Study On Detecting Wheat Pesticide Residues Based On SERS Technology

Wheat plays an important role in the foreign trade of agricultural products in China.However,in recent years,due to the excessive use of pesticides,food safety problems caused by excessive pesticide residues often occur,and the problem of pesticide residues is increasingly serious.Therefore,effective control of pesticide residues in agricultural products is worth our attention and discussion.In this thesis,surface-enhanced Raman spectroscopy(SERS)technology was used to rapidly detect pesticide residues in wheat.Compared with the traditional method,the spectral detection technology has the advantages of high sensitivity,high detection efficiency and simple operation,which overcomes the defects of the traditional method and is widely used in food detection.The main contents of this paper are as follows:Surface enhanced Raman detection technology was used to detect pesticide residues in wheat for imidacloprid,methyl chlorpyrifos and chlorpyrifos.Firstly,Raman spectra were collected from standard pesticide solutions of different concentrations to determine Raman characteristic peaks for analysis of experimental results.Then wheat containing different concentrations of pesticide to Raman spectroscopy analysis,through the analysis of samples with different concentration,to obtain the characteristic spectrum data,in order to further make the model has better accuracy and prediction effect,respectively,set up linear regression prediction,PLS,SVR model,the experimental results show that the used in using the SERS technology to detect imidacloprid pesticide residues in wheat,the predicted results of SVR model is superior to the other model method,the real value and predictive value of correlation coefficient of 99.93%,the lowest of imidacloprid pesticide residues in wheat concentration of 1 mg/kg;In the rapid detection of pesticide residues of methyl chlorpyrifos in wheat,the correlation coefficient between the true value and the predicted value in the SVR model was 99.98%,and the minimum concentration ofpesticide residues of methyl chlorpyrifos in wheat was up to 0.85mg/kg.In the rapid detection of pesticide residues of chlorpyrifos poisoning in wheat using SERS technology,the correlation coefficient between the true value and the predicted value in the SVR model was 99.95%,and the minimum pesticide residues concentration of chlorpyrifos poisoning in wheat could reach 0.98mg/kg.Through analysis and comparison,support vector machine(SVM)model has a high accuracy in the predicted value,which can realize the rapid and accurate qualitative and quantitative analysis of pesticide residues in wheat,so as to detect wheat...