Rapid determination of four tobacco specific nitrosamines in burley tobacco by near-infrared spectroscopy

Abstract

Indirect modeling of trace components in real samples by use of near-infrared spectroscopy (NIRS) has gained much interest, because it may provide a rapid way for analyzing the industrial or agricultural products. Coupling near-infrared diffusive reflectance spectroscopy and chemometric techniques, a method for rapid analysis of four tobacco specific N-nitrosamines (TSNAs) and their total content is studied in this work. For optimization of the models, techniques for spectral preprocessing and variable selection are adopted and compared. It is found that to remove the varying background and correction of the multiplicative scattering effect in the spectra is important in modeling, also variable selection can significantly improve the models. For validation of the models, the TSNA contents of independent test samples and tobacco leaves harvested in different years were predicted. Consistent results were obtained between the reference contents by GC/TEA analysis and those predicted. Although the relative errors for some low content samples are not satisfactory, the method is a practical alternative for industrial analysis due to the non-destructive and rapid nature of the method.