Fourier Deconvolution Multiplexing Boosts Ion Throughput in Pinhole-Interfaced GC-IMS/MS for Synchronous Peak Identification

Gas chromatography-ion mobility spectrometry has been recognized as a rapid, sensitive, portable approach at low cost in food safety analysis, environmental monitoring, and security screening. However, the peak identification remains a major challenge due to the lack of sufficiently comprehensive reference databases. This study successfully developed and validated an integrated gas chromatography-ion mobility spectrometry/mass spectrometry (GC-IMS/MS) platform incorporating Fourier deconvolution (FD) technology and a pinhole IMS-MS interface, aiming to resolve the limitations of low ion utilization efficiency and detector sensitivity imbalance in conventional GC-IMS/MS systems. The implementation of FD multiplexing increased the ion gate duty cycle from <0.4% in conventional beam chopping ion gates to 50%, while a unique interface design substantially enhanced ion transmission efficiency to the mass spectrometer. Experimental results confirmed precise synchronization between IMS drift peaks and MS spectral data for six target volatile organic compounds (ethyl caproate, methyl heptenone, linalool, citronellyl acetate, l (-)-carvone, and nerol) at identical retention times, with an average ion transmission enhancement exceeding 110-fold. The platform also demonstrated satisfactory quantitative performance, with all target compounds exhibiting linearity (R² > 0.995) across concentration ranges spanning 3 orders of magnitude and achieving detection limits at the ng/mL level. Three complex extracts including tobacco, Da Hong Pao tea, and apricot flavoring were investigated to evaluate the performance of the developed system, and it was demonstrated that the developed system exhibited precise compound identification and high-throughput nontargeted screening capabilities.