Miniaturized multi-analytical characterization of aliphatic amines, dicarbonyls, and PAHs in PM2.5via low-mass filter aliquots: analytical workflow and environmental application.

This work presents a downscaled and resource-efficient multi-analytical workflow for the parallel determination of polar indicators (aliphatic amines, short-chain dicarbonyls, malondialdehyde) and combustion tracers (PAHs) using micro-aliquots of PM2.5 filters (0.07 g, equivalent to ∼60 m3 of sampled air). By implementing dedicated chemical derivatization protocols (Fmoc-Cl for amines and acid-catalyzed DNPH for dicarbonyls) alongside direct solvent extraction for PAHs, the method minimizes sample consumption and solvent waste while achieving limits of detection in the low pg m-3 to ng m-3 range. Procedural optimization ensured robust intermediate precision (<12% RSD across target analytes) and controlled reagent hydrolysis artifacts. The analytical performance was validated through a three-day field study during a sharp meteorological transition, demonstrating that the downscaled strategy effectively resolves short-term diurnal shifts and local chemical transformations from minimal sample mass without requiring full-filter destruction.