高效毛细管区带电泳法分离人血清蛋白质的研究

 研究了高效毛细管区带电泳分离人血清蛋白质的电泳行为及实验条件 ,建立了分离血清蛋白质的高效毛细管区带电泳法。血清样品经硼酸缓冲液 (5 0 mmol/L,p H8.80 )稀释后 ,以 0 .1 mol/L硼酸缓冲液 (p H9.3 5 ,含4g/L PEG80 0 0 )为电泳介质 ,在 5 0 μm i.d.× 3 7cm弹性石英毛细管柱 (有效柱长为 3 2 cm)中进行电泳分离 ,以2 0 0 nm紫外波长检测。方法简便、快速、重复性好 ,1 2 min内便可完成对血清中蛋白质的电泳分离。     

毛细管区带电泳法测定板蓝根注射液中四种核苷的含量

采用毛细管区带电泳法测定了板蓝根注射液中胞苷、腺苷、鸟苷和尿苷的含量。电泳条件:采用未涂层石英毛细管(32.5 cm×50 μm i.d.,有效长度23.5 cm),以60 mmol/L硼砂溶液-10%(体积分数)异丙醇-20%（体积分数）乙腈为运行缓冲液,在25 ℃下以20 kV恒压电泳分离,压力进样 (1 kPa×10 s),检测波长254 nm。对电泳条件各因素进行了讨论,如缓冲液的种类、浓度和pH值,有机改性剂的种类和浓度,分离电压和毛细管温度等。样品经0.45 μm微孔滤膜过滤后直接进样;采用外     

胶束扫集毛细管电泳分离测定绿原酸和咖啡酸

采用胶束扫集毛细管电泳分离测定双黄连口服液中的绿原酸和咖啡酸.试验条件为:重力进样时间40 s;以20 mmol/L NaH_2PO_4,100 mmol/L 十二烷基磺酸钠(SDS)为电泳缓冲液(含体积分数15%甲醇,pH 2.20),分离电压-20 kV,检测波长214 nm,讨论了pH、SDS浓度、样品溶剂等对分离效果的影响.在优化条件下,绿原酸和咖啡酸的检出限分别达到1.02和0.168 μg/mL,线性范围分别为5.86～51.5 μg/mL和1.27～14.5 μg/mL.     

西他沙星差向异构体的毛细管电泳分离

以γ-环糊精和D-苯丙氨酸为手性选择剂,采用毛细管区带电泳成功地分离了新型抗菌素西他沙星差向异构体。考察了添加剂的种类、浓度和缓冲溶液的pH对毛细管电泳分离西他沙星的影响。分离电压为15 kV,选用60 cm(有效长度52.5 cm)×50 μm i.d.的石英毛细管,缓冲溶液组成为10 mmol/L KH2PO4-K2HPO4(pH 4.5),10 mmol/L CuSO4,20 mmol/L γ-环糊精和 10 mmol/L D-苯丙氨酸。实验结果表明,添加剂的种类和浓度是影响西他沙星手性分离的重要因素,只有当 D-苯丙氨酸、铜离子和γ-环糊精同时存在并达到一定浓度时,西他沙星差向异构体在毛细管电泳中才具有良好的分离效果。该方法可用于西他沙星差向异构体的定量分析。     

电场耦合法芯片电泳柱上电导检测特性研究

通过电场耦合作用对毛细管电泳柱上直流电导检测原理进行了分析, 利用带有双T结构检测池的玻璃和聚合物芯片对其特性进行了研究. 在电泳分离过程中, 电泳高电场通过检测通道耦合到出口的检测电极上并产生可被检测的电势差. 当导电性与支持电解质不同的组分谱带通过分离通道上的检测池时造成该电位差的变化, 该变化与溶液电导率、检测池长度和电场强度直接相关. 检测信号与基线相除得到的信号只和检测池中溶液的物理特征参数(电导率及电阻)有关. 用自制高阻抗信号转换系统可使芯片电泳电场强度提高到450 V/cm以上, 以1 mmol/L Tris-HCl为支持电解质, 在12 s内实现了K＋和Na＋的高重现性分离检测, 检出限达到5 μmol/L, 线性范围达两个数量级(10 μmol/L~2 mmol/L).     

