| In recent years, social events and trade disputes which caused by pesticide residues had emerged one after another. And the widely using of the carbamat pesticides gives rise to many food safety incidentsfrequently. Meanwhile, Europe, the U.S.,Japan and other developed countries had raised their pesticide inspection standards which lead to enormous crisis of our country agricultural exports. So the carbamat pesticides hasbecome the key of detection object in the agricultural products processing, circulation and commerce. Now, the mainly methods of detection carbamate pesticide contain Enzyme inhibition method,Immune method,Chromatographic method, etc. Because the long analysis cycle, operating too trival,cannot fit for carbamate pesticide detection conveniently; On the other hand, we need a field analysis which can be used for the carbamate pesticide monitoring and the methods of testing analysis devices. Chemically modified electrode sensors have a high cost-effective, dexterous and other characteristics, using widely in the various components of on-line analysis. Furthermore, the amino acids is a potential excellent chemical modifier with its good electrochemical activity, stable and reliable performance, if cooperating with metal ions composite modified electrodes, they can get response with high accuracy immediately. So, sensitivity good chemically modified electrode sensors must dedicated to carbamate pesticide detection.This article adopts amino acids-metal ion films, as compound modifier, to prepare for carbamate pesticide chemically modified electrode sensors. In this way, they can be applied to carbamate pesticide detection directly.The basic content of this article as follow:1. We took L-lysine-nickel films as modifier, using electrochemical polymerization to modify it to the surface of the glassy carbon electrode, then prepared L-lysine-nickel films modified electrode, and optimized its decorate conditions by the response surface design test, showing that the best modification conditions is:5.0×10-5mol/L L-lysine-nickel phosphat buffer solution (pH= 7.0) in-1.0～1.0V range, sweep speed for 100mV/s, circulation scanning 15 laps. This paper made a study of electrochemical acts of carbofuran on the L-lysine-nickel films modified electrode. The results through studying by the bottom of the selection, pH influence, scanning rate, the linear range, and system adsorption etc were that in 0.2mol/L NH3-NH4CI Solution (pH=8.5), carbofuran have obvious oxidation peaks in Cyclic voltammograms, and the carbofuran content in 5.0×10-6～8.0×10-5mol/L range have a good linear relationship with its Oxidation peak current. Regression equations of working curve is I=0.4189LogC+13.44(mol/L), linear correlation coefficient is 0.9981. This method has the advantages as fast, high sensitivity, the results are stable, etc.2. Preparation L-tryptophan copper films modified electrodes in glassy carbon electrode by electrochemical polymerization. and study its propoxuron circulation voltammetric behavior in 0.1mol/L pH=5.7 HAc-NaAc buffer solution. There is a good linear relationship between Peak current and propoxuron, the linear regression equation is ipa=196.4c+32.60, linear correlation coefficient is 0.9993,the same time, we have done the water sampling and analysis experiments, discovering the recovery is good.3. Using adsorption to L-cysteine iron films modified electrodes and research in the preparation of conditions, We used the sensor been prepared to detection pirimicarb, and got the best detection conditions: clark-lubs solution (pH=4.5) in -1.0～1.2V potential scope, sweep speed for 100mV/s. In this test conditions, there is a good linear relationship between electrode response and pirimicarb in 1.0×10-4～2.0×10-5mol/L rang, the linear regression equation is ipa=4.457c+28.76, linear correlation coefficient is 0.9994. |
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