Going Greener and Smarter in GC×GC: FID–MS Chromatogram Fusion for Fragrance Allergen Analysis

Comprehensive two-dimensional gas chromatography (GC×GC) with parallel flame ionization detection (FID) and mass spectrometry (MS) represents a powerful approach for the detailed characterization of volatile and semi-volatile compounds in complex matrices. The complementary nature of the two detectors combines the extended linear dynamic range and robustness of FID for accurate quantification with the selectivity and structural information provided by MS for reliable compound identification and resolution of co-elutions. These features are particularly relevant for the determination of fragrance allergens, where reliable identification and robust quantification are required to comply with regulatory requirements. Conventional GC×GC–FID/MS workflows require independent processing of detector signals, resulting in time-consuming data handling and increased operator intervention. In this contribution, an integrated data-processing workflow developed on the GC Image software platform is presented, enabling the fusion of GC×GC FID and MS chromatograms into a single one. The fused chromatogram preserves the quantitative reliability of FID while incorporating MS-based spectral matching for confident identification, improving template matching and enabling large-scale quantitative allergen profiling. The approach addresses key challenges associated with dual parallel detection, including differences in acquisition frequency between detectors and instrumental configurations based on thermal or differential-flow modulation. From a methodological perspective, this work extends chromatogram-level GC×GC data fusion to hydrogen carrier gas conditions, representing a novel step toward sustainable and efficient allergen analysis. The use of a HydroInert ion source enables reliable MS detection under hydrogen operation while preserving quantitative robustness and identification confidence comparable to helium-based methods. The integration of chromatogram fusion with hydrogen operation enables GC×GC–FID/MS workflows that are simultaneously greener and smarter, reducing helium consumption and analysis time while supporting automated and information-rich fragrance allergen analysis.