电化学传感器应用于环境雌激素—壬基酚检测的研究

发布时间：2018-04-24 02:10

本文选题：传感器 + 壬基酚　；参考：《华中科技大学》2012年硕士论文

【摘要】：社会快速进步、工业生产迅猛发展的同时，也给人类的生活带来了越来越多的负面影响。近年来，化学污染问题日趋严重，各大环境问题也被频频曝光。壬基酚（NP）作为公认的环境内分泌干扰物（EEDs），其危害已经引起全世界的广泛关注。壬基酚一旦被排入环境当中，便会长时间存在，并通过生物蓄积作用以及食物链作用将其危害传递、放大。因此建立壬基酚的分析方法对研究其生理作用及制定环境卫生标准都有着极其重要的意义。在众多的检测手段当中，电化学方法因其响应迅速、选择性好、灵敏度高、所需仪器价廉、操作简便、无需复杂的样品前处理过程等而倍受青睐。本论文致力于开发简单、灵敏的电化学传感器并将其应用于水环境和食品相关方面的壬基酚的检测。本论文主要包括以下两方面内容：第一部分：壬基酚在多壁碳纳米管-双十六烷基磷酸复合膜修饰电极上的电化学行为及其测定本部分利用多壁碳纳米管（MWNTs）与双十六烷基磷酸（DHP）混合形成复合膜，覆盖于玻碳电极（GCE）表面来制备直接检测NP的电化学传感器。经过酸处理的MWNTs表面带有负电荷，容易发生团聚，使其表面的活性位点被覆盖掉。DHP分子结构中带有一个亲水性基团和一对疏水性基团（C-H链），其表面亦带有负电荷。当DHP与MWNTs混合后，会对MWNTs起到分散作用，使MWNTs表面因团聚覆盖掉的活性位点暴露出来，增强NP在修饰电极表面的电化学响应。通过条件优化，该传感器对NP响应的线性范围在2.0×10~(-6)mol/L～2.6×10~(-5)mol/L，检测限达6.0×10~(-7)mol/L，应用于环境水质样品中NP的测定，其结果与高效液相色谱法（HPLC）所得结果一致。第二部分：基于十六烷基三甲基溴化铵修饰碳糊电极的壬基酚电化学传感器本部分利用阳离子表面活性剂十六烷基三甲基溴化铵（CTAB）在碳糊电极表面吸附形成CTAB单分子层来制备电化学传感器，增强壬基酚的电化学响应。将石墨粉与粘合剂石蜡油混合制备成碳糊（CP），石蜡油是疏水性粘合剂，，一般对溶液中亲水性物质富集效果较差。通过CTAB长链与碳糊中石蜡油的疏水作用，CTAB在电极表面形成稳定的单分子层。CTAB的疏水特性不但可以改变电极/溶液界面的电化学性能，而且可以增强NP在电极表面的吸附性。实验采用了搅拌的方法进一步增加电极对壬基酚的富集速率，大大缩短了检测时间。在最佳的实验条件下，该电化学传感器对壬基酚有良好的响应，其线性范围在1.0×10-7mol/L～2.5×10~(-5)mol/L，检测限达1.0×10~(-8)mol/L。除了具有令人满意的重现性和稳定性之外，该方法成功的应用于聚氯乙烯（PVC）样品的分析，结果与HPLC法相吻合。
[Abstract]:With the rapid progress of society and the rapid development of industrial production, it has brought more and more negative effects to human life. In recent years, the problem of chemical pollution is becoming more and more serious. As a recognized environmental endocrine disruptor, nonylphenol (NPN) has attracted worldwide attention. Once the nonylphenol is discharged into the environment, it will exist for a long time, and it will be transmitted and amplified by bioaccumulation and food chain action. Therefore, it is of great significance to establish the analytical method of nonylphenol to study its physiological function and to establish environmental hygiene standards. Among the many detection methods, electrochemical method is popular because of its rapid response, good selectivity, high sensitivity, cheap instrument, simple operation and no complicated sample pretreatment process. In this paper, a simple and sensitive electrochemical sensor is developed and applied to the detection of nonylphenol in water environment and food. This thesis mainly includes the following two aspects: The first part: electrochemical behavior and determination of nonylphenol on multiwalled carbon nanotube-cetylphosphoric acid composite film modified electrode In this part, multiwalled carbon nanotubes (MWNTs) and hexadecyl phosphate (DHP) were mixed to form a composite membrane, which was coated on the surface of glassy carbon electrode (GCEE) to prepare electrochemical sensors for direct detection of NP. The surface of acid-treated MWNTs has negative charge and is easy to agglomerate. The active sites on the surface of MWNTs are covered with a hydrophilic group and a pair of hydrophobic groups. When DHP and MWNTs were mixed, MWNTs was dispersed, the active sites of MWNTs surface were exposed by agglomeration, and the electrochemical response of NP on the surface of modified electrode was enhanced. The linear range of NP-response of the sensor is 2.0 脳 10~(-6)mol/L~2.6 脳 10 ~ (10) ~ (-5) mol 路L ~ (-1), and the detection limit is 6.0 脳 10 ~ (10) ~ (-7) mol / L, which has been applied to the determination of NP in environmental water samples. The results are in agreement with those obtained by high performance liquid chromatography (HPLC). Part two: nonylphenol Electrochemical Sensor based on Cetyltrimethylammonium bromide modified carbon paste electrode In this part, CTAB monolayers were prepared by cationic surfactant cetyltrimethylammonium bromide (CTAB) adsorbed on the surface of carbon paste electrode to enhance the electrochemical response of nonylphenol. Carbon paste was prepared by mixing graphite powder with binder paraffin oil, which is a hydrophobic binder and has poor enrichment effect on hydrophilic substances in solution. Through the hydrophobic interaction between CTAB long chain and paraffin oil in carbon paste, the hydrophobic properties of monolayer. CTAB formed on the electrode surface can not only change the electrochemical performance of the electrode / solution interface, but also enhance the adsorption of NP on the electrode surface. The agitation method was used to further increase the enrichment rate of nonylphenol and shorten the detection time. Under the optimum experimental conditions, the electrochemical sensor has a good response to nonylphenol. The linear range is 1.0 脳 10-7mol/L~2.5 脳 10 ~ (10) ~ (-5) mol / L, and the detection limit is 1.0 脳 10 ~ (-1) ~ (-8) 渭 mol 路L ~ (-1) 路L ~ (-1). In addition to the satisfactory reproducibility and stability, the method has been successfully applied to the analysis of PVC / PVC samples. The results are in good agreement with the HPLC method.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP212.2;R134.4

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