Integrated GC × GC-FID method for high-efficiency gasoline analysis: From standard quantification to non-target screening.

Conventional one-dimensional gas chromatography methods for gasoline quality monitoring require separate analyses for different component classes, limiting analytical efficiency and unconventional additive detection. This study presents a comprehensive two-dimensional gas chromatography with flame ionization detection (GC × GC-FID) platform enabling simultaneous quantification of regulated components and rapid screening of unconventional additives in a single analytical run. The method achieved excellent agreement with ASTM standards and high repeatability for BTEX (benzene, toluene, ethylbenzene, and xylenes) and oxygenates in gasoline. Multi-laboratory validation further confirmed its robust cross-platform stability, with recoveries of 86.9 %-103.8 % and most inter-laboratory relative standard deviations (RSDs) below 3 %. A GC × GC fingerprinting strategy based on chemical class clustering successfully identified trace unconventional additives, including polyoxymethylene dimethyl ether (DMM₂) and methyl acetate, which were missed by conventional approaches. This integrated solution addresses critical gaps in current regulatory frameworks while providing enhanced detection capabilities and robust transferability for comprehensive fuel quality monitoring.