MnCl_2改性γ-Al_2O_3毛细管填充柱气相色谱分析氢同位素

针对常规气相色谱填充柱分析稳定氢同位素的柱效低、峰宽大、保留时间长等问题,采用MnCl_2改性γ-Al_2O_3填充的石英毛细管柱开展了系统性柱效分析及氢同位素分析技术研究。研究结果表明,使用MnCl_2对γ-Al_2O_3进行改性后,可大大改善单纯的γ-Al_2O_3表面有序度、孔结构和吸附性质,并将正氢(o-H_2)和仲氢(p-H_2)峰洗脱在单一谱峰区域内。制备的长1.0 m、内径0.53 mm的石英毛细填充柱与热导检测器(TCD)级联测试,在体积浓度1至10 m L/L范围内有较好的线性关系,对于低浓度样品检测的相对误差不大于5%。H_2、HD和D_2的保留时间可分别缩短至39、46和60 s,检出限可分别降低至0.046、0.067和0.072 m L/L。毛细管填充柱较常规填充柱具有峰形尖锐、相邻组分分离度高、保留时间短、检出限低等优点,可用于低浓度氢同位素快速测量及氢同位素在线分析。     

毛细管电泳法快速检测消毒剂中的醋酸氯己定

建立了消毒剂中活性成分醋酸氯己定(又名:醋酸洗必泰)的毛细管电泳快速检测法。采用15 mmol/L磷酸盐-乙腈( 体积比为60∶40)缓冲体系,将醋酸氯己定在50 cm×75 μm i.d.的石英毛细管柱中进行电泳分离,电泳电压为15 kV,检 测波长为254 nm。同时,对毛细管电泳分析醋酸氯己定的条件(如缓冲液的种类、pH值、浓度及电泳电压等)进行了优化 。用该方法对消毒剂样品进行测定,在4 min内可完成分析。醋酸氯己定在质量浓度为0.01～0.10 g/L时线性良好,检测 限为0.004 mg/L,吸光度值的相对标准偏差为3.97%,迁移时间的相对标准偏差为2.99%,样品加标回收率为91.4%～116.6%。将该方法 与高效液相色谱法进行比较,两种方法测定结果的相对误差≤4%。所建立的检测醋酸氯己定含量的毛细管区带电泳法简单 、快速,适用于消毒剂样品的测定。     

基于非接触电导检测和在线富集技术快速灵敏检测土壤中速效磷

针对土壤中速效磷的快速检测需求,建立了基于非接触电导检测和场放大进样在线富集技术的毛细管电泳分离检测土壤中水溶性磷酸盐的分析方法。对影响分离检测效果的实验条件（电泳运行液组成、pH值、分离电压、进样电压和时间）进行了考察和优化。采用毛细管区带电泳模式,以35 mmol/L乙酸 - 2 mmol/L乙酸铵溶液为电泳运行液,负高压分离（－14 kV）和场放大进样（－11 kV × 10 s）,磷酸根离子在8 min内可获良好分离和灵敏检测,检出限为5 μg/L,线性范围为16～800 μg/L。研究表明放大进样在线富集技术使检测灵敏度得到显著提高,富集因子可达580倍。日内和日间相对标准偏差（RSD）小于5.0%。土壤中共存的常见无机阴离子（Cl－、SO2?442-、NO?33-）、有机基质和浸出液基体颜色不干扰速效磷的测定,表现出较强的抗干扰能力。该方法无需复杂的前处理即可直接进样分析,具有简单快速、灵敏高效、分析成本低的优点。对实际土壤样品和国标土壤样品中的速效磷进行检测,检测结果与标准方法一致。     

