Determination of hesperidin and synephrine in Pericarpium Citri Reticulatae by capillary electrophoresis with electrochemical detection

A method based on capillary electrophoresis with electrochemical detection (CE-ED) has been developed for the determination of hesperidin (HP) and synephrine (SP) in the Chinese traditional herbal drug, Pericarpium Citri Reticulatae, the dried rind of the ripe fruits of Citrus reticulata Blanco (mandarin orange). The effects of some important factors such as the acidity and concentration of running buffer, separation voltage, and detection potential were investigated to determine the optimum conditions. The working electrode was a 300 microm diameter carbon disc electrode positioned opposite the outlet of the capillary. Both analytes could be well separated within 5 min in a 40 cm long capillary at a separation voltage of 12 kV in 50 mmol L(-1) borate buffer (pH 9.0). Excellent linearity was observed for the dependence of peak current on analyte concentration in the range from 2.5 x 10(-6) to 1.0 x 10(-3) mol L(-1) for SP and from 5.0 x 10(-6) to 1.0 x 10(-3) mol L(-1) for HP. The detection limits (S/N=3) for SP and HP were 4.96 x 10(-7) mol L(-1) and 6.54 x 10(-7) mol L(-1), respectively. This method has been successfully applied for the analysis of real samples, with satisfactory results.     

胶束电动毛细管色谱安培检测中药马齿苋中多巴胺和去甲肾上腺素

建立了胶束电动毛细管色谱结合电化学安培检测同时分析中药马齿苋中多巴胺和去甲肾上腺素的方法。考察了缓冲液的浓度、pH值、十二烷基硫酸钠(SDS)浓度以及工作电极电势对分离检测的影响。在优化的条件下,多巴胺和去甲肾上腺素在1.0×10-6～5 0×10-4mol/L范围内有良好线性,浓度检测限(S/N=3)分别为8 7×10-7mol/L和4 2×10-7mol/L,质量检测限分别为1 45fmol和0 41fmol。该方法组分定性可靠,不需要衍生处理,选择性好。将该法应用于中药马齿苋样品的分析,获得了较好的结果。     

毛细管胶束电动色谱法分析PTH氨基酸

建立了用毛细管胶束电动色谱法（MEKC）分离19种PTH氨基酸的方法,并探讨了电压、pH值、温度、胶束浓度对氨基酸迁移时间的影响。方法具有速度快、灵敏度高、样品用量少的优点。     

Determination of Nicotine in Tobacco by Capillary Electrophoresis with Electrochemical Detection

A sensitive, simple and low-cost method based on capillary electrophoresis(CE) with electrochemical(EC) detection at a carbon fiber microdisk electrode(CFE) was developed for the determination of nicotine. Effects of detection potential, concentration and pH value of the phosphate buffer, and injection time as well as separation voltage were investigated. Under the optimized conditions: a detection potential of 1.20 V, 40 mmol/L phosphate buffer(pH 2.0), a sample injection time of 10 s at 10 kV and a separation voltage of 16 kV, the linear range obtained was from 5.0×10^-7 mol/L to 1.0×10^-4 mol/L with a correlation coefficient of 0.9989 and the limit of detection(LOD, S/N=3) obtained was 5.0×10^-8 mol/L. The method was also used to determine the nicotine in cigarettes. Nicotine amount ranged from 0.211 mg/g to 0.583 mg/g in the pipe tobacco of seven brands of cigarette and the amount in one cigarette varied from 0.136 mg/cigarette to 0.428 mg/cigarette.     

黄芩及其制剂中黄芩素和黄芩甙的

用毛细管区带电泳 -电化学检测法测定了黄芩及其制剂中黄芩素和黄芩甙的含量。研究了电极电位、电解液酸度和浓度、电泳电压及进样时间等对电泳的影响 ,得到了较为优化的测定条件。以直径为300μm的碳圆盘电极为检测电极 ,电极电位为0.90V(vsSCE) ,在100mmol/L硼酸盐缓冲液(pH9.0)中 ,上述两组分在8min内完全分离。黄芩素和黄芩甙浓度与电泳峰电流分别在5.0×10 -7～1.0×10 -3mol/L和1.0×10 -6～1.0×10 -3mol/L范围内呈良好线性 ,检出限分别为2.24×10 -7mol/L和5.48×10 -7mol/L。7次测定分别含5.0×10 -4mol/L黄芩素和黄芩甙试样溶液 ,峰高的相对标准偏差分别为3.53%和4.03%。     

Determination of antioxidants in cosmetics by micellar electrokinetic capillary chromatography with electrochemical detection

A new and efficient method for the determination of antioxidants [Propyl gallate (PG), tert-butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT)] in cosmetics has been established by using micellar electrokinetic capillary chromatography with electrochemical detection (MECC-ED). Under the optimum conditions of the method, all analytes were successfully separated within 13 min at the separation voltage of 18 kV in a 20 mmol/L borate running buffer (pH 7.4) containing 25 mmol/L sodium dodecyl sulfate. The excellent linearity was obtained in the concentration range from 5.0 x 10(-4) to 2.0 x 10(-6) mol/L and the detection limits (S/N = 3) of PG, TBHQ, BHA, and BHT range from 3 x 10(-7) to 3 x 10(-6) mol/L.     

