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1.
芦荟大黄素的电化学研究   总被引:8,自引:1,他引:8  
用单扫示波极谱法研究了芦荟大黄素的电化学行为。在5%Na2CO3+5%NaOH(9+1)底液中,芦荟大黄素于-0.84V(P1)和-0.97V(P2)处产生两个示波极谱峰,利用P1可测定芦荟大黄素,线性范围为 0.11-24mg/L和3.0-28.6mg/L,检测限为0.06mg/L。将该法应用于中药大黄中的芦荟大黄素的测定,结果满意。另外,讨论了芦荟大黄素清除由邻苯三酚自氧化产生的超氧自由基(O2)的作用。  相似文献   
2.
本文报道了一种用毛细管区带电泳法(CZE)分离与测定对氨基苯甲酸、对羟基苯甲酸及磺胺类药物的新方法.电泳条件为:用 20mmol/L硼砂-20mmol/L H_3PO_4-20 mmol/Lβ-环糊精-4%乙醇(pH 7.0)作电泳液,L-抗坏血酸为内标,280nm为检测波长,样品由电进样方式(10kV/10s)引入毛细管(51.2 cm×50μm i.d.,有效分离长度为 38.5 cm).在24.5°C下,6 min内三者可达基线分离(电泳电压 25kV),且在一定范围内可进行定量分析,保留时间(Tr)及A_(样品)/A_(内标)的RSD值分别小于1.0%和5.0%.本法的建立为研究这三者共存于高等动物及微生物体内时的生理作用提供了一种可共选择的新方法.  相似文献   
3.
用单扫示波极谱法,在生理盐水底液中,25℃时邻硝基对甲基苯胺于-0.82±0.01伏(SC)处有一良好的二阶导数还原峰,浓度为2×10(-8)-1×10(-5)mol/L时,与峰电流呈良好的线性关系,可作分析测定,检测限为1×10-8mol/L。许多无机离子不干扰测定。此外,还证明其电极过程为吸附过程,n=4,提出了电极反应机理。  相似文献   
4.
用高效液相色谱法优化苯与对氯氯苄烷基化反应催化剂刘红霞张书胜袁倬斌*(郑州大学分析测试中心郑州)(中国科学技术大学研究生院北京100039)关键词氯-二苯甲烷,制备,三氯化铝,硝基苯,硝基乙烷,高效液相色谱法1997-03-31收稿,1997-09-...  相似文献   
5.
6.
Summary Capillary electrophoresis-amperometric detection is evaluated for simultaneous determination of rutin and forsythin. The cyclic voltammogram, hydrodynamic voltammogram, effect of pH, buffer concentration and SDS, and percent organic modifier on separation and detection were studied. Conditions were optimized as follows: 1.2 V detection potential; separation at 12 kV; 5 s at 15 kV for sample injection time and sample injection voltage; mobile phase 20 mM boric acid buffer; pH 8.4, containing 40 mM SDS and 10% (v/v) acetontrile. The method gave low detection limit as 0.001 mg mL−1 and 0.0005 mg mL−1 (S/N=3), wide linear range 0.005–0.5 mg mL−1 for rutin and forsythin, respectively. The relative standard deviations of peak current and migration time for 8 consecutive injections of the standard solution containing 0.1 mg mL−1 each compound were 4.78%, 3.63% and 6.40%, 2.95% for rutin and forsythin, respectively. In addition, levels of the two compounds in traditional Chinese herbal drugs were easily determined.  相似文献   
7.
Sun  Wenhua  Dong  Yalei  Cui  Hong  Zhao  Hong  He  Yujian  Ding  Yongsheng  Li  Xiangjun  Yuan  Zhuobin 《Chromatographia》2014,77(11):821-828

A newly-developed method of complete separation and sensitive determination of o-, m-, and p-aminobenzoic acid isomers was achieved by combining open-tubular columns for capillary electrochromatography (OT-CEC) and online sample stacking. In this study, spherical gold nanoparticles were modified by a covalent attachment of mono-6-thio-β-cyclodextrin, and OT-CEC was formed by immobilizing cyclodextrin-modified gold nanoparticles (CD-AuNP) on prederivatized 3-mercaptopropyl-trimethoxysilane fused-silica capillaries. Based on the theory of moving chemical reaction boundary, effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were optimized. The optimized separations were carried out in 58 mmol/L HAc buffer at pH 3.0 using a capillary coated with CD-AuNP, while the optimized concentration was carried out in 50 mmol/L disodium hydrogen phosphate (pH 9.5). The linear ranges for m-, p-, and o-aminobenzoic acid were from 5.0 × 10−4–0.1, 5.0 × 10−4–0.1 and 1.0 × 10−4–0.1 mmol/L, respectively. And the detection limits (S/N = 3) were as low as 8.22 × 10−5, 8.21 × 10−5, and 3.76 × 10−5 mmol/L for m-, p-, and o-aminobenzoic acid, respectively. The run-to-run, day-to-day, and column-to-column reproducibilities of migration time were satisfactory with relative standard deviation values of less than 4.5 % in all cases. This method was successfully used in determining procaine hydrochloride injection sample with recoveries in the range of 96.1–106.6 % and relative standard deviations less than 5.0 %.

  相似文献   
8.
A newly-developed method of complete separation and sensitive determination of o-, m-, and p-aminobenzoic acid isomers was achieved by combining open-tubular columns for capillary electrochromatography (OT-CEC) and online sample stacking. In this study, spherical gold nanoparticles were modified by a covalent attachment of mono-6-thio-β-cyclodextrin, and OT-CEC was formed by immobilizing cyclodextrin-modified gold nanoparticles (CD-AuNP) on prederivatized 3-mercaptopropyl-trimethoxysilane fused-silica capillaries. Based on the theory of moving chemical reaction boundary, effects of several important factors such as the pH and concentration of running buffer and the conditions of stacking analytes were optimized. The optimized separations were carried out in 58 mmol/L HAc buffer at pH 3.0 using a capillary coated with CD-AuNP, while the optimized concentration was carried out in 50 mmol/L disodium hydrogen phosphate (pH 9.5). The linear ranges for m-, p-, and o-aminobenzoic acid were from 5.0 × 10?4–0.1, 5.0 × 10?4–0.1 and 1.0 × 10?4–0.1 mmol/L, respectively. And the detection limits (S/N = 3) were as low as 8.22 × 10?5, 8.21 × 10?5, and 3.76 × 10?5 mmol/L for m-, p-, and o-aminobenzoic acid, respectively. The run-to-run, day-to-day, and column-to-column reproducibilities of migration time were satisfactory with relative standard deviation values of less than 4.5 % in all cases. This method was successfully used in determining procaine hydrochloride injection sample with recoveries in the range of 96.1–106.6 % and relative standard deviations less than 5.0 %.  相似文献   
9.
中国化学会第八届有机分析学术交流会介绍袁倬斌(中国科技大学研究生院北京100039)IntroductionoftheCCS8thConferenceonOrganicAnalysisChineseChemicalSocietyYuanZhuobin...  相似文献   
10.
陈勇  杨新  韩凤梅  袁倬斌 《分析化学》1999,27(6):694-696
研究了影响毛细管区带电泳激光诱导荧光间接检测环腺苷单磷酸和环鸟苷单磷酸的实验条件.cAMP和cGMP的线性范围分别为30~500mg/L和15~500mg/L,其最低检测限分别为9.0mg/L和0.5mg/L;当浓度为125mg/L时,cAMP和cGMP峰面积的RSD为4.45%和6.21%(n=4);其迁移时间的日间RSD分别为2.92%和2.04%(n=5)  相似文献   
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