毛细管电泳法同时测定复方苦参注射液中三种生物碱含量

应用毛细管电泳法测定了复方苦参注射液中苦参碱、氧化苦参碱、槐定碱的含量。毛细管电泳条件为 :未涂层石英毛细管 ( 5 7cm× 5 0 μm i.d.) ,分离电压为1 2 .5 k V,0 .2 mol/ L Tris- 40 mmol/ L磷酸二氢钠 ( p H5 .5 0 ) - 2 0 %异丙醇为缓冲液 ,检测波长 2 0 0 nm,氢溴酸东莨菪碱为内标。结果表明 ,该法简便、快速、准确 ,重现性好。     

胶束毛细管电泳在线扫集技术同时分离测定穿心莲内酯和脱水穿心莲内酯的研究

采用胶束毛细管电泳在线扫集技术分离测定了中药穿心莲中脱水穿心莲内酯和穿心莲内酯.电泳条件:以20 mmol/L H3BO310 mmol/L NaH2PO4-50mmol/L SDS(含体积分数20%甲醇,pH 2.4)为电泳运行缓冲溶液,未涂层石英毛细管(58 cm×50 μm i.d.,有效长度为41.2 cm)为分离通道,重力进样,进样高度为11 cm,-20 kV恒压,检测波长为246 nm.富集倍数可以达到200倍以上.在5.70～91.20 mg/L,和3.96～31.68 mg/L范围内呈良好的线性关系,对两种内酯分别进行了定量分析.加标平均回收率脱水穿心莲内酯为100.80%,穿心莲内酯为98.06%.     

Electrophoretic separation with 2-mm inner diameter fused-silica microcolumn packed with quartz microncrystals and its application

The feasibility of a microcolumn electrophoresis technique was investigated with a 100 mm length, 2 mm I.D. fused-silica microcolumn packed with uniform quartz microncrystals prepared by hydrothermal synthesis. To evaluate the separation technique, tryptophan, phenylalanine and tyrosine were primarily separated by the microcolumn electrophoresis and detected at 216 nm without derivatization by an ordinary spectrophotometer. The separation conditions of the amino acids were optimized. With 1.5 mmol/L disodium phosphate buffer solution (pH 11.5) containing 25% (v/v) methanol and 10% (v/v) acetonitrile, the three amino acids were separated and the separation efficiency of tryptophan was 4.5 × 10⁴ plates/m. The limits of detection were 0.035, 0.22 and 0.20 μmol/L, respectively. The sample capacity of the electrophoretic microcolumn achieved 35 μL. The proposed method was used to determine these amino acids in compound amino acid injection samples without derivatization. For the simplicity and portability of the microcolumn electrophoresis, it is studied as one of the high-performance separation techniques for an in situ and real-time electrokinetic flow analysis system. For its high detection sensitivity and large sample capacity, it can be developed for preparative electrophoresis.     

电子墨水微胶囊及电泳显示原型器件的制备

TiO2 particles coated with polystyrene which were prepared via in situ polymerization and oil green dye were dispersed in tetrachloroethylene and xylene, the mixture came to be electrophoretic ink and was encapsulated in to microcapsules by complex coacervation from gelatin and a hydrolyzed copolymer of styrene and maleic anhydride(SMA). It was demonstrated that the membranes of the microcapsules were formed from nano sized coacervate droplets resulting from gelation and hydrolyzed SMA, which leads to a compact membrane structure. Microcapsules were characterized in terms of microstructure, morphologies by scanning electron microscopy(SEM). Electrophoretic display prototype was prepared by coating electrophoretic ink microcapsules slurry on ITO glass with nearly single layer and sealed by UV curable adhesires. The characters “Zheda” in Chinese was firstly displayed at a low volt 9 V D. C..     

Electrophoretic chip for high-fidelity fractionation of double-stranded DNA

We report the high fidelity, on-chip fractionation of selected segments from an electrophoretic flow of separated fragments. dsDNA fragments (10-330 base pairs (bp)) were initially separated using a 6.5 cm long channel with an electric field strength of 150 V/cm. As an example of the fractionation process, a target fragment of 20 bp was selected and extracted from the separation channel. The extraction was confirmed and evaluated by fluorescence imaging. High resolution and extraction fidelity were achieved by introducing new procedures for (i) extraction channel-blocking and (ii) segment transfer with cleaning. These procedures are necessary for the development of a practical, fully automated multitarget fractionation electrophoretic chip. A kind of CCD image processing method was introduced to monitor, control, and evaluate the procedure of fractionation. The resolution limits of the separation and extraction are discussed.     

