毛细管电泳及芯片毛细管电泳的电容耦合非接触电导检测

综述了毛细管电泳(CE)及芯片毛细管电泳(MCE)的电容耦合非接触电导检测(Capacitively Coupled Contactless Conductivity detection,C4D)的研究状况;并分别对其装置、检测的影响因素及其应用进行了评述。引用文献81篇。     

毛细管电泳非接触电导检测技术的新发展

毛细管电泳非接触电导检测(CE-CCD)是近年来发展迅速的一种检测技术。本文介绍了非接触式电导检测(CCD)的发展概况,着重阐述了CCD的原理、组成及应用情况。     

毛细管电泳非接触电导分离检测金属氧化物纳米粒子

采用毛细管电泳非接触电导检测技术,以碳酸钠-碳酸氢钠为缓冲体系,同时分离测定了纳米二氧化钛和三氧化二铝两种金属氧化物的悬浮粒子.考察了缓冲溶液种类、浓度及pH对分离效果的影响,探讨了激发频率、激发电压对检测信号信噪比的影响.在最佳分离检测条件下,不同粒径的二氧化钛和三氧化二铝悬浮粒子在8 min内可实现完全分离.所选择的最佳条件为:① pH 10.5缓冲溶液为5 mmol·L-1碳酸钠和碳酸氢钠混合溶液;②分离电压20 kV;③进样条件20 kV,6 s;④激发频率460 kHz;⑤交流激发电压4 V(给出最高的S/N比值).     

毛细管电泳无接触电导检测研究进展

毛细管电泳(CE)电导检测(CD)是相对较灵敏和仪器结构简单的一项溶液分析技术,尤其是对于无生色团的无机离子分析更具有突出优势,因此,CE-CD技术近年来得到了较快发展[1],并已推出商品化的毛细管电泳电导检测器[2]。但CE和CD的偶联目前还存在如下几个问题:第一,加工适合于毛细管     

毛细管电泳非接触电导检测法研究电渗流峰变化规律

采用自行研制的非接触电导检测器,结合毛细管电泳技术,以10 mmol/L的2-N-吗啡啉乙磺酸(MES)/L-组氨酸(L-His)为缓冲溶液,系统研究了缓冲溶液浓度、pH值、样品浓度对电渗流峰的变化规律。结果表明:随着样品KCl溶液的浓度的减小,电渗流峰出现由正峰逐渐变为负峰的现象,并结合非接触电导检测原理、L-His的特性和质子平衡方程进行了的解释。     

非水介质毛细管电泳电导法检测盐酸胺碘酮

采用非水介质毛细管电泳电导检测法对盐酸胺碘酮进行检测。探讨了缓冲溶液的种类、pH和浓度、分离电压、进样时间、进样高度等因素对检测效果的影响,建立了测定盐酸胺碘酮的新方法。用乙醇作为非水介质,在30mmol L三羟甲基氨基甲烷 15mmol L柠檬酸(pH6.90)运行缓冲溶液中,盐酸胺碘酮在5～200mg L范围内的线性回归方程为y=74.94x-7.83,r=0 999。检出限(S N=3)为0.5mg L,样品回收率为98.9%。适用于含盐酸胺碘酮的药剂的分析。     

芯片毛细管电泳非接触电导法快速测定葡萄糖氯化钠的含量

报道了一种芯片毛细管电泳-非接触电导法,用于快速测定葡萄糖氯化钠注射液中两种药物的含量。实验考察了运行缓冲液pH值和分离电压对组分分离的影响,以及检测器激励频率对组分信号响应和灵敏度的影响。确定以20 mmol/L硼酸缓冲液(pH 9.6)为分离介质,分离电压为1 200 V;最佳激励频率为70kHz。在上述条件下,两种成分(葡萄糖和Na+)可在60 s内实现有效分离。Na+和葡萄糖的线性响应范围分别为20～1 000μmol/L和50～5 000μmol/L(r≥0.992);按信噪比(S/N)为3∶1计算检出限分别为8.2μmol/L和26.7μmol/L。两个组分的回收率分别为95%～99%和97%～104%,相对标准偏差(RSDs)均小于4.0%。该文首次报道了葡萄糖和氯化钠两种常见药物成分的同时测定。方法简便、快速、准确度高、稳定性好,用于注射剂含量的测定,结果满意。     

