毛细管电泳-电化学检测法测定葡萄和葡萄酒中的白藜芦醇

采用毛细管电泳-电化学检测法测定了葡萄和葡萄酒中的白藜芦醇含量,实验发现白藜芦醇在红葡萄酒中的含量明显高于其在白葡萄酒中的含量,并验证原因为葡萄皮中白藜芦醇的含量显著高于葡萄肉中白藜芦醇的含量。考察了工作电极的工作电位、分离电压和进样时间对检测的影响。在优化条件下,以300μm直径的碳圆盘电极为工作电极,工作电位为+0.85V(vs.SCE),在100mmol/L硼酸盐(pH=9.2)的运行缓冲液中,被测物浓度与峰电流在3个数量级范围内呈良好线性,检出限为1×10-7g/mL。该法简单可靠,已成功地应用于实际样品中白藜芦醇含量的测定;样品处理简单,无须预富集,检测结果令人满意。     

毛细管电泳-电化学检测法测定蜘蛛香中多元酚类化合物

采用毛细管电泳 电化学检测法(CE ED)同时测定了蜘蛛香根中香叶木素、山奈酚、芹菜素、绿原酸 和咖啡酸等5种主要生物活性成分的含量,考察了运行缓冲液酸度、浓度、分离电压、氧化电位和进样时间等 实验参数对分离、检测的影响。在最佳实验条件下,以直径300μm的碳圆盘电极为工作电极,检测电位为+ 950mV(vs.SCE),在50mmol/L的硼砂缓冲溶液(pH9.23)中,上述各组分在23min内能完全分离。5种组 分在两个数量级的范围内呈良好线性关系,检测下限(S/N=3)达1.7×10-4～1.8×10-5g/mL。该法已成功 地应用于蜘蛛香根中活性成分的分离检测,结果令人满意。     

毛细管电泳-电化学检测法测定中药杠版归中的活性成分

采用毛细管电泳-电化学检测法（CE-ED）同时分离测定了中药杠板归中的阿魏酸、香草酸、槲皮素、咖啡酸、原儿茶酸等主要生物活性成分的含量。考察了工作电极电位、运行缓冲液的pH值和浓度、分离电压和进样时间等实验参数对实验结果的影响。在优化的实验条件下,以直径300 μm的碳圆盘电极为工作电极,检测电位为＋0.95V(vs. SCE),在10mmol/L磷酸盐（pH 9.2）的运行缓冲溶液中,五个分析物能够在17min内实现很好的基线分离,被测物浓度与峰电流在3个数量级呈良好的线性,检测限（S/N＝3）范围从7.1×10-8 到 9.3×10-8g mL-1。该方法已应用于实际样品的分析,样品处理简单,获得了令人满意的结果。     

毛细管电泳-电化学检测法测定血浆中水溶性小分子抗氧化剂

应用毛细管电泳电化学检测方法,以金属铜电极为检测电极,研究了同时测定人血浆中水溶性小分子抗氧化剂谷胱甘肽(GSH)、尿酸(UA)、色氨酸(Try)和半胱氨酸(Cys)的最佳条件。在最佳实验条件下,各组分的线性范围在1.0×10-6～5.0×10-4mol/L内;检出限在10-6mol/L数量级。该法具有分析速度快、灵敏度高等优点,对血浆样品的测定取得了满意的结果。     

毛细管电泳-电化学检测法测定淮山中8种必需氨基酸含量

将8种人体内必需氨基酸(苏氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、苯丙氨酸、赖氨酸、色氨酸)与邻苯二甲醛(OPA)发生衍生化反应,再采用毛细管电泳-电化学检测(CE-ED)方法对其含量进行测定。考察了衍生化时间、检测电位、运行缓冲液浓度和p H值、分离电压及进样时间等的影响。在优化条件下,8种氨基酸在12 min内实现了分离,线性范围为0.1~1 500μg/L;检出限为0.01~0.05μg/L,峰高的相对标准偏差(RSD)为1.3%~1.8%,迁移时间的RSD为0.6%~1.0%。该方法已用于淮山样品中8种必需氨基酸的测定,加标回收率为96.8%~102.0%,RSD均不大于2.4%。     

