摘要:硝酸盐含量在健康和环境保护领域受到极高的关注。硝酸盐被大量的用作 与食品防腐和农业施肥中，因此人类活动如农业和工业产生的废水，会导致水资源中硝酸盐浓度的增加。硝酸盐在消化系统反应变成成亚硝酸盐并且在食物中生物还原。亚硝酸盐可以和血红蛋白发生不可逆反应从而结合为高铁血红蛋白使得血容量减少输送氧气。另外仲胺从胃中的亚硝酸胺中来，它的存在可能引起癌症，因此，硝酸盐含量标准被作为环境污染和食品管制的指标。已经发表了很多测定硝酸盐方法，例如光谱法，离子色谱法和毛细管电泳，这些技术十分费力并且需要大量的化学试剂。由于电化学的优势在于响应快速，操作不复杂，价格低。所以，电化学方法被方便地应用于硝酸盐测定。电化学运用硝酸盐在电极表面还原的这一特性来检测硝酸盐的含量，但是由于电极动力学非常慢，导致硝酸盐无法直接在裸电极上被检测。因为这个原因许多发表的论文报道用传导性表面，修饰不同活泼金属来克服电极动力学慢的问题同时也解决了易污染问题和析氢电位过高问题。随着如今不断增长的修饰不同活泼金属，例如金，铂，钯和银研究工作，其中特别是银纳米颗粒和银基涂料已经发现了数不清的应用，由于他们将有用属性给电极的表面，让电极表面拥有良好的导热性和导电性，耐化学性，杀菌和催化活性。71930

本文通过比对裸玻碳电极和用银纳米颗粒修饰的玻碳电极，选用合适的电极，进行水中硝酸盐的测定，并且建立用电化学测定水中硝酸盐的方法。

毕业论文关键词：银纳米颗粒，玻碳电极，硝酸盐

Carbon electrodes decorated with silver nanoparticles for the determination of nitrite in environmental water

Abstract: Nitrate is of high concern in the fields of health and environmental protection。 Nitrates are largely employed as food preservatives and fertilizing agents but the wastewaters from anthropogenic activities, as agriculture and industry, are causing increasing contamination of water resources for human consumption。  Nitrate will reduction to nitrite in the digestive system and by microbial reduction in food products Nitrites can react irreversibly with hemoglobin thus producing methemoglobin which reduces blood capacity to transport oxygen; furthermore, in presence of secondary amines, they form N-nitrosamines in the stomach, which are likely to cause stomach cancer。 Thus, it appears that the levels of nitrates can be considered as indicators for environmental pollution and food control。 Many methods for the determination of nitrates, based on spectroscopy, ion chromatography, capillary electrophoresis have been published。 In addition to these techniques, which can be laborious and require chemical reagents, the electrochemical approaches offer the advantages of rapid response, simple operationsimple experimental design, inexpensive instrumentation and safer procedure。 The electrochemical methods have been conveniently applied Nitrate reduction is thermo-dynamically favored nevertheless the electrode kinetics is very slow。 For this reason most of the published papers have reported the use of conductive surfaces modified with different active materials in order to overcome the problems due to fouling and high overpotential。  With dramatically increasing research work of modified various active metal ion such as Au, Pt, Pd and Ag,In particular, Ag nanoparticles (AgNPs) and Ag-based coatings have found numerous applications since they lend useful properties to the coated surfaces, such as good thermal and electrical conductivity, chemical resistance, bactericidal and catalytic activity

In this paper，to choose the suitable electrode, we compare bare GC to the GC electrode which have modified  Ag nanoparticles。 Then establish a electrochemical methods to determine the nitrate。