanthin from Laminaria japonica with subsequent separation by ionic liquid-based monolithic cartridge. The optimized extraction conditions including extraction solvent(ethanol), extraction time(90 min) and ultrasonic power(75 W) were obtained by systematical investigation. Chromatographic analysis was performed on a C₁₈ column with ultraviolet(UV) detection at 476 nm, and a solution consisting of methanol/acetonitrile/H₂O/dichloromethane(83:6:6:5, volume ratio) was used as the mobile phase at a flow rate of 0.7 mL/min. After ionic liquid-based monolithic solid phase extraction, 17.82 μg/g astaxanthin was obtained from Laminaria japonica. This ionic liquid-based monolithic cartridge exhibits high affinity and selectivity for astaxanthin, and it can be potentially used as the stationary phase of high performance liquid chromatography(HPLC).     

同时蒸馏萃取GC-MS分析刺异叶花椒叶挥发油化学成分

研究黔产刺异叶花椒叶挥发油的化学成分，采用同时蒸馏萃取提取并用气相色谱-质谱进行分离测定，共分离出67种成分，鉴定出37个化合物，主要成分为萜烯化合物及其衍生物，柠檬烯为19．31％，里哪醇为15．26％，桧烯为13．60％。     

Optimization of a liquid-liquid extraction method for HPLC-DAD determination of penicillin-V in human plasma

Optimization of a liquid-liquid extraction procedure used for isolation of penicillin-V in human plasma samples and the subsequent HPLC-DAD analysis are reported. Some aspects related to the stability of penicillin-V in plasma and according to pH are also given. From seven tested solvents, the highest extraction yield was obtained with methyl-t-buthyl ether. Influence of the extraction parameters, such as pH of aqueous phase, sample/solvent volumetric ratio, and extraction duration, is discussed. HPLC separation was achieved on an Eclipse XDB-C8 column, using a mobile phase composed by aqueous phosphate buffer (pH=7.3), methanol and acetonitrile in the ratio 8:1:1. Quantitation limits of 50 ng/ml were obtained. The optimal sample preparation method and HPLC-DAD separations were used for a bioequivalence study, made on 36 volunteers.     

Subcritical water extraction of organic matter from sedimentary rocks

Subcritical water extraction of organic matter containing sedimentary rocks at 300 °C and 1500 psi produces extracts comparable to conventional solvent extraction. Subcritical water extraction of previously solvent extracted samples confirms that high molecular weight organic matter (kerogen) degradation is not occurring and that only low molecular weight organic matter (free compounds) are being accessed in analogy to solvent extraction procedures. The sedimentary rocks chosen for extraction span the classic geochemical organic matter types. A type I organic matter-containing sedimentary rock produces n-alkanes and isoprenoidal hydrocarbons at 300 °C and 1500 psi that indicate an algal source for the organic matter. Extraction of a rock containing type II organic matter at the same temperature and pressure produces aliphatic hydrocarbons but also aromatic compounds reflecting the increased contributions from terrestrial organic matter in this sample. A type III organic matter-containing sample produces a range of non-polar and polar compounds including polycyclic aromatic hydrocarbons and oxygenated aromatic compounds at 300 °C and 1500 psi reflecting a dominantly terrestrial origin for the organic materials. Although extraction at 300 °C and 1500 psi produces extracts that are comparable to solvent extraction, lower temperature steps display differences related to organic solubility. The type I organic matter produces no products below 300 °C and 1500 psi, reflecting its dominantly aliphatic character, while type II and type III organic matter contribute some polar components to the lower temperature steps, reflecting the chemical heterogeneity of their organic inventory. The separation of polar and non-polar organic compounds by using different temperatures provides the potential for selective extraction that may obviate the need for subsequent preparative chromatography steps. Our results indicate that subcritical water extraction can act as a suitable replacement for conventional solvent extraction of sedimentary rocks, but can also be used for any organic matter containing mineral matrix, including soils and recent sediments, and has the added benefit of tailored extraction for analytes of specific polarities.     