Separation and determination of the macrolide antibiotics (erythromycin, spiramycin and oleandomycin) by capillary electrophoresis coupled with fast reductive voltammetric detection

Separation and determination of erythromycin, spiramycin and oleandomycin by capillary zone electrophoresis coupled with fast reductive voltammetric detection using an Hg-film electrode was investigated in a simple aqueous phosphate buffer system. The influence of pH, concentration of phosphate, applied voltage, capillary length and dimension on the separation was examined and optimized. The entire separation of erythromycin, spiramycin, and oleandomycin was achieved in a 0.2 mol/L phosphate buffer system without organic modifiers. The electrochemical detection parameters, such as electrode material, applied waveform, scan rate, preconcentration potentials and preconcentration times, were investigated and discussed. This approach provides high separation efficiency and high sensitivity for all compounds, with detection limits (3 x peak-to-peak baseline noise) of 7.5 x 10(-8) mol/L for spiramycin, and 3 x 10(-7) mol/ L for erythromycin and oleandomycin. The calibration plot of peak areas for each separated peak vs. concentration of analyte was found to be linear over three orders of magnitude.     

毛细管区带电泳电化学检测法测定药物及果汁中芦丁和L-抗坏血酸

用毛细管区带电泳-电化学检测法同时测定复方芦丁片及果汁中芦丁和L-抗坏血酸的含量.研究了电极电位、电解液浓度和酸度、电泳电压及进样时间等对电泳的影响,得到了较为优化的测定条件.以直径为300μm的碳圆盘电极为检测电极,电极电位为1.0V(vs.SCE),在25mmol/L硼砂-50mmol/LNaH₂PO₄(pH8.0)运行缓冲液中,上述两组分在12min内完全分离.芦丁和L-抗坏血酸浓度分别在1.0×10^-6～2.5×10^-4和5.0×10^-6～2.5×10^-3mol/L范围内与电泳峰电流呈现良好线性关系,检测下限分别为8.0×10^-7和3.3×10^-6mol/L.9次测定含5.0×10^-5mol/L芦丁和2.5×10^-4mol/LL-抗坏血酸的试样溶液,峰高的相对标准偏差分别为2.85%和1.65%,5次测得的平均回收率分别为97.73%和99.68%.     

微乳电动毛细管色谱法分离检测酱油中的氯丙醇

建立了微乳电动毛细管色谱分离3种氯丙醇的方法。以十二烷基硫酸钠(SDS)作为表面活性剂,系统考察了pH值、缓冲溶液类型和浓度、SDS浓度、助表面活性剂浓度、油相浓度、温度和运行电压对3-氯-1,2-丙二醇(3-MCPD),1,3-二氯-2-丙醇(1,3-DCP),2,3-二氯-1-丙醇(2,3-DCP)分离的影响。结果表明,最佳微乳缓冲液为1%(V/V)正庚烷,100 mmol/L SDS,10%(V/V)正丁醇和8 mmol/L磷酸二氢钠-硼砂溶液(pH 8.50),检测波长为192 nm,温度20℃,分离电压为15 kV。3种氯丙醇的线性范围为2.0×10-6～3.2×10-5 mol/L,相关系数大于0.996,检出限(S/N=3)为0.95～1.9μmol/L。酱油样品经乙醚液液萃取,萃取平均回收率为93.2%～103.0%,相对标准偏差小于6.5%。本方法应用于实际样品和加标后样品中三氯丙醇的检测,结果满意。     

肌肽类生物活性肽的毛细管电泳在线富集技术

建立了毛细管区带电泳(CZE)在线富集3种肌肽类活性肽(肌肽、鹅肌肽和高肌肽)的两种简便有效的方法。一种是大体积进样反向压力排除基体富集（LVSRP）技术,即通过流体动力学进样,在不改变电源极性的条件下,利用反向压力排除样品基体,电堆积富集后进行CZE分离;另一种是大体积进样电渗流排除基体富集（LVSEP）技术,即通过流体动力学进样,于运行缓冲液中加入溴化十六烷基三甲基铵(CTAB)动态修饰毛细管表面,通过电渗流排除样品基体,改变电源极性后进行CZE分离。与常规CZE相比,LVSRP技术和LVSEP技术使检测灵敏度提高了40~60倍。对影响两种富集过程的一些因素进行了研究,在最优富集条件下考察本方法的线性范围为0.080~5.0 μmol/L。对3种生物活性肽的检测限(S/N=3)分别为LVSRP 41~58 nmol/L,LVSEP 35~43 nmol/L。     

毛细管电泳电致化学发光检测血浆中布比卡因

布比卡因是一种外科局部麻醉剂,使用过量会导致中枢神经系统和心脏血管系统中毒^[1],可引起心脏停博.高效液相色谱和毛细管电泳(CE)^[2]是该药常用的检测方法.     

