首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 203 毫秒
1.
毛细管电泳电化学检测法测定烟草中的多元酚   总被引:5,自引:1,他引:5  
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。  相似文献   

2.
建立了毛细管区带电泳 -电化学检测法 (CE -ED)测定芦丁和5_羟色胺含量的方法 ,研究了电极电位、运行缓冲液的酸度和浓度、电泳电压及进样时间等因素对分离检测的影响,确定了最佳测定条件 ;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50mmol/L硼酸盐缓冲液(pH8.5)中,上述2组分在12min内完全分离 ,被分析物的电流响应与浓度在约3个数量级范围内呈良好线性关系,检出限分别为3×10-7 mol/L和8×10-8 mol/L ,7次测定含5.0×10-4 mol/L的芦丁和5_羟色胺的标准溶液,峰高的相对标准偏差分别为2.5 %和3.8 % ;该法成功地用于中药沙棘黄酮口服液中芦丁和5_羟色胺的测定  相似文献   

3.
首次采用毛细管电泳—电化学检测法(CE-ED)同时测定山楂中的6种活性成分:表儿茶素,山奈酚,氯原酸,4-羟基苯甲酸,槲皮素和原儿茶酸的含量。考察了缓冲液酸度和浓度、检测电位、分离电压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,工作电极为直径300µm的碳圆盘电极,检测电位为+0.95V(vs. SCE), 缓冲液为60mmol/L 硼砂—硼酸溶液(pH=8.7), 分离电压16kV,上述六组分在21 min 内即可实现分离。六种组分在三个数量级的范围内呈良好线性关系,检测下限(S/N=3)范围为3.0×10-8g mL-1 至2.0×10-7g mL-1该方法已成功地应用于实际样品分析,结果令人满意。  相似文献   

4.
采用毛细管电泳电化学检测法测定了胡黄连中香草酸和阿魏酸的含量 ;研究了电极电位、运行缓冲液的浓度和酸度、电泳电压及进样时间等对电泳的影响 ,得到了最优化的测定条件 ;以直径为300μm的碳圆盘电极为检测电极 ,工作电极电位为0.8V(vs.SCE) ,在50mmol/L硼砂(pH8.4)运行缓冲液中 ,上述两组分在8min内完全分离 ;香草酸和阿魏酸线性范围分别为5×10-4~1×10-6 mol/L和1×10-3~1×10-6 mol/L ,检出限分别为4.2×10 -7和3.0×10 -7mol/L ;7次平行进样的相对标准偏差(RSD)为2.2 %和2.8 % ,回收率(n=3)分别为99%和103 % ,该法灵敏可靠 ,结果令人满意。  相似文献   

5.
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。  相似文献   

6.
楚清脆  傅亮  林淼  叶建农 《分析化学》2005,33(11):1611-1614
采用毛细管区带电泳-安培检测法(CZE-AD)同时分离测定了中药地骨皮中刺槐素、莨菪亭、山奈酚、对香豆酸、香草酸、木犀草素和槲皮素等多种生物活性成分,考察了运行液酸度和浓度、分离电压、氧化电位和进样时间等实验参数对分离、检测体系的影响。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950 mV(vs.SCE),在80 mmol/L的硼砂缓冲溶液(pH 9.0)中,7组分在24 m in可实现基线分离。7组分峰电流与其浓度在1.0×10-3~1.0×10-1范围内呈良好线性,检出限(S/N=3)达3.5×10-5~6.0×10-5g/L。该方法成功地应用于中药地骨皮中生物活性成分的含量检测。  相似文献   

7.
基于尼古丁对胆碱氧化酶(CHOD)的抑制作用,将胆碱氧化酶电极用于微量尼古丁的测定。酶电极制作中,先在铂电极表面修饰一层壳聚糖膜,再用戊二醛交联CHOD。采用这种酶固定化方法,电极在4. 0×10-6 ~ 3×10-3 mol/L胆碱的浓度范围呈线性关系。探讨了工作电位、pH、底物浓度等实验条件对酶电极性能及抑制过程中响应电流的影响,测定了电极的重现性、干扰及使用寿命。电极检测尼古丁的线性范围为1. 5×10-5 ~3×10-3 mol/L;检出限为1. 25×10-5 mol/L。将电极用于实际样品烟草中尼古丁回收率的测定,结果良好。  相似文献   

8.
毛细管电泳-电化学检测法测定饲料中的磺胺类药物   总被引:1,自引:0,他引:1  
采用毛细管电泳-电化学检测法(CE-ED),对饲料中的6种磺胺类药物磺胺脒、磺胺二甲嘧啶、磺胺甲嘧啶、磺胺二甲氧嘧啶、磺胺嘧啶、磺胺甲恶唑进行了分离和测定。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300μm的碳圆盘电极为工作电极,检测电位为0.95 V(vs.SCE),在30 mmol/L硼砂-KH2PO4(pH7.6)的运行缓冲溶液中,6个分析物能够在16 min内实现很好的基线分离,被测物浓度与峰电流在3个数量级呈良好的线性,检出限(S/N=3)范围0.08~0.20μg/mL。该方法已应用于实际样品的分析。  相似文献   