混合稀土离子的毛细管电泳电导法分离检测

采用高效毛细管电泳电导检测法分离检测了稀土离子。以醋酸-醋酸钠为背景电解质,4-吗啉乙磺酸（MES）为络合剂,在24kV的高压下,7种稀土离子得到子较好的分离。考察了背景电解质的pH和浓度,络合剂的浓度,分离电压等对稀土离子分离的影响。在选定的实验条件下,7种烯土离子在10min内守成分离检测。     

毛细管电泳电容耦合非接触电导法测定连翘中三萜酸

建立了测定连翘中三萜酸(齐墩果酸、熊果酸、白桦脂酸)的毛细管电泳电容耦合非接触电导分析方法。通过对H_3BO_3浓度、β-环糊精(β-CD)浓度、分离电压、进样时间等因素的优化,确定了最佳实验条件。结果表明,在60 mmol/L H_3BO_3-6 mmol/Lβ-CD的背景电解质中,且分离电压为15 kV,5 kPa压力进样4 s的条件下,三萜酸得以分离。三萜酸质量浓度在5. 0～80. 0μg/mL范围内呈现良好的线性关系,线性相关系数(R~2)均大于0. 9935,方法的检出限在1. 04～1. 43μg/mL之间,迁移时间和峰面积的相对标准偏差分别为0. 02%～0. 04%,3. 5%～4. 4%。方法应用于河南栾川老翘中的三萜酸的回收率测试,三萜酸的加标回收率为88. 1%～94. 1%。方法可应用于连翘样品中的三萜酸分析。     

毛细管电泳非接触电导检测分离测定水杨酸及其羟基化产物

利用自组装的毛细管电泳非接触电导检测装置建立了水杨酸（SA,羟基自由基捕获剂）及其羟基化产物2,3-二羟基苯甲酸（2,3-DHBA）和2,5-二羟基苯甲酸（2,5-DHBA）的分离测定方法。在最佳条件下10min内即可完成分离,其线性范围为0．03～15．0mg·L^-1L^-1,检出限（S／N=3）为0．01mg·L^-1,对0．7mg·L^-1混合溶液进行测定,SA、2,3-DHBA和2,5-DHBA峰面积的相对标准偏差（n=8）依次为2.9％,3．2％,3．6％。     

Monosaccharide profiling of glycoproteins by capillary electrophoresis with contactless conductivity detection

Saccharides form one of the major constituents of biological macromolecules in living organisms. Many biological processes including protein folding, stability, immune response and receptor activation are regulated by glycosylation. In this work, we optimized a capillary electrophoresis method with capacitively coupled contactless conductivity detection for the separation of eight monosaccharides commonly found in glycoproteins, namely D-glucose, D-galactose, D-mannose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-fucose, N-acetylneuraminic acid, and D-xylose. A highly alkaline solution of 50 mM sodium hydroxide, 22.5 mM disodium phosphate, and 0.2 mM CTAB (pH 12.4) was used as a background electrolyte in a 10 µm id capillary. To achieve baseline separation of all analytes, a counter-directional pressure of –270 kPa was applied during the separation. The limits of detection of our method were below 7 µg/ml (i.e., 1.5 pg or 1 mg/g protein) and the limits of quantification were below 22 µg/ml (i.e., 5 pg or 3 mg/g protein). As a proof of concept of our methodology, we performed an analysis of monosaccharides released from fetuin glycoprotein by acid hydrolysis. The results show that, when combined with an appropriate pre-concentration technique, the developed method can be used as a monosaccharide profiling tool in glycoproteomics and complement the routinely used LC-MS/MS analysis.     

Determination of vitamin C and preservatives in beverages by conventional capillary electrophoresis and microchip electrophoresis with capacitively coupled contactless conductivity detection

The separation and detection of commonly used preservatives (benzoate, sorbate) and vitamin C by both conventional CE and microchip electrophoresis with capacitively coupled contactless conductivity detection is presented. The separation was optimized by adjusting the pH-value of the buffer and the use of hydroxypropyl-beta-CD (HP-beta-CD) and CTAB as additives. For conventional CE, optimal separation conditions were achieved in a histidine/tartrate buffer at pH 6.5, containing 0.025% HP-beta-CD and 0.1 mM CTAB. LOD ranged from 0.5 to 3 mg/L (S/N = 3) and the RSDs for migration time and peak area were less than 0.1 and 2%, respectively. A considerable reduction of analysis time can be accomplished by using microchip electrophoresis without significant loss in sensitivity under optimal separation conditions. A histidine/tartrate buffer at pH 6.5, incorporating 0.06% HP-beta-CD and 0.25 mM CTAB, gave detection limits ranging between 3 and 10 mg/L and satisfactory reproducibilities of < or =0.4% for the migration time and < or =3.5% for the peak area. The methods developed are useful for the quantitative determination of food additives in real samples such as soft drinks and vitamin C tablets.     

