毛细管电泳法分离测定芦丁、槲皮素和连翘苷

用毛细管电泳紫外检测法同时测定了芦丁、槲皮素和连翘苷，研究了各种条件的影响，得到了优化的实验条件，在20mmol/L的Na2B4O7(H3B03调节至pH8．40)-30mmol/L十二烷基硫酸钠-10％乙腈(1 9)的缓冲溶液中，分离电压为12kV时，芦丁、槲皮素和连翘苷在10min内得到了良好的分离，检测波长为254nm，芦丁、槲皮素和连翘苷分别在0．01-1．0mg/mL，0．01-1．0mg／mL和0．05-1．0mg/mL质量浓度范围内与电泳峰高呈现良好线性关系，检测下限分别为0．005mg/mL，0．005mg/mL和0．01mg／mL，应用于实际样品的测定。     

毛细管电泳安培法测定脂可平胶囊中的姜黄素

采用毛细管电泳柱端安培检测对脂可平胶囊中的姜黄素进行测定。着重研究了缓冲溶液浓度和酸碱度、检测电位、进样时间和高压对分离测定的影响。以微Pt电极为工作电极,电极电位为 1.0 V,以V(甲醇)∶V(乙醇)∶V(水)=5∶2∶3为非水介质,磷酸二氢钾和硼砂(pH 9.5)为缓冲体系,并用二阶样条小波进行滤波处理,姜黄素在1.0~120 mg/L范围内,峰高与其质量浓度呈良好的线性关系,线性回归方程:Y=20.2 146ρ,检出限为0.02 mg/L。     

毛细管电泳安培法检测酚类化合物

使用自行设计组装的毛细管电泳柱端安培检测系统 ,对四个酚类化合物进行了分离检测。研究了工作电极、缓冲液及其 p H值、检测电压和分离电压对分离检测的影响。在优化条件下 ,4个酚在 5× 1 0 -6～ 5× 1 0 -4 mol/L范围内峰高与浓度成良好的线性关系 ,检测下限为 8.5× 1 0 -7mol/L     

Determination of baicalin, chlorogenic acid and forsythin in Chinese medicinal preparation by capillary electrophoresis

Summary The determination of baicalin, chlorogenic acid and forsythin in a traditional Chinese medicinal preparation, Shuanghuanglian oral liquid, has been investigated by micellar electrokinetic capillary electrophoresis using borate buffer, SDS and acetonitrile as background electrolyte, 15 kV applied voltage and UV detection, the three active compounds were completely separated within 15 min. The effect of buffer pH, concentration of borate and SDS are discussed. Regression equations reveal linear relationships between the peak-area of each component and content. In addition, the levels of three active compounds in traditional Chinese medicinal preparation, Shuanghuanglian oral liquid, were easily determined with recoveries of 95.20–105.73%.     

毛细管电泳法测定复方芦丁片中的芦丁和维生素C

用毛细管电泳紫外检测法同时测定了复方芦丁片中芦丁和抗坏血酸的含量 ,研究了各种条件的影响 ,得到了优化的实验条件 ,在 30 mmol/L Na2 B4 O7-H3BO3( p H7.5 0 )缓冲溶液中 ,芦丁和维生素 C在 1 3min内得到了良好的分离 ,芦丁和维生素 C分别在 0 .5～ 0 .0 0 5 mg和 5 .0～ 0 .0 5 mg浓度范围内与电泳峰高呈现良好线性关系 ,检测下限分别为 0 .0 0 2 mg和 0 .0 1 mg,应用于实际样品的测定     

Separation and determination of rutin and quercetin in the flowers ofSophora japonica L. by capillary electrophoresis with electrochemical detection

Summary Capillary electrophoresis with amperometric detection has been evaluated for the simultaneous determination of rutin and quercetin. The cyclic voltammogram, hydrodynamic voltammogram, and the effects of pH, concentration of buffer and sodium dodecyl sulfate (SDS), and amount of organic modifier on the separation and the detection were studied. The optimized conditions were: detection potential 1.2V, separation at 12 kV, 5 s at 15 kV for sample injection, running electrolyte 20 mmol L⁻¹ borate buffer, pH 8.8, containing 40 mmol L⁻¹ SDS and 10% acetonitrile. The detection limit of the method was low, 0.001 and 0.0005 mg mL⁻¹, for rutin and quercetin, respectively; the linear ranges were wide −0.005–0.5 and 0.005–0.4 mg mL⁻¹, respectively. The variations in peak current and migration time for eight consecutive injections of a standard solution containing 0.1 mg mL⁻¹ of each compound were 4.78 and 3.63%, and 6.50 and 2.59% for rutin and quercetin, respectively. The levels of the two compounds in traditional Chinese herbal drugs were easily determined.     

