【作者】 任小娜；

【导师】 马永钧；

【作者基本信息】 西北师范大学 ， 分析化学， 2008， 硕士

【摘要】 毛细管电泳电致化学发光技术,是当今国际分析化学前沿领域中一种极具潜力的微量分离检测技术,它集成了电泳分离的高效、电化学发光检测的灵敏等特点,主要优势在于:费用低廉、快速分离、样品用量少、污染小。Ru(bpy)32+是电致化学发光分析中应用最广的发光试剂之一,作为一种重要的发光探针分子,Ru(bpy)32+具有水溶性好、化学性质稳定、氧化还原可逆等优点,被广泛应用于环境有害污染物、各种药物成分分析和各种生物活性物质的标记和快速定量检测等方面。然而,在CE-ECL检测中所用电极的表面状况对发光探针分子Ru(bpy)32+的发光效率影响极大,尤其是工作电极被吸附物毒化会严重降低检测的灵敏度和稳定性。类普鲁士蓝类无机多核过渡金属氰化物既具有导体性质又具有聚合物的三维网状结构,而且有极高的化学稳定性、电催化性能、机械强度高、易制备和低成本等特点,以稀土离子代替部分或全部高自旋三价铁离子合成的类普鲁士蓝化学修饰电极仅有极少量报道。因此本工作的主要内容是利用电化学沉积法制备了掺铕的类普鲁士蓝化学修饰铂电极,实验发现该修饰电极对Ru(bpy)32+有良好的催化氧化作用,并在此基础上建立了以Eu-PB修饰电极为工作电极,基于Ru(bpy)32+发光体系上的CE-ECL新分析方法,实现了对中、西药有效成分中一些含有叔胺基团化合物的高灵敏测定。论文的主要研究内容包括以下四部分:第一章综述第一节简单回顾了毛细管电泳(CE)的发展历史、现状和发展趋势,对CE的基本原理、分离模式和检测技术进行了简单介绍。第二节对电致化学发光检测法(ECL)进行了较为全面的综述,重点介绍了Ru(bpy)32+的电致化学发光模式。第三节综述了CE-ECL技术的研究现状以及在中、西药分析中的应用。第四节对化学修饰电极进行了简介,并重点综述了化学修饰电极在提高Ru(bpy)32+的发光效率中的应用。最后介绍了本论文的研究目的和意义。这部分共引用文献124篇。第二章用PB-Eu修饰铂电极改善CE-ECL分析灵敏度的效果评价研究本文探索了将化学修饰电极应用于毛细管电泳-电致化学发光检测法(CE- ECL)以及提高该方法灵敏度的可行性。制备了掺铕的类普鲁士蓝化学修饰(Eu-PB)的铂电极作为工作电极,实验发现该修饰电极在相对较低的检测电位(1.20V vs. Ag/AgCl)对Ru(bpy)32+有良好的催化氧化作用,并呈现出很好的重现性和稳定性。以三丙胺(TPA)和脯氨酸(Pro)为标示分子,对使用Eu-PB/Pt电极后CE-ECL法检测灵敏度的改善效果进行了评价。相比使用裸铂电极的情况,将Eu-PB修饰铂电极应用于CE-ECL体系后,TPA和Pro的发光强度均增加了4倍,线性范围拓宽1个数量级,分别为5×10-10 ~1×10-5 M和1×10-7~1×10-5M。按3倍的信噪比计算,TPA和Pro的检测限分别降至1.29×10-10M和5.30×10-8M。实验结果表明,将化学修饰电极应用于CE-ECL检测系统能明显提高原方法的灵敏度、扩展其适用范围,为基于Ru(bpy)32+发光体系的毛细管电泳电致化学发光检测法拓展了更广阔的应用领域。第三章毛细管电泳-电致化学发光法测定西药洛贝林的研究基于稀土掺杂类普鲁士蓝化学修饰电极对Ru(bpy)32+的电催化氧化可增敏电致发光信号,建立了一种毛细管电泳-电致化学发光测定西药成分洛贝林的新方法。研究了工作电极电位、缓冲液的酸度及其浓度、分离电压和进样时间等实验参数对洛贝林测定的影响。在优化的实验条件下,其浓度线性范围为1.5×10-7 M~1.5×10-4 M,检出限(3σ)为5.0×10-8 M。本法可直接用于注射液和人尿中洛贝林含量的测定,回收率为98.3 %~101.2 %,结果令人满意。第四章毛细管电泳-电致化学发光检测法分离测定中药马尿泡中的托烷类生物碱成分以铕离子掺杂类普鲁士蓝(Eu-PB)化学修饰铂电极为工作电极,采用毛细管电泳-电致化学发光联用法对四种托烷类生物碱成分(如山莨菪碱、东莨菪碱、阿托品和樟柳碱)进行了分离检测。考察了氧化电位值、运行缓冲液酸度、盐浓度和甲醇含量等实验条件对电泳分离效果、检测灵敏度的影响。在优化的实验条件下,以20 mM的磷酸盐(pH 8.0)-7 %甲醇(体积分数)为运行液,各组分在6 min内可达到基线分离,其峰面积测量值的相对标准偏差小于5.0 %,迁移时间的相对标准偏差小于1.1 % ( n= 12)。并将该法成功地应用于测定中药马尿泡根茎中的山莨菪碱和东莨菪碱的含量,其总体平均含量分别为27.8 g/kg、4.43 g/kg。样品的加标回收率为97.8~102 %。更多还原