Multiscale modeling of solvent extraction and the choice of reference state: Mesoscopic modeling as a bridge between nanoscale and chemical engineering

This article highlights current paradigms and challenges in modeling of lanthanides and actinides solvent extraction by lipophilic extractants. Within the multiscale approach, complex phenomena that occur in solvent systems can be rationalized at different length scales. Strengths and drawbacks of quantum and classical simulations, as well as mesoscopic modeling, are presented. In the multiscale modeling, the definition of standard states is of paramount importance because it dictates the amount of collective effects included within calculations. Mesoscopic modeling of the transfer and the aggregation free energies can be used to successfully predict properties of extraction systems at phenomenological scale and to assist chemical engineering of separation industry.     

Sampling of organic volatiles in the atmosphere at moderate and low pollution levels

Several techniques are available for measuring organic volatiles in the atmosphere. For measurements at low and moderate pollution levels (between several μg m^?3 and a fraction of a μg m^?3), the existing methods can be adopted to a broad range of different compounds. Whole-air sampling in stainless-steel containers with metal bellows valves combined with subsequent gas chromatographic separation after preconcentration in the laboratory is probably the best procedure for low and medium molecular weight trace gases of moderate or low polarity and reasonable chemical stability (e.g., hydrocarbons and halocarbons). For organic compounds of lower volatility, adsorptive sampling on non-polar porous organic polymers (e.g., Tenax) and thermal desorption combined with cryotrapping and gas chromatographic separation of the sampled compounds is widely used. However, there are often substantial problems due to artefact formation or loss reactions. Owing to the generally larger sample volumes, these problems are even more pronounced for sorptive sampling techniques combined with sample recovery by solvent extraction. Unfortunately, the general understanding of the various processes of sample degradation due to chemical reactions of reactive components of the atmosphere with each other or with the sorbent is not yet sufficient to allow reasonable estimates of the extent of such interferences without elaborate test procedures.     

Water as a green solvent combined with different techniques for extraction of essential oil from lavender flowers

Using water as a green solvent with a variable geometry makes use of physical and chemical phenomena that are fundamentally different from those applied in conventional extraction techniques such as hydro-distillation, steam distillation or solvent extraction. Advantages and drawbacks of using water as a solvent with different physical and chemical states have been compared. A total of ten extraction techniques: hydro-distillation (HD), steam distillation (SD), turbo-hydro-distillation (THD), salt-hydro-distillation (NaCL-HD), enzyme-hydro-distillation (Enzyme-HD), micelle-hydro-distillation (Micelle-HD), ultrasound-hydro-distillation (US-HD) or subcritical water-hydro-distillation (SW-HD), solvent-free microwave extraction (SFME) and microwave steam distillation (MSD) were used to extract the essential oil from lavender (Lavandula L.) and their results were compared. The quantity was measured by the yield of essential oil and the quality was evaluated using the oil composition especially the content of linalyl acetate, linalool and terpin-4-ol compared with the corresponding control sample: Hydro-distillation. For environmentally friendly of the process: extraction time, total energy consumption and CO₂ emission were considered and compared with conventional hydro-distillation. The mechanism explaining the linalyl acetate degradation has been resolved by using COSMO-RS software. Based on the present experimental conditions, it is recommended that lavender oil may be produced preferably by steam distillation assisted by microwave extraction to reduce the by-product formation by various chemical reactions and to get better oil recoveries.     

Anion-exchange and solvent extraction studies on the separation of radioiodine with particular reference to the production of 123I via proton irradiation of 123Te metal target

The separation of radioiodine was investigated using two wet chemical procedures, namely anion-exchange and solvent extraction. Some factors affecting the separation, such as HCl, NaOH and tetrabutyl ammonium bromide (TBAB) concentrations, used solvents ethyl acetate, benzene and carbon tetrachloride and different quaternary ammonium salts were studied. For each procedure the optimum conditions were deduced. The separation of ¹²³I was effected from proton-irradiated ¹²³Te target under the optimized conditions of the two procedures. The yield of ¹²³I obtained using the Dowex 21k anion-exchanger and tetrabutyl ammonium bromide solution as eluting agent was 88±3%; the radionuclidic purity was high and the time needed was 60 minutes. In solvent extraction process using TBAB in ethyl acetate as the extracting agent, the yield of ¹²³I was low (47±3%), the radionuclidic purity was not as good as in the anion-exchange method, and the time needed was 150 minutes. Therefore, the anionexchange method is preferable. A comparison of this wet chemical method of separation of ¹²³I with the commonly used dry distillation method is given. The wet method appears to be more suitable when a ¹²³Te metal target is used.