Electrophoretic transport of latex particles in lipid nanotubes

Lipid vesicles can be connected by membrane nanotubes to build networks with promising bioanalytical properties. Here we characterize electrophoretic transport in such membrane tubes, with a particular eye to how their soft-material nature influences the intratube migration. In the absence of field, the tube radius is 110 +/- 26 nm, and it remains in this range during electrophoresis even though the applied electric field causes a slight decrease in the tube radius (approximately 6-11%). The electrophoretic velocity of the membrane wall (labeled with quantum dots) varies linearly with the field strength. Intratube migration is studied with latex spheres of radii 15, 50, 100, and 250 nm. The largest particle size does not enter the tube at fields strengths lower than 1250 V/m because the energy cost for expanding the tube around the particles is too high. The smaller particles migrate with essentially the same velocity as the membrane at low fields. Above 250 V/cm, the 15 nm particles exhibit an upward deviation from linear behavior and in fact migrate faster than in free solution whereas the 100 nm particles deviate downward. We propose that these nonlinear effects arise because of lipid adsorption to the particles (dominating for 15 nm particles) and a pistonlike compression of the solvent in front of the particles (dominating for 100 nm). As expected from such complexities, existing theories for a sphere migrating in a rigid-wall cylinder cannot explain our velocity results in lipid nanotubes.     

Electrophoretic migration of proteins in semidilute polymer solutions

We present a systematic study of the electrophoretic migration of 10-200 kDa protein fragments in dilute-polymer solutions using microfluidic chips. The electrophoretic mobility and dispersion of protein samples were measured in a series of monodisperse polydimethylacrylamide (PDMA) polymers of different molecular masses (243, 443, and 764 kDa, polydispersivity index <2) of varying concentration. The polymer solutions were characterized using rheometry. Prior to loading onto the microchip, the polymer solution was mixed with known concentrations of SDS (SDS) surfactant and a staining dye. SDS-denatured protein samples were electrokinetically injected, separated, and detected in the microchip using electric fields ranging from 100 to 300 V/cm. Our results show that the electrophoretic mobility of protein fragments decreases exponentially with the concentration c of the polymer solution. The mobility was found to decrease logarithmically with the molecular weight of the protein fragment. In addition, the mobility was found to be independent of the electric field in the separation channel. The dispersion is relatively independent of polymer concentration and it first increases with protein size and then decreases with a maximum at about 45 kDa. The resolution power of the device decreases with concentration of the PDMA solution but it is always better than 10% of the protein size. The protein migration does not seem to correspond to the Ogston or the reptation models. A semiempirical expression for mobility given by van Winkle fits the data very well.     

Electrophoretic properties of BSA-coated quantum dots

Low toxic InP/ZnS quantum dots (QDs), ZnS:Mn²⁺/ZnS nanocrystals and CdSe/ZnS nanoparticles were rendered water-dispersible by different ligand-exchange methods. Eventually, they were coated with bovine serum albumin (BSA) as a model protein. All particles were characterised by isotachophoresis (ITP), laser Doppler velocimetry (LDV) and agarose gel electrophoresis. It was found that the electrophoretic mobility and colloidal stability of ZnS:Mn²⁺/ZnS and CdSe/ZnS nanoparticles, which bore short-chain surface ligands, was primarily governed by charges on the nanoparticles, whereas InP/ZnS nanocrystals were not charged per se. BSA-coated nanoparticles showed lower electrophoretic mobility, which was attributed to their larger size and smaller overall charge. However, these particles were colloidally stable. This stability was probably caused by steric stabilisation of the BSA coating.     