毛细管电泳-电化学检测法测定淮山中5种活性成分

建立了毛细管电泳-电化学检测法同时测定淮山中活性成分甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖的分析方法。考察了检测电位,运行缓冲溶液的浓度及pH值,分离电压及进样时间等的影响。在优化条件下,13min内可实现甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖的基线分离。甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖的浓度与峰电流均在3个数量级范围呈良好的线性关系,其检出限分别为0.45、0.56、0.35、0.78、0.65μmol/L。峰电流的相对标准偏差(RSD)分别为2.03%、1.23%、1.25%、1.27%和1.21%。该方法已用于淮山样品中甘露糖、鼠李糖、葡萄糖、半乳糖和阿拉伯糖的测定,加标回收率在97.8%~100.8%之间,相对标准偏差(RSD)≤2.3%。     

毛细管电泳-电化学检测法测定黄芪及其制剂中的活性成分

采用毛细管电泳-电化学检测法(CE-ED)对中药黄芪的主要活性成分芦丁、阿魏酸、香草酸、绿原酸、槲皮素和咖啡酸进行了分离和测定。分别考察了工作电极电位、运行缓冲液的pH值和浓度、分离电压和进样时间等实验参数对实验结果的影响。在优化的实验条件下,以直径300 μm的碳圆盘电极为工作电极,检测电位为+0.95 V(相对于饱和甘汞电极),在10 mmol/L硼酸盐(pH 8.2)的运行缓冲溶液中,上述6种活性成分能在17 min内实现很好的基线分离,被测物浓度与峰电流在3个数量级范围呈良好的线性关系,检出限(S/N=3)范围为78～110 μg/L。在不同的加标水平下,6种活性成分的平均回收率为96.0%～103.0%,相对标准偏差为1.9%～3.6%(n=3)。该方法样品处理简单,无需预富集,已应用于实际样品的分析,并获得了令人满意的结果。     

毛细管电泳-电化学检测法分析竹叶及竹叶茶中的活性成分

用毛细管电泳-电化学检测(CE-ED)法同时测定了五种不同竹叶和竹叶茶中的香兰素、顺式阿魏酸、对羟基苯甲醛、对香豆酸、对羟基苯甲酸、香草酸和咖啡酸的含量,考察了实验参数对分离、检测的影响,得到了最佳实验条件.以直径300 μm的碳圆盘电极为检测电极,电极电位为+0.95 V (vs.SCE),在60 mmol/L硼酸盐缓冲溶液(pH=8.7)中,上述七种组分在22 min内实现较好的分离.七组分的浓度和峰电流在2～3个数量级范围内呈良好线性关系,检出限范围为1.9×10-8～9.8×10-8 g/mL.该法用于实际样品的分析,结果令人满意.     

毛细管电泳-电化学检测法用于中药石韦中绿原酸和槲皮素的同时测定

建立了毛细管电泳同时分离测定中药石韦中绿原酸、槲皮素含量的分析方法．采用柱端喷壁式三电极系统的电化学检测方式,工作电极为0．5mm碳圆盘电极;参比电极为．Ag／AgCl;辅助电极为铂丝电极．以70cm(o．d360μm．i.d25μm)的熔融石英毛细管为分离通道,在最佳电泳介质(pH=7．0,10．0mmol／L磷酸盐缓冲溶液)中,当分离电压为21kV时,两待测物质在8min内完全分离．在最佳分离、检测条件下,响应电流与浓度之间的线性关系良好,绿原酸、槲皮素的线性方程分别为：y=0．268x 1．088、y=0．312x 0．822,相关系数大于0．999,绿原酸、槲皮素检测限分别达0．075μg／mL和0．020μg／L该方法具有良好的重现性,峰电流的RSD小于3．5％．已成功的用于实际中药石韦和模拟血样中绿原酸、槲皮素的含量测定,结果令人满意．     

