首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
液/液界面电化学分析在双水相萃取中的应用   总被引:3,自引:1,他引:2  
阎恭喜  俞泽穆 《分析化学》1995,23(5):517-521
用循环伏安法(CV)研究了聚乙二醇(PEG)-6000/磷酸钾(K2PO4)双水相体系中各种组分对麦迪霉素推动质子在水/硝基苯(W/NB)界面上转移行为的影响,用液/液界面电化学分析技术检测了麦迪霉素在双水相体系中的分配情况,发现了麦迪霉在双水相体系中的选择性分配,其分配系数大于44,测定的线性范围为50~800μg/mL,回收率大于93%,  相似文献   

2.
报道了由正负离子表面活性剂与高聚物混合溶液形成的一种可用于蛋白南的分离及分析的新型双水相萃取体系,研究了正负离子表面活性剂(溴十二烷基三乙铵/十二烷基硫酸钠)分别与葡萄糖和聚乙二醇混合双水相体系的形成规律,相行为及牛血清蛋白和溶菌酶在双水相体系中的分配,通过在高聚物分子中接上亲和配基,研究蛋白质在双水相体系中的亲和分配,结果表明,在该体系中,表面活性剂与高聚物分别富集于不同相中,升高温度及加入无机盐均可促进双水相体系的形成,不同蛋白质的可分配于不同的相中,亲和配基的引入极大地增强了蛋白质分配的选择性。  相似文献   

3.
外加盐作用形成的正负离子表面活性剂双水相   总被引:1,自引:0,他引:1  
癸基三乙基溴化铵-癸基磺酸钠(C10NE-C10SO3)等摩尔混合均相体系(即使在表面活性剂总浓度高达0.2 mol•L-1时仍然可形成稳定的均相溶液)在外加盐NaF、Na2SO4和Na3PO4的作用下可自发分离成两个水相(双水相).研究了该类双水相体系的形成、相行为及其对牛血清蛋白(BSA)的分配,并与普通的正负离子表面活性剂混合双水相体系进行了比较.结果表明,该类双水相体系克服了普通的正负离子表面活性剂混合双水相体系的一些不足,具有一些独特的优点.该类双水相体系的相行为可以通过外加盐进行调控,通过外加盐的种类来调控和优化BSA的分配行为.图1表2参8  相似文献   

4.
铟在聚乙二醇-硫酸铵双水相体系中的分配   总被引:2,自引:0,他引:2  
研究了稀散元素铟在有配合剂PAR(4-(2-吡啶偶氮)-间苯二酚)存在和无PAR存在的聚乙二醇PEG-(NH4)2SO4双水相体系中的分配行为。讨论了酸度、PEG分子量、PEG浓度及温度等因素对铟分配比的影响,发现酸度对分配比的影响最大,随着PEG分子量的增加及温度的上升分配比逐渐增大;随着PEG浓度的增加分配比逐渐减小。  相似文献   

5.
用分光度法研究了[Bmim]BF4/(NH4)2SO4双水相体系萃取山楂黄酮和多糖的相行为,考察了同时提取这两种组分时[Bmim]BF4的浓度、(NH4)2SO4的浓度、山楂的用量、超声萃取时间等因素对双水相的上下相体积以及分配系数的影响。结果表明:(1)离子液体浓度的增加,双水相的上、下相体积分别明显增大和减小。但黄酮和多糖在双水相中的分配系数仅有波动,均小于5%;(2)硫酸铵浓度的增加,双水相的上下相体积分别明显减小和增大。同时黄酮和多糖的分配系数均有较明显先降低后升高的趋势;(3)山楂质量的增减,不影响双水相的形成,但存在一个实验条件下的溶出饱和值,该值为0.15g,此时黄酮和多糖的分配系数最大;(4)超声萃取时间的延长或缩短,同样不影响双水相的形成,但存在对山楂有效成分达到饱和溶出的阈值,对于黄酮为25min,多糖为20min。  相似文献   

6.
双水相萃取法从风干香肠中分离提取蛋白酶   总被引:9,自引:0,他引:9  
双水相萃取(ATPS)是近年来发展起来的蛋白纯化方法。为了扩展该方法适应领域,同时为风干香肠形成过程酶系的研究提供具体方法。本实验研究了运用双水相技术分离提取风干香肠中蛋白酶,对构成双水相体系中的PEG分子量、浓度和类型以及盐浓度的影响进行了分析。确定了双水相组成体系为20%PEG1000(m/m)和25%MgSO4(m/m),在此体系中风干香肠的蛋白酶主要分布在上相,最高酶活12.37U/μg;纯化倍数为4.61;回收率为85%。通过分子筛层析对比,表明风干香肠经过双水相分离提取杂蛋白峰被除去,而蛋白酶峰几乎未受到影响,说明该双水相体系萃取香肠中蛋白酶具有良好的专一性。调解双水相pH值对蛋白酶的萃取没有影响,而添加电解质NaCl反而产生不利影响。  相似文献   

