Extraction and identification of mixed pesticides' Raman signal and establishment of their prediction models

Abstract

A nondestructive and sensitive method is developed to determine mixed pesticides of acetamiprid, chlorpyrifos and carbendazim in apple samples by surface‐enhanced Raman spectroscopy (SERS). Self‐modeling mixture analysis (SMA) was used to identify and extract the Raman signals of each pesticide from the spectra of apples contaminated with mixed pesticides. Results indicate that the obtained SERS signal intensities of each pesticide in their mixture have no obvious difference to the signal intensities of the corresponding pure pesticide at a low concentration. The lowest detectable level of acetamiprid, chlorpyrifos and carbendazim in apple are 0.0054 mg/kg, 0.064 mg/kg and 0.014 mg/kg, respectively, which are sensitive enough for identifying apple contaminated with pesticides above the maximum residue limit. The predicted values of each pesticide in their mixture are obtained using the prediction model based on the Raman signal of the single pesticide. The correlation coefficients of predicted values and actual values are 0.893 for acetamiprid, 0.926 for chlorpyrifos and 0.938 for carbendazim, respectively. The method presents the ultrasensitive SERS performance for quantifying residual pesticides in apple samples without sample pre‐treatment, showing great potential to serve as a useful means for monitoring pesticide residues used in mixed state. Copyright © 2016 John Wiley & Sons, Ltd.

A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk

“…Surface-enhanced Raman spectroscopy (SERS) uses metals such as gold (Au) or silver (Ag) in colloidal form to enhance Raman signal intensity, greatly lowering detection limits. SERS has been widely used in food authentication research for detection of microorganisms and contaminants [ 35 , 36 , 37 , 38 , 39 , 40 ] and for detection of antibiotics in biomedical and pharmaceutical applications [ 41 , 42 ]. SERS has been applied to qualitatively detect antibiotics in aqueous solutions, demonstrating its potential for food safety applications [ 43 , 44 ].…”

Ag and Au nanostructures for surface‐enhanced Raman spectroscopy of Mospilan 20 SP (acetamiprid)

“…Some of the bands of the acetamiprid (Mospilan 20 SP) were summarized in Table 2 where those described in previous works [27][28][29][30][31][32][33] are also presented for comparison. It is worth noting that the bands presented by Chen [27] relayed for the pure acetamiprid powder.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XII

“…Zhai et al studied the extraction and identification of the Raman spectral signatures of mixed pesticides and worked on the establishment of corresponding prediction models. They concluded that their method displays an ultrasensitive level of SERS performance for quantifying residual pesticides in apple samples without sample pretreatment, thereby showing great potential to serve as a useful means for monitoring mixtures of pesticide residues …”

“…They concluded that their method displays an ultrasensitive level of SERS performance for quantifying residual pesticides in apple samples without sample pretreatment, thereby showing great potential to serve as a useful means for monitoring mixtures of pesticide residues. [45] 9.4 | Tip-enhanced Raman spectroscopy Hoffmann et al used tip-enhanced Raman to map singlewalled carbon nanotube networks (SWCNTs) in conductive composite materials. Using TERS, the surface of a polymer-embedded conductive network of SWCNTs was mapped underneath a thin layer of pure polymer.…”