毛细管电泳-电化学检测法用于生物碱电离常数线性模型的研究

依据毛细管区带电泳的特性,推导出在不同pH条件下,有效淌度的倒数(1/μep)与缓冲溶液中氢离子浓度([H^ ])成线性关系,进而建立了用毛细管电泳-电化学检测法测定四种生物碱：苯异丙胺、苯丙醇胺、麻黄碱和甲基麻黄碱电离常数的线性模型和测定方法,测得的pKa值,与紫外分光光度法测定值及文献值比较,结果令人满意．可望在药物离解常数测定的应用中得到推广．     

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。     

Separation of six purine bases by capillary electrophoresis with electrochemical detection

Capillary zone electrophoresis with electrochemical detection (ED) has been employed for the separation and determination of adenine (A), guanine (G), theophylline (Thp), hypoxanthine (HX), xanthine (Xan) and uric acid (UA). Effects of several important factors such as the acidity and concentration of running buffer, separation voltage, injection time and detection potential were investigated to acquire the optimum conditions. The detection electrode was a 300 μm carbon disc electrode at a working potential of +0.95 V (versus saturated calomel electrode (SCE)). The six purine bases can be well separated within 14 min in a 40 cm length fused-silica capillary at a separation voltage of 10 kV in a 100 mmol/l borate buffer (BB, pH 10.0). The current response was linear over about three orders of magnitude with detection limits (S/N=3) ranging from 0.157×10⁻⁶ to 0.767×10⁻⁶ mol/l for all compounds. The proposed method was successfully applied to determine Thp in tea and aminophylline tablets, UA in human urine, and two purine bases in DNA.     

Determination of monoamine transmitters and tyrosine in biological samples by capillary electrophoresis with electrochemical detection

Summary Capillary electrophoresis (CE) has been employed for the separation of monoamine transmitters (MAs) and tyrosine (Tyr), combined with electrochemical detection (ED) at a carbon disc electrode. The effects of several factors such as the acidity and concentration of running buffer, the separation voltage, the potential applied to the working electrode and the injection time were investigated to find the optimum conditions. Detection limits (S/N=3) ranged from 48.8 to 315.4 nmol·L⁻¹, and the response was linear over 3 order of magnitude for MAs and Tyr. The proposed method was successfully applied to determine MAs and Tyr in the cerebral cortex, thalamus and spinal cord of rats with satisfactory assay results.     

毛细管电泳电化学检测法同时测定三种氨基酸的电离常数

利用自制微圆盘铜电极,建立了一种毛细管电泳电化学检测同时测定色氨酸、丝氨酸和半胱氨酸pKα值的新方法。在不同pH条件下测定各氨基酸的有效淌度（μeff）,利用Origin软件对μeff-[H^＋]按理论关系式进行非线性拟合,得到其pKα值。该方法简便、快速,测定值与文献值符合良好。     

Assay of amino acids in individual human lymphocytes by capillary zone electrophoresis with electrochemical detection

Amino acids in individual human lymphocytes were determined by capillary zone electrophoresis with electrochemical detection (ED) at a carbon fiber bundle electrode after on-column derivatization with naphthalene-2,3-dicarboxaldehyde (NDA) and CN⁻. In order to inject cells easily, a cell injector was designed. In this method, a single human lymphocyte and then the lysing/derivatizing buffer were electrokinetically injected into the front end of the separation capillary as a chamber to lyse the lymphocyte and derivatize amino acids in the cell. Four amino acids (serine (Ser), alanine (Ala), taurine (Tau), and glycine (Gly)) in single human lymphocytes have been identified. Quantitation has been accomplished through the use of calibration curves.     