9.
毛细管区带电泳 -电化学检测法同时测定散利痛片中有效成分扑热息痛和异丙基安替比林的含量 ;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 ,得到了最优化的测定条件 ;以直径为300μm的碳圆盘电极为检测电极 ,工作电极电位为1.0V(vsSCE) ,在50mmol/L硼砂 -NaOH(pH9.35)运行缓冲液中 ,上述两组分在8min内完全分离 ;扑热息痛和异丙基安替比林线性范围分别为2×10-3~5×10 -6mol/L和2×10 -3~2×10 -6mol/L,检出限分别为5×10 -6mol/L和2×10 -6mol/L ;7次平行进样的相对标准偏差(RSD)为3.5%和1.8 % ,加标回收率(n=3)分别为101 %和98% ,该法灵敏可靠 ,结果令人满意。  相似文献   

10.
采用毛细管电泳电化学检测法同时测定了枳实和枳壳中的辛弗林和3种黄酮即橙皮甙、柚皮素和柚皮甙的含量。考察了工作电极的氧化电位、分离电压和进样时间,运行缓冲的浓度和pH值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检测电极,检测电位为 0.85 V(vs.SCE),在80 mmol/L硼酸盐(pH 8.45)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(S/N=3)在1×10-4~5×10-4g/L之间,该法简单、可靠、快速,单次测定可在20 m in内完成,已经成功应用于实际样品枳实和枳壳中4组分的测定,样品处理简单,无须预富集,检测结果令人满意。  相似文献   

11.
A method based on capillary electrophoresis with electrochemical detection has been developed for the separa-tion and determination of epicatechin,kaempferol,chlorogenic acid,4-hydroxybenzoic acid,quercetin and proto-catechuic acid in hawthorn for the first time.The effects of working electrode potential,pH and concentration ofrunning buffer,separation voltage and injection time on CE-ED were investigated.Under the optimum conditions,the analytes could be separated in a 60 mmol·L~(-1) borate buffer(pH 8.7)within 21 min.A 300 μm diameter carbondisk electrode has a good response at 0.95 V(vs.SCE)for all analytes.The response was linear over three ordersof magnitude with detection limits(S/N=3)ranging from 3×10~(-8) to 2×10~(-7) g·mL~(-1) for the analytes.The methodhas been successfully applied to the analysis of real sample,with satisfactory results.  相似文献   

12.
《Analytical letters》2012,45(15):2861-2875
Abstract

A method based on capillary electrophoresis with electrochemical detection (CE‐ED) has been developed for the first time for the separation and determination of isovanillic acid, vanillic acid, quercetin, rosmarinic acid, caffeic acid, and protocatechuic acid in Origanum vulgare L. and its medicinal preparations. The effects of working electrode potential, pH level, concentration of running buffer, separation voltage, and injection time on CE‐ED were investigated. Under the optimum conditions, the analytes could be separated in a 50 mmol L?1 borate buffer (pH 8.7) within 21 min. A 300‐µm diameter carbon disk electrode has a good response at +0.95 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N=3) ranging from 4×10?8 g mL?1 to 2×10?7 g mL?1 for the analytes. The method has been successfully applied to the analysis of real sample, with satisfactory results.  相似文献   

13.
A micellar electrokinetic capillary chromatography method with electrochemical detection (MECC‐ED) has been developed for the simultaneous determination of eight phenolic additives, including propyl gallate (PG), tert‐butylhydroquinone (TBHQ), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in cosmetic products. Method development involved optimization of the working electrode, the pH value of running buffer, the concentration of sodium dodecyl sulfate (SDS), the separation voltage, and the sample injection time. Under the optimum conditions, all analytes can be well separated within 26 min at the separation voltage of 18 kV in a 9 mmol·L?1 sodium dodecyl sulfate (SDS) ?60 mmol·L?1 borate running buffer (pH 8.0). A 300 μm diameter carbon disk electrode generated good response at +0.90 V (vs. SCE) for all analytes. Linearity of the present method was over three orders of magnitude of analyte concentration with detection limits (S/N=3) ranging from 1.1×10?7 to 1.2×10?6 g·mL?1 for all analytes. This proposed method has been successfully applied to the simultaneous determination of the above additives in commercial cosmetics, and the assay results were satisfactory.  相似文献   

14.
采用毛细管电泳/安培检测法(CE/AD)同时分离测定了绿茶中的芦丁、没食子酸、槲皮素、绿原酸等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。在最优化条件下, 以300 μm碳圆盘电极为检测电极, 检测电位为+ 950 mV (vs. SCE) , 60 mmol/L硼酸盐运行缓冲液(pH 8.7)中, 上述各组分在20 min内可实现基线分离。各组分浓度与峰电流在3个数量级范围内呈良好线性, 检出限(S/N=3)在1.0×10-7到1.0×10-4g.mL-1范围,四种标样7次平行进样的相对标准偏差(RSD)小于3.0 %。该方法已成功地应用于绿茶中生物活性成分的测定, 结果令人满意。  相似文献   

