Determination Of Malachite Green In Environmental Water By Polarography And Molecularly Imprinted Electrode

Malachite green(MG)is a kind of triphenyl methane fungicide,which has been widely used in aquaculture because of its high efficiency and low cost in the prevention and controlling of aquatic products.However,the methylene and methylene linked to benzene in the molecule are affected by the benzene ring,which has high reactive activity and can produce three benzyl free radicals.The metabolites of these compounds enter the nucleus of the human body and destroy the DNA and cause the cell carcinogenesis.Although the use of MG has such a large safety risk and it has already been included in the forbidden drug at home and abroad,it is still in aquaculture because of the lack of cheap and effective alternative drugs.The main way for MG to enter the human body is by eating aquatic products,such as fish,shrimp,and other aquatic products containing MG,and drinking water.It is of great importance to establish a fast and convenient method for detecting MG in water for health consideration and supervision of the quality of aquatic products.Electrochemical analysis is widely applied in the field of pollutant detection because of its low cost,simple detection principle and convenient operation.The electrochemical sensor has been prepared by molecular imprinting technology,which is fully matched with the template molecule on the space structure and the binding site.The modified molecular imprinting has become a hot spot in the rapid environmental detection,while the polarography has a wider potential window than the solid electrode,which is superior to the solid electrode.The stability and the analysis cost are low,the analysis operation is simple,and it is suitable for the grassroots units to detect and use.To sum up.In this study,polarography and molecularly imprinted electrode have been established to provide the methods for the determination of MG.The main contents of the study are as follows:1.Based on the fluorescein in the B-R buffer solution of pH=7.0,a sensitive reduction peak can be produced,and the existence of MG will reduce the peak current of the fluorescein,and a significant linear relationship with the concentration of MG.A new method for the determination of MG in water is established.In this system,the starting potential is-0.40V,the peak potential is-0.85V(vs.SCE),the concentration of MG is linearly related to the peak current over the range of 20 g/L~120 g/L,and the detection limit is 7.5 g/L.The detection in environmental water samples by the method of MG,the recovery was 90.45%~105.6%.2.The nano gold polypyrrole molecularly imprinted modified glassy carbon electrode(MG-MIPPy/AuNPs/GCE)was prepared by electropolymerization of pyrrole as a monomer and MG on the glassy carbon electrode,and the potassium ferricyanide was used as an electrochemical probe after the imprinting molecule was eluted.According to the significant correlation between the change of probe peak current and the content of MG,the content of MG is indirectly determined.Under the best experimental conditions,the negative pair of MG has a good linear relationship with the difference of the difference between 1 and 1000 g/L.The linear correlation is R~2=0.9923 and the detection limit is 0.0130 g/L.The method is used to detect the actual sample and the recovery rate is 98.82%to 103.1%,and the result is stasfactroy.