7.
本文对氨基酰化酶在由聚乙二醇/盐组成的双水相系统中的分配进行了研究。氨基酰化酶在双水相系统中的分配系数受系统中聚乙二醇平均分子量及浓度、盐的种类及浓度、pH值、外加盐及带电聚乙二醇等因素的影响。它为大规模提取纯化氨基酰化酶提供了一种有希望的方法。  相似文献   

8.
以含羟丙基-β-环糊精(HP-β-CD)手性识别剂的醇/盐双水相体系作为一种新型的手性识别萃取体系,研究了α-环己基扁桃酸(CHMA)对映体在其中的手性识别行为.详细考察了HP-β-CD浓度、CHMA浓度、乙醇和硫酸铵质量分数、体系温度和pH值等因素对CHMA对映体分配比(D)和分离因子(α)的影响.结果显示,含有手性识别剂HP-β-CD的乙醇∕硫酸铵双水相体系对CHMA对映体具有很强的手性识别能力;体系中HP-β-CD浓度、乙醇质量分数、温度和pH值等因素对对映体的分离度影响较大;在体系温度为40 ℃,pH值为2,乙醇质量分数为30%,硫酸铵质量分数为15%,HP-β-CD的浓度为50 g.L-1,CHMA浓度为0.5 mmol.L-1时,手性识别分离效果最佳,分离因子(α)达到了1.86.  相似文献   

9.
水榆花楸叶中所含的黄酮类化合物具有一定的药用价值,利用双水相技术萃取水榆花楸叶中的黄酮是一种有效的分离纯化方法。本文考察了不同种类的无机盐与不同相对分子量的PEG组成的双水相体系的两相性质,研究了PEG1000-Na_2SO_4双水相体系中分离纯化水榆花楸黄酮时PEG的质量分数、Na_2SO_4的质量分数、温度、p H、KCl添加量这5个因素对分配行为的影响,并通过正交实验优化了试验条件。结果表明最佳双水相萃取条件为:Na_2SO_4的质量分数为15%,PEG1000质量分数为30%,p H为9,提取温度为25℃,KCl的添加量为3%,此时原料中黄酮的萃取率可高达97.01%。因此,该体系是一种高效分离纯化水榆花楸叶中黄酮的方法。  相似文献   

10.
建立了温敏性聚合物EOPO-K2HPO4双水相浮选技术,并结合HPLC-UV,分离检测了日常食物中的痕量环丙沙星(CIP).讨论了盐浓度、EOPO浓度、pH值、浮选时间、浮选速率对浮选率的影响,并采用响应曲面法(RSM)对实验条件进行了优化.在最优条件(K2HPO4浓度为55%(w/w)、浮选时间为50 min、浮选流速为28 mL/min)下,CIP的萃取率达到了98.9%.在二次萃取中,随着温度的诱导,CIP的萃取率高达87.6%,且相对标准偏差(RSD)在0.3% ~0.7%.双水相组分被成功回收利用达到两次以上.  相似文献   

11.
In‐situ extraction and condensation of various dyes were carried out in a phase‐separation region of a thermoresponsive polymer aqueous solution generated by near infrared (NIR) laser heating under a microscope. The NIR laser irradiation was directed at a chromium line deposited on a glass substrate, thereby causing local heating of the solution due to the photothermal effect. A phase‐separation region was formed by dehydration of the thermoresponsive polymer followed by ejection of water outside of the phase‐separation region. When various dyes were included in the solution, some dye molecules were extracted into the phase‐separation region, where they condensed. In the case of poly(N‐isopropylacrylamide) (PNIPAM, 10 wt % in an aqueous solution) as the thermoresponsive polymer and crystal violet (CV) as the dye (0.1 mM ), CV condensed by about 25 times. It was found that one of the necessary conditions for the extraction/condensation is the hydrophobicity of the dye molecule; however, the dominant cause for accumulating inside the PNIPAM chain is the molecular interaction between the amide group in the side chain of PNIPAM and the functional groups such as carbonyl or amino groups in the dye molecules.  相似文献   