Simultaneous determination of atenolol and amiloride in pharmaceutical preparations by capillary zone electrophoresis with capacitively coupled contactless conductivity detection

Capillary zone electrophoresis coupled with a capacitively coupled contactless conductivity detector (CE‐C⁴D) has been employed for the determination of atenolol and amiloride in pharmaceutical formulations. Acetic acid (150 mm ) was used as background electrolyte. The influence of several factors (detector excitation voltage and frequency, buffer concentration, applied voltage, capillary temperature and injection time) was studied. Non‐UV‐absorbing L‐valine was used as internal standard; the analytes were all separated in less than 7 min. The separation was carried out in normal polarity mode at 28°C, 25 kV and using hydrodynamic injection (25 s). The separation was effected in an uncoated fused‐silica capillary (75 μm, i.d. × 52 cm). The CE‐C⁴D method was validated with respect to linearity, limit of detection and quantification, accuracy, precision and selectivity. Calibration curves were linear over the range 5–250 μg/mL for the studied analytes. The relative standard deviations of intra‐ and inter‐day migration times and corrected peak areas were less than 6.0%. The method showed good precision and accuracy and was successfully applied to the simultaneous determination of atenolol and amiloride in different pharmaceutical tablet formulations. Copyright © 2010 John Wiley & Sons, Ltd.     

多材料3D打印技术制作用于毛细管电泳的非接触电导/激光诱导荧光二合一检测池

利用多材料3D打印技术研制了用于毛细管电泳(CE)的二合一检测池,实现了电容耦合非接触电导(C4D)与共聚焦激光诱导荧光(LIF)两种检测方法在毛细管柱上同一位置同时检测.3D打印的检测池采用了导电的复合聚乳酸(PLA)材料制作C4 D的屏蔽层,采用普通的绝缘PLA材料支撑C4 D金属管电极并隔离屏蔽层.两根金属管电极...     

Determination of tobramycin in human serum by capillary electrophoresis with contactless conductivity detection

A study on the determination of the antibiotic tobramycin by CE with capacitively coupled contactless conductivity detection is presented. This method enabled the direct quantification of the non-UV-absorbing species without incurring the disadvantages of the indirect approaches which would be needed for optical detection. The separation of tobramycin from inorganic cations present in serum samples was achieved by optimizing the composition of the acetic acid buffer. Field-amplified sample stacking was employed to enhance the sensitivity of the method and a detection limit of 50 microg/L (S/N = 3) was reached. The RSDs obtained for migration time and peak area using kanamycin B as internal standard were typically 0.12 and 4%, respectively. The newly developed method was validated by measuring the concentration of tobramycin in serum standards containing typical therapeutic concentrations of 2 and 10 mg/L. The recoveries were 96 and 97% for the two concentrations, respectively.     

Determination of heavy metal ions by microchip capillary electrophoresis coupled with contactless conductivity detection

An integrated detection circuitry based on a lock-in amplifier was designed for contactless conductivity determination of heavy metals. Combined with a simple-structure electrophoresis microchip, the detection system is successfully utilized for the separation and determination of various heavy metals. The influences of the running buffer and detection conditions on the response of the detector have been investigated. Six millimole 2-morpholinoethanesulfonic acid + histidine were selected as buffer for its stable baseline and high sensitivity. The best signals were recorded with a frequency of 38 kHz and 20 V(pp). The results showed that Mn(2+), Cd(2+), Co(2+), and Cu(2+) can be successfully separated and detected within 100 s by our system. The detection limits for five heavy metals (Mn(2+), Pb(2+), Cd(2+), Co(2+), and Cu(2+)) were determined to range from about 0.7 to 5.4 μM. This microchip system performs a crucial step toward the realization of a simple, inexpensive, and portable analytical device for metal analysis.     