Determination of hypaphorine and oligomeric stilbenes in the root of Caragana sinica by capillary electrophoresis with electrochemical detection

Capillary electrophoresis with electrochemical detection (CE-ED) was employed for the determination of hypaphorine (an alkaloid) and four oligomeric stilbenes (including pallidol, kobophenol A, miyabenol C and (+)--viniferin) in Radix seu Cortex Caraganae Sinicae, the root of Caragana sinica (Buc'hoz) Rehd. The effects of several important factors were investigated to find optimum conditions. The working electrode was a 300 μm diameter carbon disc electrode positioned opposite the outlet of capillary. The five analytes could be well separated within 12 min in a 40 cm length capillary at the separation voltage of 12 kV in a 100 mmol l⁻¹ borate buffer (pH 10.0). The response was linear over about three orders of magnitude for all investigated compounds with detection limits (S/N=3) ranging from 0.0385 to 0.111 mg l⁻¹. This proposed method has also been successfully applied to analyze the root of other Caragana plants.     

Determination of uric acid in human saliva by capillary electrophoresis with electrochemical detection: potential application in fast diagnosis of gout

The clinical manifestations of gout result from the formation and deposition of uric acid (UA) crystals. The monitoring of UA level in less invasive biological samples such as saliva is suggested for diagnosis and therapy of gout, hyperuricemia and the Lesch–Nyhan syndrome. In order to investigate the correlation between trace amounts of UA in human saliva and urine and explore the potential application in fast diagnosis of gout, capillary electrophoresis with electrochemical detection (CE–ED) was applied for the determination of UA in human saliva and urine in this work. Under the optimum conditions, UA and three coexisting analytes could be well separated within 14 min at the separation voltage of 14 kV in 80 mmol L^–1 borax running buffer (pH 7.8). A good linear relationship was established between peak current and concentration of analytes over two orders of magnitude with detection limits (S/N=3) ranging from 1.09×10^–7 to 5.0×10^–7 mol L^–1 for all analytes. This proposed method has been successfully applied for study of the correlation between the UA content of human saliva and urine, providing an alternative and convenient method for rapid diagnosis of gout.     

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。     

Study of uptake kinetics of vincristine for human erythrocytes by capillary zone electrophoresis with electrochemical detection

Capillary zone electrophoresis (CZE) was employed for the determination of vincristine using electrochemical detection with a carbon fiber microdisk bundle electrode at a constant potential of 1.0 V versus saturated calomel electrode (SCE). The optimum conditions of separation and detection are 1.7×10⁻² Na₂HPO₄− 3.2×10⁻³ mol/l NaH₂PO₄ (pH 7.5) for the buffer solution, 20 kV for the separation voltage. The limit of detection is 5.0×10⁻⁷ mol/l or 2.2 fmol (S/N=3) for the injection voltage of 5 kV and the injection time of 10 s. The recovery of the method is between 95 and 101% for the vincristine taken by human erythrocytes. The method was applied to investigate uptake and accumulation behavior of vincristine for human erythrocytes. The advantages of the method are the small sample volume of CZE and the high selectivity and sensitivity of electrochemical detection.     

Determination of barbituric acid and 2-thiobarbituric acid with end-column electrochemical detection by capillary electrophoresis

Capillary electrophoresis (CE) with end-column electrochemical detection (EC) of barbituric acid (BA) and 2-thiobarbituric acid (TA) has been described. Under optimum condition, BA and TA were separated satisfactorily, and a response of high sensitivity and stability was obtained at a detection potential of 1.25 V versus Ag/AgCl. Optimized end-column detection provides detection limit as low as 0.5 and 0.1 μM for BA and TA, respectively. The calibration graph was linear over three orders of magnitude. The relative standard deviations (n=10) of peak currents and migration times obtained for both BA and TA were 3.4, 3.7, and 1.7, 1.2%, respectively. The proposed method has been applied to analyze water sample with satisfactory results.