Abstract: The volatile and semivolatile components in burley tobacco leaves were analyzed by headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS). Twenty milligrams of tobacco powder was incubated at 60 ℃ for 8 min and then extracted using 65 μm polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber for 40 min. Finally, the fiber was desorbed at 250 ℃ for 3 min. One hundred twenty two kinds of volatile and semivolatile components in the burley tobacco leaves were tentatively identified by comparing with standard products and mass spectrometry databases, and these compounds were semi-quantitatively analyzed by the internal standard method. The differences between the volatile and semivolatile components for the burley tobacco leaves before and after baking were discriminated and visualized by principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). This method has the advantages of small sample size, simple pretreatment, and high sensitivity. In combination with chemometrics, the HS-SPME-GC/MS method is suitable for discriminating changes in the chemical composition of burley tobacco before and after baking, and hence has broad prospective application in the optimization of the baking conditions used for burley tobacco.

Key words: headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS), principle component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), volatile components, semivolatile components, burley tobacco