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Trace analysis of alkaline flavors in cut tobacco by heart-cutting multidimensional GC-GC-MS.

Tobacco is a complex chemical matrix. The analysis of trace alkaline flavors in tobacco is very difficult because of the limited peak capacity of monodimensional GC. In the present study, a home-assembled twin-oven GC-GC-MS system, with MS detection in both dimensions, has been applied to the analysis of 20 alkaline volatiles in a variety of cut-tobacco samples. By transferring nine and six heart-cuts from the first apolar column to the second polar column in two separate runs, the potential mutual interference of adjacent isomeric targets and the complex matrix could be removed. For comparative purposes, a systematic comparison of both quantification and qualification results for the cut-tobacco sample as quality control was conducted between GC-GC-MS and GC-MS. The results showed that GC-GC-MS provided higher accuracy in peak assignment and quantification. And in GC-MS, the interferences of co-elution had caused both low matched similarity in peak assignment and false-negative/-positive results in quantification for some targets. Advantages of the developed GC-GC-MS method in the analysis of alkaline flavors are its high resolving power, reliability, and simplicity.