节点文献
毛细管电泳—电化学检测联用技术及其应用研究
Study on Capillary Electrophoresis with Electrochemical Detection and Its Applications
【作者】 石雪；
【导师】 叶建农；
【作者基本信息】 华东师范大学 ， 分析化学， 2009， 硕士
【摘要】 第一章绪论毛细管电泳具有分离效率高,快速和所需样品量少等特点。在生物化学、分子生物学、药物化学、食品化学、环境化学和医学等许多领域,有着广阔的应用前景。在绪论中对毛细管电泳做了概述,介绍了毛细管电泳的设备和基本原理,并且对毛细管电泳-电化学检测（CE-ED）进行了较为全面的综述和展望。根据本论文的研究内容,重点综述了毛细管电泳在药物分析,临床疾病诊断化妆品安全控制和物化常数测定等方面的应用研究。本论文采用CE-ED技术,测定了竹叶和竹叶茶中的活性成分,对竹叶资源开发具有一定的指导意义;并将毛细管电泳应用范围延伸到临床指标物的测定,应用于运动量的诊断;对比了市面销售牙膏中的二甘醇含量,提供了一种新的日用品安全控制方法;还测定了水杨醇和苯酚的pKa值,把毛细管电泳应用于物化常数的测定,大大拓展了CE-ED的应用范围。第二章毛细管电泳-电化学检测法分析竹叶及竹叶茶中的活性成分用毛细管区带电泳-电化学检测法（CE-ED）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、香草酸和咖啡酸等物质的含量,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300μm的碳圆盘电极为检测电极,电极电位为+0.95 V（vs.SCE）,在60mmol/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,最低检测限范围为1.9×10-8～9.8×10-8g/mL。该法用于实际样品的分析,结果令人满意。第三章毛细管电泳—电化学检测法研究运动对尿样和唾液中肌酐和尿酸含量变化的影响采用毛细管电泳—电化学检测法（CE-ED）研究了有氧运动对唾液和尿样中肌酐和尿酸含量变化的影响。研究了电极电位、运行液浓度、分离电压等参数对分离检测效果的影响。在优化条件下,以直径450μm的铜圆盘电极为工作电极,电极电位为+0.655V（vs.SCE）,在pH9.24、20mmol/L的硼酸、70mmol/L SDS的运行缓冲液中,上述三组分在22min内可实现基线分离。肌酐和尿酸的浓度分别在8.83×10-6～1.76×10-3mol/L、5.94×10-7～2.38×10-3mol/L的范围内与峰电流呈良好线性关系,肌酐和尿酸的检测限分别为3.6μmol/L和0.86μmol/L。此方法成功地运用于实际样品的测定,研究结果表明,在有氧运动后,唾液中肌酐的浓度下降,尿酸的浓度上升;而在尿样中,肌酐和尿酸的浓度都上升。第四章毛细管电泳一电化学检测法测定牙膏中的二甘醇本部分运用了毛细管电泳一电化学检测法（CE-ED）对牙膏中的违禁成分——二甘醇进行分析测定。研究中主要考察了电极电位、进样时间、分离电压、运行液的pH值等因素对二甘醇、丙二醇和丙三醇的分离测定结果的影响,并探索了二甘醇的最佳检测分析条件。使用长为75cm,直径为25μum的石英毛细管为分离通道,300μm铜电极作为工作电极,在pH9.2硼砂运行缓冲体系中,牙膏中通常使用的保湿剂二甘醇、丙二醇、丙三醇三组分在20min内实现基线分离,具有很好的分离和检测效果。二甘醇的检测限为1.45×10-6g/mL。实验中对市售不同品牌、不同批号的牙膏进行二甘醇含量检测,回收率在97～103%之间。第五章毛细管电泳电化学检测法测定水杨醇和苯酚的PKa本文利用毛细管电泳.电化学检测法（CE-ED）的高灵敏度,测定水杨醇和苯酚的电离常数（pKa）。电离常数（pKa）是弱酸、弱碱的基本性质,分子和电离离子的理化性质往往存在很大差异。实验中考察了不同pH值下水杨醇和苯酚的有效淌度随迁移时间改变的变化情况,结果表明,有效淌度随pH值的升高而增大。实验中建立了pH值和有效淌度的函数关系。由此推算水杨醇和苯酚的电离常数分别为9.94、9.96,与文献中的数据相吻合。结果表明CE-ED能简单方便的测定物化常数,拓宽了CE-ED的应用范围。
【Abstract】 Capillary Electrophoresis（CE） is becoming increasingly recognized as one of the most important separation techniques in recent twenty years due to its speed, efficiency,reproducibility,ultra-small sample volume,and ease of Clearing up the contaminants.Because the theoretical plate number is greatly developed to tens of thousands and even millions,and the volume of sample injection reaches nano milliliter lever in CE analysis,it has been studied and applied to most analytical areas. Electrochemical detection is usually more sensitive than UV detection for electroactive species,and has many advantages when it combines with CE,CE-ED offers high sensitivity and good selectivity for electroactive species.The goal of this thesis is to explore some applications in Chinese traditional medicine analysis,human body fluid analysis,control of cosmetic safety and determination of physicochemical constant by CE-ED.The major content is as follows:1.PrefaceThe development of CE,the basic theories of CE,the CE detectors,the studies and applications of CE-ED are introduced simply.The goal and significance of this thesis are introduced too.2.Determination of Active Components in Bamboo Leaves and Bamboo-leaf Tea by Capillary Electrophoresis with Electrochemical DetectionA simultaneous determination of vanillin,trans-ferulic acid, p-hydroxybenzaldehyde,p-coumaric acid,vanillic acid,4-hydroxybenzoic acid and caffeic acid in five different kinds of bamboo leaves and bamboo-leaf tea by capillary zone electrophoresis with electrochemical detection（CE-ED） was reported.The effects of several important factors were investigated to acquire the optimum analysis conditions.A 300μm diameter carbon disc electrode was used as the working electrode positioned carefully opposite the outlet of