电动流动分析的色谱分离研究

建立了一种基于增压电渗泵驱动、整体柱分离和紫外检测相结合的电动流动分析系统。研究了载流溶液中甲醇的体积分数对电渗泵空载流量、输出压强、移动相流量和分离度的影响。在4950V的外加电压下,以含0.5mmol/L六亚甲基四胺的45%甲醇溶液为泵载流,电渗泵的流量和输出压强分别为0.58mL/min和0.79MPa,以泵载流为流动相,该系统对苯和萘进行了反相色谱分离。电动流动分析系统设备简单、操作方便、功能多样。对苯和萘的分离结果表明,电动流动分析系统可用于样品的色谱分离。     

新型毛细管等电聚焦驱动方法的建立及其应用

毛细管等电聚焦(CIEF)在生物分离分析领域中的发展迅速．CIEF可分为两步法聚焦和一步法聚焦．电渗流(EOF)可作为一种新的驱动力．Rassi等根据串连体系中电渗流速率将被平均化的原理,将未涂层毛细管与聚乙二醇涂层的毛细管通过聚四氟乙烯管耦合起来,成功地利用毛细管区带电泳快速分离蛋白．此外,利用电渗流输液原理设计的电渗泵还可用作流动注射和微柱液相色谱的驱动系统。     

聚丙烯酸酯类毛细管整体柱的制备及其在加压毛细管电色谱中的应用

毛细管电色谱(CEC)是毛细管电泳(CE)和微径液相色谱(micro—HPLC)技术的结合,是集CE的电子迁移机制和micro-HPLC的分配分离机理发展起来的一种高效微分离技术．CEC以塞子流型的电渗流代替抛物线流型的压力流,具有CE的高效性,能够分离电中性化合物而具有HPLC的高选择性．     

芯片电色谱的最新研究进展及应用

本文主要综述了近5年(2005－2009年)来芯片电色谱(μCEC)的新发展。详细描述了芯片设计制作、进样富集,色谱柱填充技术,电渗流(EOF)操控与电色谱分离机制等最新研究进展,也包含μCEC的一些新应用;此外,对μCEC技术的发展趋势和前景进行了展望。     

电动泵技术研究进展

电液动力学（EHD）研究的是在流体上施加电场后流体的流动。在微分析系统中,EHD的主要应用是电动泵（EKP）技术即电泳泵和电渗泵两个主要泵技术。这些独特的泵技术被广泛应用在推动极小截面的管道中化学和生物流体流动,管道尺寸从平方毫米到平方微米量级,甚至纳米通道量级。近年来,电渗泵出现了填充床、整体柱、平行多通道、纳米通道和微孔膜等各种新的形式,显示了其在微分析系统中的集成化和在毛细管液相色谱、流动注射分析和药物输送等应用研究中的潜力。本文对电动泵技术进行评述。     

毛细管电泳法在手性分离中的应用及进展

近年来,毛细管电泳(CE) 手性分离方法的研究主要集中在各种手性添加剂与对映体药物的匹配及实验条件的最优化选择上.目前,较为成熟的CE分离模式有:区带电泳(CZE)、凝胶电泳(CGE)、等速电泳(CITP)、胶束电动色谱(MEKC)和非水电泳(NACE)等,并已成功地用于手性化合物对映体的分离.CE手性分离研究正朝着新型手性选择剂的研制和实现与其他各种定性分析仪器及其他色谱分离模式的联用方向发展.     

对-叔丁基杯[8]芳烃键合硅胶制备及其毛细管电色谱性能研究

以γ-(环氧丙氧)丙基键合硅胶为前体,于硅胶表面键合环氧基,在催化剂存在下以杯芳烃钠盐开环制备杯芳烃键合硅胶固定相.该方法反应条件温和,适用性强.将这个新方法首次用于制备对-叔丁基杯[8]芳烃电色谱键合固定相(C8BS),采用加压电色谱初步评价其电色谱性能.研究结果表明,C8BS电渗流(Electrosmoticflow,EOF)较小,但通过控制键合反应及使用压力辅助电色谱可部分弥补上述不足.该固定相的EOF受流动相pH影响小(pH=3-8),同时大环配体屏蔽效应能有效地克服硅羟基引起的碱性化合物拖尾现象,这对电色谱分离具有重要意义.通过分步封尾研究EOF的来源发现,杯芳烃酚羟基对EOF有弱的贡献,这与报道的杯芳烃涂层具有径向电渗流调控能力相一致.     