毛细管区带电泳法测定复方芦丁片中芦丁和维生素C的含量

考察了缓冲溶液的pH、背景电解质浓度及分离电压对芦丁、维生素C及苯甲酸分离的影响，建立了以苯甲酸为内标，毛细管区带电泳法快速测定复方芦丁片中芦丁和维生素C含量的新方法。以3g/L硼砂－4g/L硼酸(pH8.18）为运行缓冲液，苯甲酸为内标，在分离电压为25kV，检测波长为254nm的电泳条件下，芦丁、维生素C和内标可在5min实现分离。芦丁的线性方程为：y=2．65x＋0．095（r＝0．9994），线性范围为0．025mg/mL－0．4mg/mL，维生素C的线性方程为：y＝3．1343x＋0．565（r＝0．9991），线性范围0．125mg/mL－1．0mg/mL。方法可用于复方芦丁片的质量控制。     

Separation and determination of flavonoids in three traditional chinese medicines by capillary electrophoresis with amperometric detection

Flavonoids are important active ingredients in many traditional Chinese medicines. In this paper, capillary electrophoresis with amperometric detection was employed to separate and detect eight flavonoids, rutin, quercetrin, quercetin, kaempferol, kaempferide, catechin, apigenin, and luteolin, in a home‐made capillary electrophoresis device. Under the separation voltage of 2000 V, the eight flavonoids could be completely separated within 33 min in 18 mM borax running buffer at pH 10.2. Good linear relationships were obtained for all analytes and the detection limits for flavonoids ranged from 0.46 to 0.85 μM. Then, the method was applied to separate and determine the flavonoids in three traditional Chinese medicines, hippophae rhamnoides, hypericum perforatum, and cacumen platycladi. Finally, rutin, kaempferol, quercetin, and quercetrin were discovered in these medicines and the concentrations ranged from 0.28 to 9.94 mg/g. The recoveries of flavonoids ranged from 84.7 to 113%, which showed the high reliability of this method.     

Determination of ionization constants of saccharides by capillary zone electrophoresis with amperometric detection

Summary A method based on a linear model enabling the efficient determination of the ionization constants (K _a) of saccharides by capillary zone electrophoresis with amperometric detection has been demonstrated. TheK _a values obtained from the plots of the reciprocal effective mobility against the inverse concentration of sodium hydroxide were in agreement with literature values.     

毛细管电泳柱端安培检测装置的研制

研制了一种新型的毛细管电泳柱端型安培检测装置。以直径为6μm的碳纤维微电极为工作电极,在自组装的ACS-2000毛细管电泳仪上,考察了用不同内径毛细管分离时分离电压对背景噪声的影响。利用该装置同时测定了3种苯二酚的异构体。     

Determination of enrofloxacin and its metabolite ciprofloxacin by high performance capillary electrophoresis with end-column amperometric detection

Enrofloxacin (ENR) and its metabolite ciprofloxacin (CIP) were determined by capillary zone electrophoresis (CZE) with end-column amperometric detection. The effect of several factors, such as pH and concentration of running buffer solution, separation voltage, injection time, and working potential, on CZE were investigated to establish the optimal conditions of separation and detection. Under a given set of conditions (pH 8.00 phosphate buffer solution (20 mmol/L); +0.95 V for the working potential; 18 kV for the separation voltage; sample injection at 18 kV for 10 s), the compounds investigated can be well separated and detected within 8 min. Excellent linearity was observed between peak currents and concentration of analytes in the range from 0.034 to 70.0 mg/kg for these two compounds. The detection limits (S/N= 3) for enrofloxacin and ciprofloxacin were 13.68 mg/kg and 14.35 mg/kg, respectively, which were about 7-fold lower than the maximum residue limits (MRLs) established by the European Union. A simple sample pretreatment method was developed and proved to be effective in obtaining good recoveries and short analysis time. The developed CE-AD method was simpler, faster, and less cost intensive than other reported methods, and allows the determination of ENR and its metabolite CIP in contaminated eel liver samples and other animal tissue samples at the required maximum residue limits.     

