Comparison of the applications of GC-IMS and SPME-GC-MS in the analysis of volatile flavor compounds in strong-flavor Baijiu

In order to compare the application differences of solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS) techniques in the detection of flavor compounds in strong-flavor (Nongxiangxing) Baijiu, the volatile flavor compounds of 10 representative strong-flavor Baijiu samples were detected by both techniques. The method consistency was evaluated by Pearson correlation coefficient and significant level, and the samples from different regions were distinguished through principal coordinate analysis (PCoA). The results showed that a total of 95 volatile flavor substances were detected by the two methods. Among them, 59 compounds were detected by SPME-GC-MS, and 47 compounds were detected by GC-IMS. The common core components detected by the both methods were 11. Both methods might have certain limitations in detecting polar or small molecule compounds. SPME-GC-MS had higher sensitivity for non-polar long-chain esters and benzene-containing compounds, while GC-IMS had a rapid response ability for low-boiling polar compounds. Moreover, it was found that there were technical selection differences in the clustering results of some samples through PCoA. The research results indicated that SPME-GC-MS and GC-IMS techniques had complementarity in the detection of flavor components in strong-flavor Baijiu.