12.
Graphene oxide(GO) has attracted extensive attention due to its unique properties and potential applications.Here,we report the investigation of GO nanosheets as a stationary phase for capillary gas chromatographic(GC) separations.The GO column,fabricated by a new one-step coating approach,showed average McReynolds constants of 308,suggesting the medium polar nature of the GC stationary phase.The GO stationary phase achieves good separation for analytes of different types with good peak shapes,especially for H-bonding analytes,such as alcohols and amines.The different retention behaviors of GO stationary phase from the conventional stationary phase may originate from its multiple interactions with analytes,involving H-bonding,dipole-dipole,π-π stacking and dispersive interactions.Moreover,GO column showed good separation reproducibility with relative standard deviation(RSD%) less than 0.24%(n = 5) on retention times of analytes.  相似文献   

13.
采用扫描电镜、光学显微镜和光散射仪研究了环氧化聚丁二烯-聚苯乙烯嵌段共聚物(EBS)对聚苯醚(PPO)/双酚A型环氧树脂(DGEBA)/4,4’-二(2,6-二甲基苯胺基)甲烷(DIM-DDM)体系反应诱导相分离行为的影响. 实验结果表明, EBS的加入对PPO/DGEBA/DIM-DDM体系反应诱导相分离的演化过程有阻滞作用. 随着EBS加入量的增加, 体系形成双连续相结构所需的PPO含量范围变宽, 而对于相同PPO含量、形成双连续相的体系则相结构尺寸减小.  相似文献   

14.
Three-liquid-phase partitioning of Pd(II), Pt(IV) and Rh(III) in systems of S201(diisoamyl sulfide)/nonane-EOPO(polyethylene oxide-polypropylene oxide random block copolymer)-Na(2)SO(4)-H(2)O was investigated. Experimental results indicated that the selective enrichment of Pd(II), Pt(IV) and Rh(III) respectively into the S201 organic top phase, EOPO-based middle phase and Na(2)SO(4) bottom phase was achieved by control over the phase behavior of the three-liquid-phase systems (TLPS). The microphase mass transfer behavior of Pt(IV), Pd(II) and Rh(III) was closely related to the micellization of EOPO molecules. A suggested micro-mechanism model and a mass transfer model describe the micellization of EOPO molecules and the effect on mass transfer of platinum ions across the microphase interfaces. The salting-out induced continuous dehydration and ordered arrangement of the hydrophilic PEO segments in amphiphilic EOPO micelle, and these are the main driving forces for mass transfer of platinum metal ions onto the exposed activity sites of the dehydrated PEO segments. The differences in microphase interfacial structure of EOPO micelles are crucial for the efficient separation between Pt(IV), Pd(II) and Rh(III).  相似文献   

15.
An amphiphilic poly(ethylene oxide)‐block‐poly(dimethylsiloxane) (PEO–PDMS) diblock copolymer was used to template a bisphenol A type epoxy resin (ER); nanostructured thermoset blends of ER and PEO–PDMS were prepared with 4,4′‐methylenedianiline (MDA) as the curing agent. The phase behavior, crystallization, hydrogen‐bonding interactions, and nanoscale structures were investigated with differential scanning calorimetry, Fourier transform infrared spectroscopy, transmission electron microscopy, and small‐angle X‐ray scattering. The uncured ER was miscible with the poly(ethylene oxide) block of PEO–PDMS, and the uncured blends were not macroscopically phase‐separated. Macroscopic phase separation took place in the MDA‐cured ER/PEO–PDMS blends containing 60–80 wt % PEO–PDMS diblock copolymer. However, the composition‐dependent nanostructures were formed in the cured blends with 10–50 wt % PEO–PDMS, which did not show macroscopic phase separation. The poly(dimethylsiloxane) microdomains with sizes of 10–20 nm were dispersed in a continuous ER‐rich phase; the average distance between the neighboring microdomains was in the range of 20–50 nm. The miscibility between the cured ER and the poly(ethylene oxide) block of PEO–PDMS was ascribed to the favorable hydrogen‐bonding interaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 3042–3052, 2006  相似文献   

