基于离子选择电极的磷酸根检测的研究

发布时间：2018-09-14 08:11

【摘要】：磷是生物不可缺少的重要元素,但是过量的磷排入到江河湖泊中,会使水体受到严重的污染,出现水体富营养化的现象,而磷的含量决定了水体的富营养化程度。因此磷的含量是衡量水质好坏的一项重要指标,然而目前使用的磷酸根检测方法大多需要添加一些化学试剂,检测时间较长,且检测过后的溶液会对环境造成二次污染。电化学分析法中的离子选择电极法检测过程中不添加化学试剂,避免了对环境的二次污染,而且该方法还具有简单方便、分析速度快、成本低、灵敏度高等优点。因此本文依据离子选择电极原理,开发了磷酸根离子选择电极,主要研究内容如下：(1)研究了一种液态磷酸根离子选择电极,该电极以层状镁铝复合金属氧化物为活性物质,三十二烷基甲基氯化铵为离子添加剂,2-硝基苯辛醚为增塑剂。研究了电极敏感膜的组成比例、增塑剂、内充液对电极性能的影响,并对电极的选择性,响应时间等参数进行考察。结果得出在最佳制成电极的条件下,电极在磷酸二氢根浓度为10-1～10-4mol/L的线性范围有较好的能斯特响应曲线,电极的斜率达到-27.3mV/dec,电极的检测下限为9.22×10-5mol/L.(2)利用电化学法中的恒电流法,制作了掺杂钴-氧化钴的聚苯胺修饰玻碳电极。研究了聚合条件及钴离子含量对电极的影响,在最佳条件下制成的电极在磷酸二氢根浓度为10-1～10-4mol/L的范围有较好的线性,检测下限为9.3×10-5mol/L,响应时间小于一分钟,且具有较好的选择性,稳定性和良好的重复性。(3)开发了具有双层膜结构的磷酸根离子选择电极。该电极以玻碳为基底电极,掺杂钴-氧化钻的聚苯胺为中间体,层状镁铝复合金属氧化物PVC膜为敏感膜,具有较高的响应斜率-32.3mV/dec,较低的检测下限7.65×10-5mol/L,电极响应时间较短,稳定性、抗干扰能力较强,同时具有更好的机械性能和相对较长的使用时间。
[Abstract]:Phosphorus is an indispensable and important element in living things, but excessive phosphorus discharged into rivers and lakes will cause serious pollution and eutrophication of water, and the content of phosphorus determines the degree of eutrophication. Therefore, the content of phosphorus is an important index to measure the quality of water quality. However, most of the methods used at present need to add some chemical reagents, the detection time is longer, and the detected solution will cause secondary pollution to the environment. The ion selective electrode method in electrochemical analysis can avoid the secondary pollution of the environment by adding no chemical reagent. Moreover, the method is simple, convenient, fast, low cost and high sensitivity. Therefore, based on the principle of ion selective electrode, a phosphate ion selective electrode has been developed. The main contents are as follows: (1) A liquid phosphate ion selective electrode is studied. 32 alkyl methyl ammonium chloride as ionic additive 2-nitrophenyl octyl ether as plasticizer. The effects of the composition of the electrode sensitive film, plasticizer and liquid on the performance of the electrode were studied. The selectivity and response time of the electrode were also investigated. The results show that the electrode has a good Nernst response curve when the concentration of dihydrogen phosphate is 10-1~10-4mol/L. The slope of electrode is -27.3 MV / L and the detection limit of electrode is 9.22 脳 10 ~ (-5) mol 路L ~ (-1) 路L ~ (2). (2) the constant current method is used in electrochemical method. Polyaniline modified glassy carbon electrode doped with cobalt-cobalt oxide was prepared. The effects of polymerization conditions and cobalt ion content on the electrode were studied. Under the optimum conditions, the electrode had a good linearity in the range of dihydrogen phosphate concentration of 10-1~10-4mol/L, the detection limit was 9.3 脳 10 ~ (-5) mol / L, and the response time was less than one minute. It has good selectivity, stability and reproducibility. (3) the phosphate ion selective electrode with double-layer membrane structure has been developed. The electrode uses glassy carbon as substrate electrode, Polyaniline doped with cobalt oxide drill as intermediate, layered magnesia-aluminum composite metal oxide PVC film as sensitive film, has a high response slope of -32.3mV / L, low detection limit of 7.65 脳 10 ~ (-5) mol / L 路L ~ (-1), short response time and stability. Strong anti-jamming ability, at the same time with better mechanical properties and relatively long time to use.
【学位授予单位】：江南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X832;O657.1

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