毛细管电泳柱上安培检测装置的研制

介绍了一种新的毛细管电泳柱上安培检测装置。以碳纤维微电极为工作电极,在自组装的ACS－2000毛细管电泳仪上,测定了三种苯二酚的异构体：邻苯二酚、对苯二酚、间苯二酚,在20min内达到了基线分离。     

高速毛细管电泳安培法检测甲巯咪唑及其制剂

采用高速毛细管电泳安培法对甲巯咪唑(TMZ)及其制剂的测定进行了研究; 通过优化检测电位、毛细管长度和内径、分离电压、缓冲溶液等实验参数, TMZ在60 s内可以得到较好的分离, 线性范围在2.00×10-3～2.80×10-5 mol/L, 检出限为3.50×10-6 mol/L; 峰面积和迁移时间的相对标准偏差分别为2.7%、 1.2% (n＝8); 该法可用于制剂中TMZ的检测.     

Fast determination of sugars in Coke and Diet Coke by miniaturized capillary electrophoresis with amperometric detection

The fast separation capability of a novel miniaturized capillary electrophoresis with amperometric detection (CE-AD) system was demonstrated by determining sugar contents in Coke and diet Coke with an estimated separation efficiency of 60,000 TP/m. Factors influencing the separation and detection processes were examined and optimized. The end-capillary 300 microm Cu wire amperometric detector offers favorable signal-to-noise characteristics at a relatively low potential (+0.50 V vs. Ag/AgCl) for detecting sugars. Three sugars (sucrose, glucose, and fructose) have been separated within 330 s in a 8.5 cm length capillary at a separation voltage of 1000 V using a 50 mM NaOH running buffer (pH 12.7). Highly linear response is obtained for the above compounds over the range of 5.0 to 2.0 x 10(2) microg/mL with low detection limit, down to 0.8 microg/mL for glucose (S/N = 3). The injection-to-injection repeatability for analytes in peak current (RSD < 3.6%) and for migration times (RSD < 1.4%) was excellent. The new miniaturized CE-AD system should find a wide range of analytical applications involving assays of carbohydrates as an alternative to conventional CE and micro-CE.     

Simultaneous determination of electroactive and non-electroactive food preservatives by novel capillary electrophoresis with amperometric detection

A novel capillary electrophoresis and amperometric detection method was achieved by adding an electroactive additive (3,4-dihydroxybenzylamine, 3,4-DHBA) to the running buffer, so that both electroactive and non-electroactive food preservatives were simultaneously determined. Under the selected optimum conditions, four electroactive preservatives (methylparaben, ethylparaben, propylparaben and butylparaben) and two non-electroactive preservatives (potassium sorbate and sodium lactate) were well separated and sensitively detected with detection limits (S/N = 3) ranging from 1.06 × 10⁻⁸ to 2.73 × 10⁻⁶ g mL⁻¹. This method has been successfully employed for the determination of both electroactive and non-electroactive preservatives in several food commodities.     

Determination of four kinds of carbamate pesticides by capillary zone electrophoresis with amperometric detection at a polyamide-modified carbon paste electrode

In this paper, a polyamide-modified carbon paste electrode in capillary zone electrophoresis with amperometric detection (CZE-AD) was firstly applied to the determination of four carbamate pesticides: fenobucarb, isoprocarb, metolcarb and carbaryl. The four carbamates were hydrolyzed in alkalescent aqueous solutions, resulting in the formation of 2-sec-butylphenol, 2-isopropylphenol, m-cresol and α-naphthol, which could be determined by amperometry after capillary electrophoretic separation. Under the selected optimum conditions, the four analytes could be perfectly separated within 23 min. The linear ranges of 2-sec-butylphenol, 2-isopropylphenol and m-cresol were from 1.0 × 10⁻⁷ to 2.0 × 10⁻⁵ mol L⁻¹ and that of α-naphthol was from 2.0 × 10⁻⁷ to 2.0 × 10⁻⁵ mol L⁻¹ and their detection limits were 3.0 × 10⁻⁸, 3.0 × 10⁻⁸, 3.0 × 10⁻⁸ and 6.0 × 10⁻⁸ mol L⁻¹, respectively (S/N = 3). Fenobucarb, isoprocarb, metolcarb and carbaryl can be indirectly determined by this CZE-AD method with recovery of 105, 104, 110 and 98% and R.S.D. of 4, 3, 4 and 3%, respectively. Above results demonstrated that this method was of high sensitivity, good repeatability and could be used in the rapid determination of the pesticide residues.     

