| M-Dinitrobenzene as the intermediates of industrial synthesis,its widely used in printing and dyeing,pesticide,textile and other chemical industry.But m-dinitrobenzene may caused serious pollution through the production and discharge of waste liquid,storage,transportation,use and many other links enter the environment that harm to human health.Nitrofurantoin is an antibacterial drug of nitrofuran antibiotics.It can be also used as feed medicine additive,but it was found to have strong mutagenicity and carcinogenicity in animal cells later.In order to ensure food safety,the use of such drugs have been fully disable.Therefore,detection of m-Dinitrobenzene and nitrofurantoin is necessary.The article prepared poly o-aminophen-olelectro chemical modified electrode sensor and study the polymerization conditions and electro-chemical properties of its polymer film and applied to detect two kinds of material.This paper mainly carried out by the following three aspects:1.This paper had a detailed study the electrochemical polymerization conditions of O-aminophenol and the electrochemical properties of its polymer film by cyclic voltammetry.Experimental results show that the maximum potential of cyclic voltammetry have great impact on the process and product of the electrochemical polymerization of OAP in strong acid medium.When pH?3.0,maximum potential?0.5 V,OAP cannot occur the effective electrode reaction on substrate electrode surface and also can't form effective electrodeposition.When 0.6 V?maximum potential?0.7 V OAP can occur reversible electrode reaction and to form the electroactive sediment on the surface of the electrode.When0.8 V?maximum potential?1.0 V,OAP electric polymerization reaction on the electrode surface can occur and form the electroactive polymer thin film.When maximum potential?1.2 V,OAP electrical inert polymer film electrode reaction can occur.Also studied electrochemical properties of the three kinds of modified electrode were characterized by electrochemical impedance spectroscopy and cyclic voltammetry.2.The poly-o-aminophenol modified graphite electrode was prepared by electropoly-merization,and the modified electrode exhibited a remarkable electrocatalysis on electroredu-ction of m-dibitrobenzene,so a new determination method of m-dibitrobenzene was established by cyclic voltammetry.M-dibitrobenzene has a sensitive reduction peak at-0.676V in the phosphate buffer?pH 12.00?,and the peak current showed good linear relationship with concentration of m-dibitrobenzene in the range from 5.00×10-77 to 6.00×10-55 mol/L.The method was applied to determination of m-dibitrobenzene in seawater with the recovery rate of 105.9%to 108.5%.Measured by chronocoulometry,M-dibitrobenzene based on the modified electrode was occurring one proton and two electrons transfer controlled by the diffusion and adsorption of irreversible electrode process.3.The graphite electrode modified with poly-o-aminophenol and the electrode has catalytic effect of electrochemical reduction of nitrofurantoin.A new method of determination of nitrofurantoin was established by linear sweep voltammetry.Nitrofurantoin has a sensitive reduction peak at-0.633 V in the phosphate buffer?pH 12.00?,and reduction peak current has a good linear relationship with concentration of nitrofurantoin in the range from 8.00×10-7to 3.00×10-55 mol/L.The method was applied for nitrofurantoin determination in urine and recovery these samples was from 95.5%106.0%.Preliminary study on the reaction mechanism of nitrofurantoin on modified electrode,involving two electrons transfer and two protons diffusion controlled irreversible electrode process. |
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