16.
《Analytical letters》2012,45(14):2223-2234
This study reports the application of a dispersive extraction method for the extraction and separation of phenolic acids from Salicornia Herbacea L. using silica-confined ionic liquids as the sorbent. A suitable sorbent for phenolic acid extraction and separation was first identified based on the adsorption behavior of phenolic acids on different silica-confined ionic liquids. The sample was then mixed with the optimized sorbent and solvent to achieve dispersive extraction. After transferring the supernatant to an empty cartridge, a solid phase extraction process was used to separate the three organic acids from other interferences. Through systematical optimization, the optimal conditions were obtained with high recovery rates of protocatechuic acid (98.1%), caffeic acid (89.4%), and ferulic acid (92.2%). Overall, the proposed method expected to have wide applicability.  相似文献   

17.
以正硅酸甲酯(TMOS)为前驱体, 0.01 mol·L-1盐酸(HCl)为催化剂, 环氧丙烷(PO)为凝胶促进剂, 粘均分子量(Mv)为10000的聚氧化乙烯(PEO)为相分离诱导剂, 采用溶胶-凝胶伴随相分离制备SiO2多孔块体材料,利用差热分析(DTA)、傅里叶变换红外(FT-IR)光谱、扫描电镜(SEM)、X射线衍射(XRD)、汞压、N2吸附/脱附等测试技术对所制得的SiO2多孔块体进行了表征, 探讨了环氧化物调控溶胶-凝胶以及PEO诱导相分离机理. 结果表明, 加入PEO能诱导SiO2凝胶发生相分离, 当PEO/TMOS摩尔比为0.0018时, 可以获得共连续多孔结构的SiO2块体材料, 其大孔孔径分布在1-3 μm之间, 比表面积达719 m2·g-1, 孔体积为0.48 m3·g-1. 环氧丙烷因其环氧原子的强亲核性和不可逆的开环反应, 促进溶胶-凝胶转换, 同时借助吸附在SiO2低聚物上的PEO诱导SiO2凝胶相分离, 从而制备共连续大孔及骨架结构的多孔块体.  相似文献   

18.

A new hybrid gas separation membrane was prepared from poly(2,6-dimethyl-1,4-phenylene oxide) modified with graft copolyimide with side poly(methyl methacrylate) chains. The changes in the membrane structure on introducing up to 15 wt % modifier were evaluated by atomic force microscopy and density measurements. The microphase separation in modified polyphenylene oxide films was demonstrated. Introduction of graft copolyimide leads to an increase in the density of the hybrid films. The gas transport properties of the membranes were evaluated for H2, CO2, O2, O4, and N2. Introduction of up to 10 wt % modifier does not noticeably alter the permeability of the hybrid membranes to all the gases but increases the selectivity in gas separation.

  相似文献   

19.
A rapid and sensitive method has been developed for the determination of biphenyl and biphenyl oxide in water samples using dispersive liquid–liquid microextraction followed by gas chromatography. This method involves the use of an appropriate mixture of extraction solvent (8.0?µL tetrachloroethylene) and disperser solvent (1.0?mL acetonitrile) for the formation of cloudy solution in 5.0?mL aqueous sample containing biphenyl and biphenyl oxide. After extraction, phase separation was performed by centrifugation and biphenyl and biphenyl oxide in sedimented phase (5.0?±?0.3?µL) were determined by gas chromatography-flame ionisation (GC-FID) system. Type of extraction and disperser solvents and their volumes, salt effect on the extraction recovery of biphenyl and biphenyl oxide from aqueous solution have been investigated. Under the optimum conditions and without salt addition, the enrichment factors for biphenyl and biphenyl oxide were 819 and 785, while the extraction recovery were 81.9% and 78.5%, respectively. The linear range was (0.125–100?µg L?1) and limit of detection was (0.015?µg?L?1) for both analytes. The relative standard deviation (RSD, n?=?4) for 5.0?µg?L?1 of analytes were 8.4% and 6.7% for biphenyl and biphenyl oxide, respectively. The relative recoveries of biphenyl and biphenyl oxide from sea, river water and refined water (Paksan company) samples at spiking level of 5.0?µg?L?1 were between 85.0% and 100 %.  相似文献   

20.
反相高效液相色谱法制备松果菊苷标准品   总被引:12,自引:1,他引:11  
雷厉  宋志宏  屠鹏飞  吴立军  陈发奎 《色谱》2001,19(3):200-202
 利用反相制备高效液相色谱结合溶剂萃取、大孔吸附树脂柱色谱和葡聚糖凝胶LH 2 0柱色谱方法 ,从管花肉苁蓉的乙醇提取物中纯化制备了苯乙醇苷类化合物松果菊苷的标准品 ,纯度达到 98%以上。方法操作简便 ,重现性好 ,可用于松果菊苷及其他苯乙醇苷类化合物的大量制备。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号