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采用柠檬酸钠还原法合成纳米金颗粒溶胶,利用表面增强拉曼光谱技术(SERS)结合化学计量学,对烯啶虫胺、噻虫嗪和吡虫啉3种农药进行研究,建立了3种农药的拉曼光谱研究方法。采集农药溶液的拉曼光谱曲线,运用自主编写的程序对光谱曲线进行预处理,去除光谱噪音、基线漂移和荧光背景的干扰。结果表明,合成的纳米金颗粒溶胶对3种农药具有良好的增强效果,在拉曼特征频率400~1500 cm~(-1)范围内较为丰富;755,846和1109,633,771,994和1074 cm~(-1)以及995,1109和1034 cm~(-1)可分别用于识别烯啶虫胺,噻虫嗪和吡虫啉。烯啶虫胺、噻虫嗪和吡虫啉检测限分别为0.05,0.025,0.025 mg/L;并对特征峰1109,633,995 cm~(-1)进行线性拟合,R~2均大于0.93。对进一步实现表面增强拉曼光谱技术检测农产品复杂基质中新烟碱农药具有重要意义。
Nano gold particles sol was synthesized by sodium citrate reduction method. Three kinds of pesticides, nitenpyram, thiamethoxam and imidacloprid, were studied by surface enhanced Raman spectroscopy (SERS) and chemometrics. Three pesticides Raman spectroscopy methods. The Raman spectra of the pesticide solution were collected and the spectra were preprocessed using a self-written program to remove spectral noise, baseline drift, and fluorescence background interference. The results showed that the synthesized gold nanoparticles sol had good enhancement effect on three kinds of pesticides, and was abundant in Raman characteristic frequencies of 400 ~ 1500 cm -1; while 755,846 and 1109,633,771,994 and 1074 cm -1 ) And 995, 1109 and 1034 cm -1 could be used to identify nitenpyram, thiamethoxam and imidacloprid, respectively. The detection limits of nitenpyram, thiamethoxam and imidacloprid were 0.05, 0.025 and 0.025 mg / L, respectively. The characteristic peaks of 1109, 633 and 995 cm -1 were linearly fitted with R 2 values greater than 0.93. It is of great significance to further realize surface enhanced Raman spectroscopy in the detection of neonicotinoid pesticides in complex matrices.