Study on Detection of Pesticide Residues on Winter Jujube Surface by Near-infrared Spectroscopy Combined with PLS and SPA

摘要

cqvip:With fresh winter jujube from the southern region of Xinjiang as the object of study,the method for detecting pesticide residues on winter jujube surface by near-infrared spectroscopy( NIR) combined with successive projections algorithm( SPA) and partial least squares( PLS) was investigated. The absorbance information of winter jujube sample surface was obtained through NIR technology,for the building of a full-wave band PLS model of fresh winter jujube sample sprayed with different concentrations of pesticide( taking chlorpyrifos as an example) as well as an SPA-PLS model which was built with the characteristic wavelengths extracted with SPA as the input variables for PLS,and the prediction precision of the two kinds of models was compared. The model built with the five characteristic waveslengths extected by SPA method only used the variables 0. 32% of all the variables in the full wave band,but its accuracy and precision were better than the model built with the full wave band. It is feasible to build a model for different concentrations of chlorpyrifos on fresh winter jujube surfarce by NIR technology combined with SPA and PLS,and SPA method could simplify the complexity of the model and improve the precision and stablity of the model.