Application of FTIR combined with chemometric technique for the identification of Khat and its similar plants
Objective To distinguish Khat from its similar plants,such as white tea and Houttuynia cordata,so as to identity Khat and its camouflage and confusing products in smuggling crime and public security anti-drug work.Methods FTIR is used to collect the infrared spectral data of plant samples,and the data are analyzed by chemometrics.The original data were preprocessed by three data processing methods,namely,SG smoothing,baseline and normalization,then the processed data were classified and reduced by PCA,finally the mathematical model was constructed by three methods:KNN,RF and SVM for classification and prediction.Results The results were expressed by confusion matrix,and the accuracy of the RF model is 96.51%.The accuracy of the SVM model is 98.84%;The accuracy of the KNN model is 93.02%.Conclusion In this experiment,FTIR was used to establish a model for rapid identification of Khat grass,the SVM model has the highest correct recognition rate and good parameters,which can be used to distinguish dry khat from its similar plants.