15.
A simple, accurate method based on capillary electrophoresis with electrochemical detection (CE–ED) has been developed to determine loureirin A, loureirin B and dracorhodin for differentiation of Resina Draconis from Sanguis Draconis. The effects of some important factors such as acidity and concentration of running buffer, separation voltage, injection time, and applied potential on the CE–ED working electrode were investigated. Under the optimum conditions, the three analytes could be well separated within 30 min in a 75 cm capillary at a separation voltage of 14 kV in a 80 mmol L?1 borate buffer (pH 9.24). The working electrode was a 300-μm-diameter carbon disc electrode positioned opposite the outlet of the capillary in a wall-jet configuration and was set at a potential of 0.90 V (vs. SCE). Excellent linearity was established over two orders of magnitude with detection limits (S/N = 3) ranging from 3 × 10?7 g mL?1 to 1 × 10?6 g mL?1 for all three analytes. The relative standard deviations of peak current and migration times of loureirin A, loureirin B and dracorhodin were 2.1, 1.7, 4.4 and 2.9, 2.8, 3.3% (n = 5), respectively. The recoveries of three constituents ranged from 98.8 to 101.8%. The methodology has been successfully applied to analyze and differentiate the actual samples with satisfactory assay results.  相似文献   

16.
A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of epicatechin, isovanillic acid, vanillic acid and myricetin in Dioscorea bulbifera L. and its medicinal preparations. The effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time were investigated. Under optimum conditions, the analytes could be separated in a 40 mmol L?1 borate buffer (pH 8.7) within 15 min. A 300 μm diameter carbon disk electrode has a good response at + 0.95 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N = 3) ranging from 3.0 × 10?8 g mL?1 to 1.0 × 10?7 g mL?1. The method has been successfully applied to the analysis of real samples.  相似文献   

17.
《Analytical letters》2012,45(10):1783-1795
The behavior of seven hydroxy anthraquinone derivatives was studied by capillary zone electrophoresis and micellar electrokinetic chromatography. The effects of buffer pH (6.5–10.8) and sodium dodecyl sulfate concentration (10–20 mmol L?1) on the effective mobilities of the analytes and their separation were tested. A comparison of the two optimized separation systems showed that micellar electrokinetic chromatography was superior as it permits separation of all the seven analytes within 15 min, using 15 mmol L?1 sodium dodecyl sulfate in 10 mmol L?1 tetraborate buffer, pH 8.5, at a voltage of 20 kV. The calibration curves were linear in the concentration range from 5.0 · 10?7 to 5.0 · 10?4 mol L?1 for most of the analytes, at a detection wavelength of 254 nm. LOD and LOQ values of the analytes were in the ranges of 2.10 · 10?7–1.28 · 10?6 mol L?1and 6.99 · 10?7–4.25 · 10?6 mol L?1, respectively. The proposed separation conditions were applied to determination of 1,2-dihydroxy anthraquinone (alizarin) and 1,2,4-trihydroxy anthraquinone (purpurin) in Rubia tinctorum aglycone and of the recently described 1-acetyl-2,4,5,7-tetrahydroxy-9,10-anthraquinone and 1-acetyl-2,4,5,7,8-pentahydroxy-9,10-anthraquinone in the mycelium of fungi Geosmithia lavendula.  相似文献   

18.
Y. Y. Peng  F. H. Liu  J. N. Ye 《Chromatographia》2004,60(9-10):597-602
A method based on capillary electrophoresis with electrochemical detection (CE-ED) has been developed for the determination of bioactive flavonoids in the traditional Chinese herbal medicine, Rhododendron dauricum L. The effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time on CE-ED were investigated. Under the optimum conditions, the analytes could be separated in a 70 mmol L?1 borate buffer (pH=9.2) within 20 min. A 300 μm diameter carbon disk electrode has a good response at + 0.90 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N = 3) ranging from 2 × 10?8 g mL?1 to 2 × 10?7 g m?1 for the analytes. The method has been successfully applied for the analysis of real sample, with satisfactory results.  相似文献   

19.
《Electroanalysis》2005,17(18):1675-1680
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.  相似文献   

20.
《Electroanalysis》2003,15(10):898-902
A method based on capillary electrophoresis (CE) with electrochemical detection (ED) was developed for the determination of taurine in Lycium Barbarum L., LIPOVIYAN beverage and milk powder. The effects of some important factors such as the acidity of the running buffer, separation voltage, injection time, and applied potential to working electrode were investigated. Operated in a wall‐jet configuration, a 300 μm diameter carbon‐disk electrode was used as the working electrode, which exhibits good responses at +1.05 V (vs. SCE) for taurine. Excellent linearity was obtained in the concentration range from 5.0×10?4 mol/L to 5.0×10?6 mol/L. The detection limit (S/N=3) was 1.0×10?7 mol/L. This proposed method has been successfully applied to analyze the actual samples with satisfactory assay results.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号