Electrochemical Detection of Methimazole by Capillary Electrophoresis at a Carbon Fiber Microdisk Electrode

We developed a sensitive, simple and low cost method to determine methimazole based on capillary electrophoresis with electrochemical detection (CE‐EC) at a carbon fiber microdisk electrode (CFE). We investigated the effects of detection potential, the concentration and pH value of the phosphate buffer, and injection time as well as separation voltage on the detection of methimazole. Under the optimized conditions: the detection potential at 1.30 V, 10 mmol/L phosphate buffer (pH 7.0), injection time 30 s at a height of 20 centimeter and separation voltage at 15 kV, the linear range was obtained from 1.0×10^?7 to 2.0×10^?4 mol/L, covering 3 orders of magnitude with a correlation coefficient of 0.9995. The LOD (S/N=3) obtained was 5.0×10^?8 mol/L. The RSD of migration time and peak current for 2.0×10^?4 mol/L methimazole was 1.04% and 1.54% (n=10), respectively. The method was also used to analyze methimazole tablets and human urine sample.     

Determination of scopolamine, atropine and anisodamine in Flos daturae by capillary electrophoresis.

A capillary electrophoresis method was developed for the separation and determination of tropane alkaloids in Flos daturae plants. Separation was performed on a fused silica capillary(42.1 cm x 50 microm i.d.) at an applied voltage of 20 kV. Scopolamine, atropine and anisodamine were well separated in the buffer of 50 mmol/L phosphate buffer (pH 5.0) containing 20% (v/v) tetrahydrofuran (THF). Beer's law was obeyed in the range of concentration of 2.4-21.8 microg/mL for scopolamine, 4.0-36.0 microg/mL for atropine and 2.6-23.7 microg/mL for anisodamine, respectively, and the correlation coefficients were over 0.999 (n = 6). The developed method was applied for the analysis of herb samples.     

Determination of clozapine by capillary zone electrophoresis following end-column amperometric detection with simplified capillary/electrode alignment

Capillary zone electrophoresis was employed for the determination of clozapine using an end-column amperometric detection at a carbon fiber array microdisk electrode with simplified capillary/electrode alignment. The optimum conditions of separation and detection are: Britton-Robinson buffer, pH 2.0 (1.3 x 10(-2) mol/L total concentration of acids, 3.2 x 10(-3) mol/L NaOH), 15 kV for separation voltage, 5 kV and 10 s for injection voltage and injection time, respectively. The limit of detection is 4.2 x 10(-7) mol/L or 1.2 fmole (signal to noise, S/N = 2). The relative standard deviation is 1.4% for the migration time and 2.5% for the electrophoretic peak current. The method was applied to the determination of clozapine in human blood. The recovery of the method is between 94-104%.     

黑火药余烬中无机阴离子的毛细管电泳方法研究

 发展了一种用于黑火药余烬中无机阴离子测定的毛细管电泳分析方法。对缓冲溶液的组成及pH值、电渗流改性剂的浓度以及分离电压等条件进行了研究。选定条件 :分离电压为 - 2 0kV ,缓冲溶液为 5 0mmol/L的Na2 CrO4(pH 8 2 0 ) ,电渗流改性剂为 0 5mmol/L的溴化十六烷基三甲基铵 (CTAB) ,检测波长为 2 5 4nm。在上述条件下 ,5种阴离子在 4min内可完全分离。各组分迁移时间和峰面积的相对标准偏差 (RSD)分别为 0 17%～1 4 0 %和 3 9%～ 5 0 % ,最低检测限为 5 0 μmol/L～ 10 0 μmol/L。     

3-苯基乳酸的手性毛细管电泳拆分

考察了环糊精种类、环糊精浓度、缓冲溶液pH、分离电压、温度等因素对3-苯基乳酸手性分离的影响,并对分离条件进行了优化。结果表明,采用区带毛细管电泳技术,以0.03 mol/L的羟丙基-β-环糊精为手性选择剂,0.1 mol/L的磷酸缓冲溶液(pH 5.5)为电泳缓冲溶液,26 kV的分离电压,在25 ℃下可使3-苯基乳酸对映体达到基线分离,分离度为1.51。     

肝糖选择剂-毛细管电泳手性拆分盐酸度洛西汀对映体及分离机制

以肝糖为毛细管电泳手性选择剂,对盐酸度洛西汀对映体的分离进行研究,建立了拆分方法.考察了手性选择剂浓度、运行缓冲液的离子强度、pH值及分离电压对手性分离的影响.在3.0% (m/V)肝糖、50 mmol/L Tris-H3PO4(pH 3.0)的运行缓冲液中,分离电压25 kV时,盐酸度洛西汀两对映体分离度达1.84.对分离机制进行了初步探讨.     

