Detection And Analysis Of Pesticide Residues In Fruit Skin Based On Raman Spectroscopy

This paper, by regarding apple and pear as objects of research and trichlorphon pesticide as theobject of test, has made an experimental research of residue of trichlorphon on surface of appleand pear with Raman spectroscopy detection technique. In general, the completed contentincludes:1. Through applying LabRAM HR800equipment, this paper has determined that the wavelength, grating, gathering time and gathering times of laser of Raman spectroscopy for samplingpear and apple are473mm,1800,2s and3respectively.2. Through analyzing with adjacent averaging method, Savizkv-Golay method, medianmethod and wavelet denoising method, this paper has attained that signal to noise ratio processedwith DB and bior of wavelet denosing method is18.542higher than those with other threemethods; meanwhile, all RMSEs decrease by more than5.170.3. Through analyzing original non-pesticide spectrogram of trichlorphon for surface of appleand non-pesticide spectrogram for surface of pear, this paper has concluded that: thecharacteristic displacement of trichlorphon Raman spectrum generally lies within100~1800cm-1and2700~3200cm-1; the characteristic peaks are relatively abundant and points including279,296,444,623,789,2863and2956cm-1are selected as characteristic displacement signals fortrichlorphon detection; characteristic displacement of Roman spectrum of non-residue applesurface is generally presented in:1411,1536,1611,2848and2932cm-1; characteristicdisplacement of Roman spectrum of non-residue pear surface is generally presented in:1056,1124,1288,1430,1646,2842and2876cm-1.4. According to different-concentration trichlorphon Roman spectrum analysis of apple andpear, the residues of trichlorphon on surface of the apple is480mg/Kg and48mg/Kg. Origin9.0software is applied for establishing mathematic models between peak intensity of Ramanspectrum and concentration of trichlorphon and between peak area and concentration oftrichlorphon, both of which conform to the linear relationship: y ax b. In the regressionmodel established with peak intensity for apple, the average value of coefficient R is0.981and0.982. In the regression model established with area method, the average value of coefficient R is0.981and0.988, which means average value of correlation coefficient of regression modelestablished with peak area is0.006higher than that of regression model established with peakintensity. To sum up, regression model established with peak area is superior to that establishedwith peak intensity.