基于拉曼光谱技术检测菠菜毒死蜱残留的初步研究

Detection method of chlorpyrifos pesticide residue on spinach surface based on Raman spectroscopy

中文关键词:  菠菜  毒死蜱  拉曼光谱  快速  无损

英文关键词:spinach  chlorpyrifos  Raman spectrum  rapid  non-destructive

中文摘要:

      目的 基于拉曼光谱技术初步探讨菠菜表面有机磷农药毒死蜱的快速、无损检测新方法。方法 利用本研究自行搭建的拉曼光谱检测系统获取残留不同浓度毒死蜱农药的菠菜光谱曲线, 通过SG-5点平滑减小曲线噪声, 基于最小二乘法的10次多项式拟合法剔除菠菜荧光背景, 并对含有不同浓度毒死蜱农药的菠菜样品拉曼图谱进行比较分析。结果 特征归属为P=S振动的632 cm-1处的拉曼信号可识别菠菜表面毒死蜱农药残留, 其检测限为400 mg/kg, 而且拉曼特征波峰的相对强度与菠菜表面农药残留浓度存在较好的线性关系, 其相关系数为R2=0.92。结论 拉曼光谱技术有望实现叶片类蔬菜的农药残留的快速、无损、定量检测。

英文摘要:

      Objective To explore a rapid and nondestructive method for the determination of pesticide residue on the surface of spinach by Raman spectroscopy. Methods Raman spectral signals from different con-centrations of pesticide on spinach were acquired by laboratory-setting-up Raman spectroscopy detection system. Savitzky-Golay five-point filter was used to smooth the original Raman spectra, the 10th order polynomial fitting based on the partial least square was used to remove the fluorescence background from Raman signals, and compared the Raman spectrum of spinach containing different concentration chlorpyrifos pesticide. Results Chlorpyrifos pesticide residue on spinach surface could be detected based on 632 cm-1 Raman signal (chemical bonds vibration of P=S), the minimum value of chlorpyrifos pesticide on spinach surface was 400 mg/kg, and there was a good linear correlation between the concentrations of pesticide residue on spinach’s surface and the relative intensity of Raman signals. The correlation coefficient of this study was 0.92. Conclusion The study demonstrated that Raman spectroscopy had a great potential for rapid and non-destructive detection of pesticide residue on spinach’s surface.