Non-target scanning of organics from cooking emissions using comprehensive two-dimensional gas chromatography-mass spectrometer (GC×GC-MS)

Abstract

Cooking emission is a major source influencing human health and air quality. To elucidate the emission pattern of cooking fumes, gaseous and particulate organics were sampled by Tenax TA desorption tubes and quartz filters, respectively. Organics were analyzed by a comprehensive two-dimensional gas chromatography-quadrupole mass spectrometer (GC × GC-qMS) coupled with a thermal desorption system (TDS). A non-target analysis was conducted identifying 166 (gas-phase) and 349 (particle-phase) compounds emitted from cooking fumes. We propose a four-step identification procedure, containing comparison with standards, homologs identification by selected ion chromatograms (SICs), searching spectrums in the National Institute of Standard Technology (NIST) library, and recognitions of unresolved complex mixtures (UCMs). The identified organics are then quantified or semi-quantified by surrogates in the same chemical class with an uncertainty of 27%. Intermediate volatility organic compounds (IVOCs) are extensively detected accounting for 20.5% and 81.4% of the total mass concentration and emission rates (ERs) in gas- and particle-phase samples. Aldehydes (30.6%) and acids (82.7%) dominate the mass concentration of organics in the gas- and particle-phase, respectively. Our work provides a detailed identification procedure in the non-target analysis and emphasizes the importance of IVOC measurement in cooking emissions.