Fluorescence spectroscopy detection of carbendazim residue in cucumber juice based on BC

Excessive residues of the carbendazim pesticide in food will cause food safety issues. Particularly, cucumber is one of the common vegetables with carbendazim residues. This study, using fluorescence spectroscopy technology, explored the residues of carbendazim in cucumbers. First, a fluorescence spectrophotometer was used to scan and obtain the three-dimensional fluorescence spectra of carbendazim standard and four carbendazim formulations. Analyzing and comparing their respective fluorescence characteristics, fluorescence peak 1: Ex/Em=245/300~320 nm and fluorescence peak 2: Ex/Em=280/300~320 nm have been identified as the fluorescence characteristic peaks of carbendazim, and the optimal excitation wavelengths Ex=245 nm and Ex=280 nm with carbendazim specificity was screened. Subsequently, two-dimensional fluorescence spectroscopy was performed on the carbendazim and cucumber-carbendazim mixed solutions using the optimal excitation wavelength. In order to obtain more effective two-dimensional spectral data, the original fluorescence spectrum of the cucumber-carbendazim mixed solution was subjected to Blank Correction (BC), significantly reducing the impact of cucumber's own fluorescent characteristics on the carbendazim fluorescent peak in the mixed solution. Polynomial models and linear prediction models were developed based on the concentration of carbendazim and the fluorescence peak intensity values obtained after BC. The detection limit value of carbendazim residues in the cucumber-carbendazim mixed system included the maximum pesticide residue limit specified by national food safety regulations. This research provides valuable data and technical support for efficient detection of pesticide residues in cucumbers.