色谱技术在药物-血浆蛋白相互作用研究中的应用进展

小分子药物进入人体血液循环系统后与人血清白蛋白(HSA)、α₁ -酸性糖蛋白(AGP)等血浆蛋白存在广泛的相互作用,这些相互作用深刻影响药物在体内的分布及其与靶标蛋白的结合,进而影响药物效应的发挥。深入探究药物与血浆蛋白间的相互作用对于候选药物的成药性优化、新药研发、联合用药的风险评控等意义重大。而发展高效、灵敏、准确的分析检测方法是开展药物-血浆蛋白相互作用研究的关键。近年来,色谱技术由于其高通量、高分离性能、高灵敏度等特点在该领域得到了广泛的应用,包括测定血浆蛋白翻译后修饰对药物结合的影响,多种药物的竞争性结合等。其中,高效亲和色谱(HPAC)和毛细管电泳(CE)应用最为广泛,能够通过多种分析方法获取结合常数、结合位点数、解离速率常数等相互作用信息。该文着重综述了HPAC和CE在药物-血浆蛋白相互作用研究中的常用策略及最新研究进展,包括HPAC中常用的前沿色谱法、竞争洗脱法、超快亲和提取法、峰值分析法和峰衰减分析法,以及CE中常用的亲和毛细管电泳法(ACE)和毛细管电泳前沿分析法(CE-FA)等。最后,该文还对当前色谱方法存在的不足进行了总结,并对色谱技术在药物-血浆蛋白相互作用研究领域的应用前景和发展方向进行了展望。     

基于微流控芯片的色谱系统的研究进展及其应用

近年来,基于微流控芯片的色谱技术研究取得了快速发展。本文对微流控芯片上色谱柱的加工方法、泵阀驱动控制装置的设计、集成及联用色谱系统的研制及其应用等方面予以综述,涉及文献66篇。     

单级高压微流量电渗泵的研究

设计了一种高压微流量电渗泵。泵体主要由高压电源、电渗柱、毛细通道、导电空心电极以及气泡去除器、压力传感器等构成。单级电渗泵可以给出0～20MPa范围的输出压力和nL～μL级输出流量。输出压强和输出流量取决于电压、填充柱阻力和流体性质。     

复杂电渗泵系统的输液特征

基于对电渗泵中压强产生原理的讨论, 对新兴的复杂串、并联电渗泵系统的流体输液特征加以研究. 在多级串联电渗泵系统中, 可以通过增加电渗泵的级数或操作电压来提高泵系统产生的压强, 但是单一流路的输液能力有限. 而在多级并联电渗泵系统中, 输液量也可以通过增加电渗泵的级数或操作电压得到提高. 在这一体系中, 尽管输液量的叠加有利于其在更为广泛的领域中应用, 但是因Joule热产生的电场强度与电渗流速度线性关系的偏离也使得其线性范围变小, 不利于操作条件的控制.     

Electroosmotic pump-assisted capillary electrophoresis of proteins

A new method for protein analysis, that is, electroosmotic pump-assisted capillary electrophoresis (EOPACE), is developed and demonstrated to possess several advantages over other CE-based techniques. The column employed in EOPACE consists of two linked sections, poly(vinyl alcohol) (PVA)-coated and uncoated capillaries. The PVA-coated capillary column is the section for protein electrophoresis in EOPACE. Electroosmotic flow (EOF) is almost completely suppressed in this hydrophilic polymer coated section, so protein electrophoresis in the PVA-modified capillary is free of irreversible protein adsorption to the capillary inner wall. The uncoated capillary section serves as an electroosmotic pump, since EOF towards cathode occurs at neutral pH in the naked silica capillary. By the separation of a protein mixture containing cytochrome c (Cyt-c), myoglobin and trypsin inhibitor, we have demonstrated the advantages of EOPACE method over other relevant ones such as pressure assisted CE, capillary zone electrophoresis (CZE) with naked capillary and CZE with PVA-coated capillary. A significant feature of EOPACE is that simultaneous separation of cationic, anionic and uncharged proteins at neutral pH can be readily accomplished by a single run, which is impossible or difficult to realize by the other CE-based methods. The high column efficiency and good reproducibility in protein analysis by EOPACE are verified and discussed. In addition, separation of tryptic digests of Cyt-c with the EOPACE system is demonstrated.     

