基于表面增强拉曼光谱技术的苹果汁中溴氰菊酯农药残留的快速定量分析
Quantitative Analysis of Deltamethrin Pesticide Residues in Apple Juice Based on Surface Enhanced Raman Scattering
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摘要: 针对苹果汁中农药残留量超标问题,采用共焦显微拉曼仪,研究了针对苹果汁中溴氰菊酯农残量的快速检测方法。分别以乙醇溶液(对照)、苹果汁溶液为背景溶液,分别采用拉曼光谱技术、表面增强拉曼光谱技术(SurfaceEnhanced Raman Scattering,SERS)采集含农药(溴氰菊酯)的两种样本的拉曼光谱与SERS光谱,并结合一阶导加Norris求导法进行光谱预处理,进而使用偏最小二乘方法建立两种样本溶液中溴氰菊酯残留量的拉曼光谱定量分析模型与SERS光谱定量分析模型,并对两种模型进行对比分析。结果表明,乙醇中溴氰菊酯溶液样本的拉曼光谱定量分析模型的校正集相关系数可达到0.9634,而SERS模型校正集相关系数可达到0.9995,最大误差不超过0.1 mg/kg。苹果汁中溴氰菊酯样本的拉曼光谱模型校正集相关系数为0.9355,最大误差不超过0.02 mg/kg;而SERS模型校正集相关系数为0.9870,最大误差不超过0.1 mg/kg。结果表明,拉曼光谱技术对快速检测苹果汁中的农药残留量具有可行性。Abstract: To solve the problem of pesticide residues in apple juice exceeding the standard, a confocal microscopic Raman spectrometer was used to study the rapid determination of deltamethrin residues in apple juice.Using ethanol solution (control) and apple juice as background solution, the Raman spectra and Surface Enhanced Raman Scattering (SERS) spectra of samples containing pesticides (deltamethrin) were collected by Raman scattering and SERS, respectively.Then, the first-order derivative and Norris derivative method was employed to preprocess the spectra, and the partial least squares method was used to establish the quantitative analysis model of the deltamethrin residues in the two background solution.The results showed that correlation coefficient of the calibration set of the Raman spectra quantitative analysis model in ethanol solution could reach 0.9634, while the correlation coefficient of the model calibration set model which adopted the SERS method could reach 0.9995.The maximum error was within 0.1 mg/kg.The results showed that the correlation coefficient of Raman spectra of deltamethrin sample in apple juice was 0.9355, and the maximum error was within 0.2 mg/kg.The correlation coefficient of the model calibration set of the SERS method was 0.9870, and the maximum error was within 0.1 mg/kg. The results showed that Raman spectroscopy was feasible for rapid detection of pesticide residues in apple juice.