Electrophoretic mobility of the polymer-like micelles of tetradecyldimethylamine oxide hemihydrochloride

Effects of the surfactant concentration C_d and the NaCl concentration C_s on the electrophoretic mobilities U of the well-characterized polymer-like micelles have been investigated by the electrophoretic light scattering, using tetradecyldimethylamine oxide hemihydrochloride (C14DMAO·1/2HCl). At the high ionic strength of 0.1 mol kg⁻¹ NaCl, the electrophoretic mobilities were independent of C_d (5 mM < C_d < 100 mM), despite the concentration-dependent micelle growth of the polymer-like micelles. This suggests that the electrophoretic mobility of the polymer-like micelle at high ionic strengths is independent of the contour length (i.e., the molecular weight), as found on linear polyelectrolytes. Somewhat surprisingly, the entanglements of the polymer-like micelles gave small effect on the electrophoretic mobilities in the examined range of the surfactant concentration above an overlap concentration. The mobilities of the polymer-like micelle decreased with √C_s in a single exponential manner in the range of C_s from 0.02 to 0.3 mol kg⁻¹. It is suggested that the cylinder model can be applied to the electrophoretic mobilities of the polymer-like micelles at high ionic strengths (i.e. a free-draining behavior), since the persistence length of the polymer-like micelle (20 nm) is much larger than the Debye length at high ionic strength.     

Electrophoretic methods for separation of nanoparticles

This article reviews progress in the application of electrophoretic techniques for the separation of nanoparticles. Numerous types of nanoparticles have recently been synthesised and integrated into different products and procedures. Consequently, analytical methods for the efficient characterisation of nanoparticles are now required. Several studies have revealed that gel electrophoresis can readily be used for separating nanoparticles according to their size or shape. However, many other studies focused on separation of nanoparticles by CE. In some cases nanoparticles could be separated by CZE, simply using pure buffer as the BGE. In other studies, buffer additives (most often SDS) were used, enabling fast separations of metallic nanoparticles by size. Other CE methods also allowed for separation of nanoparticle conjugates with biomolecules. Dielectrophoresis is yet another electrophoretic technique useful in separation and characterisation of nanoparticles; particularly nanotubes. Detection methods often used after electrophoretic separation include UV/Vis absorption and fluorescence spectroscopy. Examples of recent and relevant older reports are presented here. The authors conclude that electrophoretic methods for nanoanalysis can provide inexpensive and efficient tools for quality assurance and safety control; and as a consequence, they can augment transfer of nanotechnologies from research to industry.     

Electrophoretic deposited MWCNT composite graphite pencils and its uses to determine hyperin

A simple, fast, and effective method of fabricating electrochemical sensors using composite pencil graphite (CPG) lead modified with carboxylic multiwalled carbon nanotube (c-MWCNT) via electrophoretic deposition (EPD) has been developed. The EPD of c-MWCNT film on the CPG electrode (CPGE) was carried out at a constant applied potential of 25?V and deposition time of 1?min. The electrochemical performances of the modified CPGE, i.e., c-MWCNT/CPGE, in Fe(CN) ₆ ^4?/3? has been studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The c-MWCNT/CPGE has better current density, onset potentials, and charge transfer resistances than the CPGE. The c-MWCNT/CPGE has been successfully used to analyze hyperin in dry fruits of Acanthopanax sessiliflorus.     

Electrophoretic behaviour of calcium oxalate monohydrate in liquid mixtures

An experimental investigation on electrophoresis of calcium oxalate monohydrate in several liquid mixtures (methanol-, ethanol-, 2-propanol-, and methanol-acetonewater) is described.The electrophoretic transport is considered from the view-point of the Thermodynamics of Irreversible Processes. Linear relations have always been found between the mass flux and the applied electric field. The -potential of the interface C.O.M./liquid mixture has been estimated by using the classial theory of electrophoretic mobility of colloidal particles. The influence of the composition of the mixture on the electrophoretic coefficient has been discussed on the basis of the variation of -potential, viscosity and dielectric constant with the molar fraction of alcohol for binary mixtures and acetone for ternary mixtures. The concentration dependence of the electrophoretic coefficient is found to be linear only in the latter case.