Acta Optica Sinica, Volume. 39, Issue 7, 0730001(2019)
Fast Detection of Chlorpyrifos Residues in Tea via Surface-Enhanced Raman Spectroscopy Combined with Two-Dimensional Correlation Spectroscopy
In this study, surface-enhanced Raman spectroscopy (SERS) combined with two-dimensional correlation spectroscopy is used to develop a quantitative analysis model for rapidly detecting chlorpyrifos pesticide residues in tea. First, using gold colloid as the enhanced substrate, the spectral data of chlorpyrifos residues in tea samples with different concentrations are collected via SERS. Then, the original Raman spectra are pretreated using standard normal variate transformation (SNV). The chlorpyrifos concentration is considered as the disturbance and the characteristic peaks of chlorpyrifos are screened out via two-dimensional correlation synchronous spectrum and autocorrelation spectrum analysis. Parameters of the support vector machine (SVM) algorithm are optimized using the gray wolf algorithm (GWO), and the optimized SVM model is used for analyzing the chlorpyrifos residues in tea. The performance of optimized SVM model is compared to that of the model based on partial least squares (PLS). Results show that 14 chlorpyrifos characteristic peaks are screened using the two-dimensional correlation spectroscopy and the determination coefficient ( Rp2) of the proposed SVM model in the prediction set is 0.98, the root mean square error of prediction (RMSEP) is 1.32, and the relative prediction deviation (RPD) is 6.32. These values indicate that the developed model can be used for the actual estimation of chlorpyrifos pesticide residues in tea and performs better than the SVM model based on the 1096-cm 1 feature peak and PLS model. Thus, two-dimensional correlation spectroscopy is suitable for screening characteristic peaks related to chlorpyrifos concentrations in tea. This finding leads to a new idea for optimizing the characteristic variables in Raman spectroscopy. Results also show that SERS combined with two-dimensional correlation spectroscopy can rapidly and accurately detect chlorpyrifos pesticide residues in tea. The proposed method will provide methodological support for the development of rapid detection devices for analyzing pesticide residues in tea.
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Xiao Hu, Ruimei Wu, Xiaoyu Zhu, Peng Liu, Aihua Xiong, Junshi Huang, Puxiang Yang, Junfei Xiong, Shirong Ai. Fast Detection of Chlorpyrifos Residues in Tea via Surface-Enhanced Raman Spectroscopy Combined with Two-Dimensional Correlation Spectroscopy[J]. Acta Optica Sinica, 2019, 39(7): 0730001
Category: Spectroscopy
Received: Jan. 28, 2019
Accepted: Mar. 28, 2019
Published Online: Jul. 16, 2019
The Author Email: Ai Shirong (aisrong@163.com)