氯霉素的高效毛细管电泳分离-电导检测

在熔融石英毛细管(50μmi.d×50cm)中,以6mmol/LH3BO3 2mmol/L硼砂 体积分数0.02%TEPA(四乙烯五胺)为电泳运行介质,分离电压-15.0kV,采用毛细管电泳-电导检测法在4min内实现了氯霉素的分离检测。讨论了电渗流抑制剂的浓度、缓冲体系的组成和浓度等因素对检测结果的影响。线性检测范围为1~120mg/L,检出限为0.3mg/L。对市售氯霉素滴眼液和注射液中的氯霉素进行分析,加标回收率为93.8%~106.8%。     

Determination of dioxopromethazine hydrochloride by capillary electrophoresis with electrochemiluminescence detection

The paper presents a rapid method for the determination of dioxopromethazine hydrochloride (DPZ), an antihistamine drug, by the capillary electrophoresis with electrochemiluminescene detection (CE–ECL) using tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺) reagent. This CE–ECL detection method has high sensitivity, good selectivity and reproducibility for DPZ analysis. Under the optimized conditions: separation capillary, 38 cm length (25 μm i.d.); sample injection, 10 s at 8 kV; separation voltage, 12.5 kV; running buffer, 20 mmol L⁻¹ sodium phosphate of pH 6.0; detection potential, 1.15 V; 50 mmol L⁻¹ of phosphate buffer (pH 7.14) containing 5 mmol L⁻¹ of Ru(bpy)₃²⁺ in ECL detection cell, the detection limit of DPZ was 0.05 μmol L⁻¹ (S/N = 3). The linear range extended from 5 to 100 μmol L⁻¹. The linear curve obtained was Y = 181.62 + 9.28X with a correlation coefficient of 0.9970. The relative standard deviations of the ECL intensity and the migration time for six continuous injections of 5 μmol L⁻¹ DPZ were 3.7% and 0.92%, respectively. The CE–ECL method was applied to analyze DPZ in real samples including tablets, rat serum and human urine, and satisfactory results were obtained without interference from samples matrix. The CE–ECL technique was proved to be a potential method for the detection of DPZ in clinic analysis.     

Fabrication and performance of a three-dimensionally adjustable device for the amperometric detection of microchip capillary electrophoresis

A microchip CE-amperometric detection (AD) system has been fabricated by integrating a two-dimensionally adjustable CE microchip and an AD cell containing a one-dimensionally adjustable disk detection electrode in a Plexiglas holder. It facilitates the precise 3-D alignment between the channel outlet and the detection electrode without a complicated 3-D manipulator. The performance of this unique system was demonstrated by separating five aromatic amines (1,4-phenyldiamine, aniline, 2-methylaniline, 4-chloroaniline, and 1-naphthylamine) of environmental concern. Factors influencing their separation and detection processes were examined and optimized. The five analytes have been well separated within 140 s in a 74 cm long separation channel at a separation voltage of +2500 V using a 10 mM phosphate buffer (pH 3.5). Highly linear response is obtained for the five analytes over the range 20-200 microM with the detection limits ranging from 0.46 to 1.44 microM, respectively. The present system demonstrated long-term stability and reproducibility with RSDs of less than 5% for the peak current (n = 9). The new approach for the microchannel-electrode alignment should find a wide range of applications in CE, flowing injection analysis, and other microfluidic analysis systems.     

毛细管电泳电化学检测法测定烟草中的多元酚

采用毛细管电泳电化学检测法同时测定了烟草中的多元酚,即芦丁、绿原酸,槲皮素和咖啡酸。考察了工作电极的氧化电位、运行缓冲溶液浓度和pH值,分离电压和进样时间对分离和检测的影响。在优化条件下,以300μm直径的碳圆盘电极为工作电极,检测电位为+0.9 V(vs.SCE),在50 mmol/L硼酸盐(pH 8.4)的运行缓冲液中,被测物浓度与峰电流在三个数量级范围内呈良好线性,检出限为2×10-7或5×10-7g/mL。方法有着良好的重现性,被测组分的迁移时间和峰高的相对标准偏差(RSDs)小于4%(n=7)。单次测定可在16 min内完成,已用于实际样品多元酚的测定,样品处理简单,无须预富集。