【Abstract】 Capillary electrophoresis (CE) with electrochemiluminescence detection (ECL) is a micro-quantity separation detection technology having greatest application potential in international analytical chemistry nowadays. It combines the high separative efficiency of CE with the high sensitivity of ECL detection. The main advantages of CE-ECL technique include decreased cost, fast separation, small consumption of samples and less pollution. Tris(2,2’-bipyridyl)ruth enium(II) (Ru(bpy)32+) is one of the most widely used electrochemiluminescence reagents. As an important luminescent probe, Ru(bpy)32+ has some advantages, such as good water soluble, good chemical stability and reversible oxidation-reduction behavior et al. So it has been widely applied to the labelling of environmentally pollutants, various medicines and bioactive substances and fast quantitative determination. However, the surface conditions of working electrode in the CE-ECL detection procedure impact greatly on the luminescence efficiency of Ru(bpy)32+. Especially the sensitivity and stability of determination greatly decreased, when the surface of working electrode was contaminated by adsorbing other substances. Prussian blue analogue not only has conductor nature and three-dimensional network structure of the polymer but also possesses higher chemical stability, finer electrocatalytic performance, higher mechanical strength, easily preparation and lower cost and so on. A few reports about prussian blue analogy chemically modified electrodes are available that are synthesized by rare-earth ions partial or entire instead of high-spin trivalent iron ions in PB analogy crystal lattic.Hence, a platinum electrode modified with Europinum(Ⅲ)-doped prussian blue analogue (Eu-PB) film was prepared by electrochemical deposition in this paper. The experiments revealed that the Eu-PB modified platinum electrode had good catalytic oxidation effects for Ru(bpy)32+. An analytical method based on Eu-PB modified platinum electrode applied to CE-ECL has been established for the determination of active ingredients in western medicine and Chinese herbs, which contain tertiary amine groups in the studied molecular construction. This paper includes four parts: Chapter One ReviewThe first section has revieved the history, current situation and future trend of capillary electrophoresis. The fundamental theory of CE and its isolation mode and detection technology are introduced simply. In the second section, the electrochemiluminescence (ECL) detection is summarized in detail, pay attention to the mode of the electrochemiluminescence of Ru(bpy)32+. The present research of CE-ECL and its application in analysis of traditional Chinese medicines and western medicines are introduced in the third section. The fourth section summarize the chemically modified electrode and pay more attention to the application of chemically modified electrode in improving the luminescence efficiency of Ru(bpy)32+. At last, the purpose and meaning of this work are discussed. Totally 124 references are cited in the chapter one.Chapter Two The study of evaluation on improving analytical sensitivity of CE-ECL using Eu-PB modified platinum electrodeOur work explored the feasibility of improving the sensitivity of CE-ECL detection method by applying chemically modified electrode. An Eu-PB modified platinum electrode was prepared as working electrode, good catalytic oxidation characteristic for Ru(bpy)32+ in the relatively lower potential(1.20 V vs. Ag/AgCl) was revealed and it has shown good reproducibility and stability. Tripropylamine (TPA) and proline (Pro) were made as labelled molecular for the evaluation of CE-ECL system using Eu-PB modified platinum electrode. Compared with bare platinum electrode, the absolute ECL intensity of TPA and Pro increased 3 times and linear range widened one order of magnitude, 5×10-10~1×10-5 M for TPA and 1×10-7~1×10-5M for Pro respectively, when Eu-PB modified platinum electrode was used in CE-ECL system. Based on three times the signal to noise ratio, the detection limits reduced to 1.29×10-10 M for TPA and 5.30×10-8 M for Pro. All experimental datas indicated that the sensitivity of CE-ECL detection system was significantly improved using Eu-PB modified platinum electrode and the CE-ECL detection method could be expanded a broader analytical area.Chapter Three Determination of Lobeline Hydrochloride by Capillary Electrophoresis with Electrochemiluminescence DetectionA new capillary electrophoresis electrochemiluminescence (CE-ECL) method had been developed for the determination of lobeline hydrochloride, which was based Abstract on the fact that the Eu-PB modified platinum electrode exhibited higher electrocatalytic characteristic for Ru(bpy)32+. The effects of several factors such as the applied potential, the acidity and concentration of running buffer, separation voltage and injection time on CE-ECL were investigated. Under the optimum conditions, the ECL intensity was linear with the lobeline hydrochloride concentration in the range of 1.5×10-7 mol/L~1.5×10-4 mol/L. The detection limit (S/N=3) was 5.0×10-8 mol/L and the RSD was 1.3 % for 5.0×10-8 mol/L lobeline ( n = 11). The method had been successfully applied to the determination of lobeline hydrochloride in human urine and injections with satisfactory results. The recoveries were 98.3%~101.2%.Chapter Four Determination of tropane alkaloid components in Przewalskia tangutica Maxim. by capillary electrophoresis with electrochemiluminescence detectionBased on an Eu-PB modified platinum electrode as the working electrode, a method for the simultaneous determination of four tropane alkaloids: anisodamine, scopolamine, atropine and anisodine, by capillary electrophoresis with electrochemiluminescence detection was established. The effects of several factors such as the detection potential, acidity and concentration of running buffer, and concentration of additive methanol for CE-ECL were investigated for the improvement of separation ability and detective limit. Under the optimum conditions, these four components could be separated each other fully in a 20 mmol/L phosphate + 7 % (V /V) methanol within 6 min. The relative standard deviations of peak area and migration time were less than 5.0 % and 1.1 % (n = 12) respectively for all four compounds. Thus, the method had been successfully applied to the determination of anisodamine, scopolamine in Przewalskia tangutica Maxim.. The overall average amount of 27.8 g/kg anisodamine and 4.43 g/kg scopolamine were found in the herbal rootstalk sample. The recoveries of two tropane alkaloids were 97.8~102 %.更多还原