Electroosmotic Driving Liquid Using Nanosilica Packed Column

The packed-bed electroosmotic pump (p-EOP) can manipulate liquid with pressure as high as 50 MPa and micro flowrate ranging from several nL/ min to several μL/min1-3. The p-EOP is matching to micro systems and suitable for developing chip liquid chromatography/electrochromatography for proteomics and high throughput HPLC for drug discovery4-6. There are some efforts to improve the performance p-EOP7-8 recently. In this paper, the nanosilica was chosen as the electroosmotic carrier to i…     

Headspace‐single drop microextraction with a commercial capillary electrophoresis instrument

Automated coupling of headspace‐single drop microextraction (HS‐SDME) and CE has been demonstrated using a commercial CE instrument. When a drop hanging at the inlet tip of a capillary for CE is used as the acceptor phase, HS‐SDME becomes a simple but powerful sample pretreatment technique for CE before injection to facilitate sample cleanup and enrichment. By combining HS‐SDME with an on‐line sample preconcentration technique, large volume sample stacking using an electroosmotic flow pump, the sensitivity can be improved further. The overall enrichment factors for phenolic compounds were from 1900 to 3400. HS‐SDME large volume sample stacking using an electroosmotic flow pump was successfully applied to a red wine sample to obtain an LOD of 4 nM (0.8 ppb) for 2,4,6‐trichlorophenol which is a precursor for 2,4,6‐trichloroanisole causing the foul odor in wine called cork taint.     

Electroosmotic mixing in microchannels

Mixing is an essential, yet challenging, process step for many Lab on a Chip (LOC) applications. This paper presents a method of mixing for microfluidic devices that relies upon electroosmotic flow. In physical tests and in computer simulations, we periodically vary the electric field with time to mix two aqueous solutions. Good mixing is shown to occur when the electroosmotic flow at the two inlets pulse out of phase, the Strouhal number is on the order of 1, and the pulse volumes are on the order of the intersection volume.     

电渗泵在微柱液相上的应用

 设计评价了一种能够取代机械泵的电渗泵 (EOP) ,该泵可以产生 2 0MPa～ 6 0MPa的输出压力和几十nL/min～ 3μL/min的输出流量 ;用乙腈 水作为流动相 ,在 14cm× 32 0 μmi d (C18,5 μm )微柱上分离了萘、蒽、菲3种物质的混合试样 ,证明EOP在微柱液相领域有广阔的应用前景。     

电渗泵—流动注射在线稀释法在火焰原子吸收光谱分析高浓度样品中？…

采用电渗泵流动注射－火焰原子吸收法（ＦＩ－ＦＡＡＳ）,研究了高浓度镁样品的在线稀释和分析。电渗泵在低流量时有很好的稳定性。利用控制采样时间的办法,可以准确采集微量样品,在线稀释。同时使用Ｔ型客对雾化量进行补偿,在线稀释倍数可达１０００以上,相对标准偏差〈１．５％（ｎ＝６）。通过改变采样电压（速度）,载流速度和采样时间可以方便地得到不同的稀释倍数,测定速度可达１００个／ｈ样品以上。     

双模高压电源在填充型电渗泵流量控制中的应用

研制了两台填充型电渗泵,利用双模对接高压电源可以产生0～60kV超高压,通过提高操作电压,增加了泵系统产生的流量,给出了电渗泵在高电压范围内电压与流量的关系曲线。实验结果表明,电压与流量在高压范围内仍呈线性关系,线性相关系数达到0.9996。同时,通过条件优化,克服了焦耳热,使电渗泵在高电压范围内稳定运行。     

Electroosmotic pumping in microchips with nonhomogeneous distribution of electrolytes

A general equation to calculate the node pressure at a junction in a microfluidic network is presented. The node pressure is generated from both the hydrodynamic flow due to the external applied hydraulic pressures and the electrokinetic flow resulted from the applied electric field. Pure electroosmotic flow has a plug-flow profile and pressure flow has a parabolic flow profile. In a first order approximation, these two flows can be treated separately, and the total flow is the sum of the two. An externally applied pressure simply creates a constant offset in the node pressure as long as the flow resistances remain the same. In a nonhomogeneous microfluidic network, where the electrical resistivity or the electroosmotic mobility is not constant everywhere, the differences in electroosmotic flow in various sections of the network will create an electroosmotically induced pressure at the internal nodes. Our theoretical approach can easily be extended to networks with more than one internal node. One prediction of this theory is that any variation in electroosmotic mobility or solution resistivity in different network branches will generate a pressure, and can thus be used as a pump. As an example, we demonstrate electroosmotic pumping in a high-low buffer system.