Enantiomeric separation of some common controlled stimulants by capillary electrophoresis with contactless conductivity detection

CE methods with capacitively coupled contactless conductivity detection (C⁴D) were developed for the enantiomeric separation of the following stimulants: amphetamine (AP), methamphetamine (MA), ephedrine (EP), pseudoephedrine (PE), norephedrine (NE) and norpseudoephedrine (NPE). Acetic acid (pH 2.5 and 2.8) was found to be the optimal background electrolyte for the CE‐C⁴D system. The chiral selectors, carboxymethyl‐β‐cyclodextrin (CMBCD), heptakis(2,6‐di‐O‐methyl)‐β‐cyclodextrin (DMBCD) and chiral crown ether (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid (18C6H₄), were investigated for their enantioseparation properties in the BGE. The use of either a single or a combination of two chiral selectors was chosen to obtain optimal condition of enantiomeric selectivity. Enantiomeric separation of AP and MA was achieved using the single chiral selector CMBCD and (hydroxypropyl)methyl cellulose (HPMC) as the modifier. A combination of the two chiral selectors, CMBCD and DMBCD and HPMC as the modifier, was required for enantiomeric separation of EP and PE. In addition, a combination of DMBCD and 18C6H₄ was successfully applied for the enantiomeric separation of NE and NPE. The detection limits of the enantiomers were found to be in the range of 2.3–5.7 μmol/L. Good precisions of migration time and peak area were obtained. The developed CE‐C⁴D method was successfully applied to urine samples of athletes for the identification of enantiomers of the detected stimulants.     

Pressure-assisted capillary electrophoresis for cation separations using a sequential injection analysis manifold and contactless conductivity detection

Pressure assisted capillary electrophoresis in capillaries with internal diameters of 10 μm was found possible without significant penalty in terms of separation efficiency and sensitivity when using contactless conductivity detection. A sequential injection analysis manifold consisting of a syringe pump and valves was used to impose a hydrodynamic flow in the separation of some inorganic as well as organic cations. It is demonstrated that the approach may be used to optimize analysis time by superimposing a hydrodynamic flow parallel to the electrokinetic motion. It is also possible to improve the separation by using the forced flow to maintain the analytes in the capillary, and thus the separation field, for longer times. The use of the syringe pump allows flexible and precise control of the pressure, so that it is possible to impose pressure steps during the separation. The use of this was demonstrated for the speeding up of late peaks, or forcing repeated passage of the sample plug through the capillary in order to increase separation.     

液液萃取-场放大进样-毛细管电泳非接触式电导分离检测酱油中的安赛蜜

采用场放大进样(FASI)-毛细管电泳非接触式电导检测法(CE-C⁴D),结合液液萃取(LLE)的样品净化预处理技术,分离检测了酱油中人工合成甜味剂安赛蜜。酱油样品经酸化后,用乙酸乙酯作为萃取剂,成功地消除了酱油中含有的大量无机盐等复杂基体对微量安赛蜜的干扰。实验对影响LLE萃取效率和FASI-CE-C⁴D分离检测的关键因素进行了讨论,特别是对样品净化前处理过程中萃取剂及用量、样品酸化pH值、萃取时间、萃取温度等条件进行了优化。结果表明,酱油中的安赛蜜可获得良好分离和灵敏检测,检出限和定量限分别为0.15 mg/kg和0.48 mg/kg。对市售酱油样品进行安赛蜜的加标回收测定,得到加标回收率为92.3%～108.1%,相对标准偏差<8.0%。该法具有简单快速、灵敏高效、分析成本低的优点,能满足酱油中安赛蜜的分析检测要求。     

Study on the effects of electrolytes and solvents in the determination of quaternary ammonium ions by nonaqueous capillary electrophoresis with contactless conductivity detection

A study on the separation of lipophilic quaternary ammonium cations in NACE coupled with contactless conductivity detection (NACE‐C⁴D) is presented. The suitability of different salts dissolved in various organic solvents as running electrolytes in NACE‐C⁴D was investigated. A solvent mixture of methanol/acetonitrile at a ratio of 90%:10% v/v showed the best results. Deoxycholic acid sodium salt as BGE was found to provide exceptional high stability with low baseline noise that leads to highest S/N ratios for the target analytes among all BGEs tested. Under the optimum conditions, capillaries with different internal diameters were examined and an id of 50 μm was found to give best detection sensitivity. The proposed method was validated and showed good linearity in the range from 2.5 to 200 μM, low limits of detection (0.1–0.7 μM) and acceptable reproducibility of peak area (intraday RSD 0.1–0.7%, n = 3; interday RSD 5.9–9.4%, n = 3).