Development of a capillary electrophoresis method for the enantioselective estimation of primaquine in pharmaceutical formulations

A capillary electrophoresis (CE) method has been developed that allows the separation and estimation of primaquine enantiomers using hydroxypropyl-gamma-cyclodextrin (HP-gamma -CD) as a chiral selector. The influence of chemical and instrumental parameters on the separation, such as type and concentration of CD, buffer concentration, buffer pH, applied voltage, capillary temperature, and injection time, were investigated. Good separation of the racemic mixture of primaquine was achieved using a fused-silica capillary (52.5 cm effective length x 50 microm id) and a background electrolyte composed of tris-phosphate buffer solution (50 mM, pH 2.5) containing 15 mM HP-gamma-CD as a chiral selector. The recommended applied voltage, capillary temperature, and injection time were 15 kV, 25 degrees C, and 6 s, respectively. Within-day and interday reproducibility of peak area and migration time gave relative standard deviation values ranging from 1.05-3.30%. Good recoveries (range of 96.8-104.9%) were obtained from the determination of placebos that were spiked with 0.25-1.00 mg/L primaquine. The proposed CE method was successfully applied to the assay of primaquine diphosphate in pharmaceutical formulations (tablets).     

Direct tris(2,2'-bipyridyl)ruthenium (II) electrochemiluminescence detection of polyamines separated by capillary electrophoresis

Capillary electrophoresis (CE) with tris(2,2'-bipyridyl) ruthenium (II) (Ru(bpy)3(2+)) electrochemiluminescence (ECL) detection technique was developed for the analysis of four polyamines (putrescine (Put), cadaverine (Cad), spermidine (Spd), and spermine (Spm)) analysis. The four polyamines contain different amine groups, which have different ECL activity. There are several parameters which influence the resolution and ECL peak intensities, including the buffer pH and concentrations, separation voltage, sample injection, electrode materials, and Ru(bpy)3(2+) concentrations. Polyamines are separated by capillary zone electrophoresis in an uncoated fused-silica capillary (50 cmx25 micro m (ID) filled with acidic phosphate buffer (200 mmol/L phosphate, pH 2.0) - 1mol/L phosphoric acid (9:1 v/v) and a separation voltage of 5 kV (25 micro A), with end-column Ru(bpy)3(2+) ECL detection. A 5 mmol/L Ru(bpy)3(2+) solution plus 200 mmol/L phosphate buffer (pH 11.0) is added into the reagent reservoir. The calibration curve is linear over a concentration range of two or three orders of magnitude for the polyamines. The analysis time is less than 25 min. Detection limits for Put and Cad are 1.9x10(-7) mol/L and 7.6x10(-9) mol/L for Spd and Spm, respectively. Intraday and interday relative standard deviations of ECL peak intensities are less than 8%. The main advantages of this CE-ECL detection technique for polyamines analysis presented herein are the omission of chemical derivatization of the analytes and the high selectivity.     

毛细管胶束电动色谱法分离测定中药半枝莲中的7种有效成分

建立了毛细管胶束电动色谱同时分析检测中药半枝莲药材及其膏剂中黄芩素、柚皮素、汉黄芩素、野黄芩苷、芹菜素、木犀草素和原儿茶酸7种有效成分的方法。半枝莲样品中7种有效成分经甲醇超声提取。实验考察了运行缓冲溶液的pH值和浓度、添加剂、检测波长、分离电压和进样时间等重要参数对目标物分离的影响。得到的优化条件为: 运行缓冲液50 mmol/L硼砂-0.20 mol/L硼酸溶液(pH 8.4),含8.5 mmol/L十二烷基硫酸钠(SDS),分离电压25 kV,检测波长260 nm和335 nm。在此条件下,7种组分于12 min内达到基线分离。各组分在8×10~6～3.2×10~4mol/L范围内呈良好的线性关系,相关系数(r2)为0.9965～0.9999;检出限为7.0×10~8～2.0×10~6mol/L;回收率均大于85%。该方法提取简便、准确可靠、重复性好、灵敏度高,可以用于中药半枝莲中7种有效成分的定量检测。