Hydrogen Carrier Gas Method Translation in Comprehensive Two-Dimensional Gas Chromatography for Sustainable Nontargeted Analysis.

The selection and control of carrier gas are critical factors influencing the performance of both one-dimensional gas chromatography (1D GC) and comprehensive two-dimensional gas chromatography (GC×GC). Helium is widely used due to its inertness, but increasing cost, limited supply, and reliance on fossil fuel extraction raise sustainability concerns. Hydrogen offers a viable alternative, with faster optimal linear velocity to reach comparable efficiency, and more sustainable production through generators relying on water electrolysis. While tools exist to translate 1D GC methods from helium to hydrogen, their application to GC×GC has not been well established, particularly for parameters unique to multidimensional separations. This work presents the translation of helium to hydrogen carrier gas for cryogenically modulated GC×GC-MS. Three translated methods derived from 1D tools were evaluated alongside modulation period using standard mixtures, followed by validation with authentic fingermark residue samples in a forensic application. The translate option, using a combination of flow and temperature adjustments that matched column efficiency between helium and hydrogen, delivered comparable peak capacity, as well as acceptable S/N, tailing factors, and resolution values between key peak pairs. Modulation period could be reduced by 50%, providing a practical guideline for method translation. Hydrogen reduced overall run time by up to 60%, increasing sample throughput and lowering per-sample energy consumption. Although sustainability comparisons are nuanced, hydrogen showed improved green chemistry alignment overall, supported by higher sustainability metric scores and gains in efficiency and resource use.