capillary at potential of +0.95 V （vs.SCE）.The analytes could be well separated within 22 min at a separation voltage of 16 kV in a 60 mmol/L borate buffer（pH＝8.7）.There is excellent linearity between peak.current and concentration of seven analytes over two or three orders of magnitude with the detection limits（S/N＝3） ranging from 1.9×10-8 g/mL to 9.8x10-8 g/mL.The proposed method has been successfully applied to the analysis of real samples with satisfactory results.3.CE determination of creatinine and uric acid in saliva and uric acid during excise.A simple and reliable method based on capillary electrophoresis with electrochemical detection（CE-ED） was applied to study the effect of aerobic exercises on creatinine and uric acid concentration in saliva and urine.The pH value, the running buffer concentration,the SDS concentration,separation voltage,injection time and the potential applied to the working electrode were investigated to find the optimum conditions.The detection limits（S/N＝3） for creatinine and uric acid were 3.6μmol/L and 0.86μmol/L,respectively.This method was successfully first used in the rapid analysis of creatinine and uric acid in saliva samples.After aerobic exercises, creatinine concentration decreased,and uric acid concentration increased in saliva.In urine,the concentration of creatinine and uric acid both increased after exercise.4.Determination of diethylene glycol in toothpaste by capillary electrophoresis with electrochemical detection.A capillary electrophoresis technique with electrochemical detection（CE-ED） for the determination of diethylene glycol（DEG） in toothpaste was described.Effects of several factors,such as the pH value and the concentration of the running buffer, the separation voltage,the injection time and the potential applied to the working electrode,were investigated to find the optimum conditions.With a length of 75 cm, 25μm inner diameter fused-silica capillary,well-defined separation of diethylene glycol from propylene glycol and glycerol was achieved in the running buffer.While operated in a wall-jet configuration,a 300μm copper disc electrode used as the working electrode,the applied potential was +0.65 V（vs.SCE）,the separation voltage was 16 kV,the above three analytes could be well separated in an 80 mmol/1 borate buffer（pH＝9.2）.The linear range of DEG was from 8.4×10-4 g/mL to 4.2×10-6 g/mL. Notably,the DEG detection limit（S/N＝3） of 1.5×10-6 g/mL could meet the safety criterion of this compound.This method was successfully used in the rapid analysis of DEG in several toothpaste samples.The average recoveries of 96.9%-102.9% indicated that the experimental results were satisfactory.5.Determination of pKa value of salicyl alcohol by capillary electrophoresis with electrochemical detectionA simple and rapid method based on capillary electrophoresis with amperometric detection（CE-AD） to calculate the dissociation constant of salicyl alcohol and phenol is described.The effects of several factors,such as the potential applied to the working electrode,injection time,and separation voltage,were investigate to find the optimum conditions for pKa determination.Operating in a wall-jet configuration,a 300μm carbon disk electrode used as the working electrode exhibited good response at 0.86 V（vs.SCE） for salicyl alcohol and phenol.The effective mobilities of salicyl alcohol at different temperatures were determined by monitoring the migration time changes of salicyl alcohol and phenol.The dissociation constants of salicyl alcohol and phenol were calculated to be 9.94 and 9.96,respectively,which are in good agreement with the literature.