Importance of Semivolatile/Intermediate-Volatility Organic Compounds to Secondary Organic Aerosol Formation from Chinese Domestic Cooking Emissions

Abstract

Here, we deploy a Gothenburg potential aerosol mass reactor (Go:PAM) to investigate the secondary organic aerosol (SOA) formation from Chinese domestic cooking emissions. Volatile organic compounds (VOCs) and semivolatile/intermediate-volatility organic compounds (S/IVOCs) were measured by a Vocus proton transfer reaction time-of-flight mass spectrometer (Vocus PTR-TOF). SOA mass was calculated by particle number size distribution and the particle density that was measured by a centrifugal particle mass analyzer. The primary organic aerosols (POA) emission rates are 2.0, 2.2, 1.8, and 1.1 mg min–1 for chicken, tofu, cabbage, and Kung Pao chicken, respectively. Correspondingly, the SOA production rates are 2.7, 2.4, 2.3, and 1.9 mg min–1. Our results show the distinct precursors and SOA formation from real-world cooking emissions compared with cooking oil heating emissions. The cooking style has a greater impact on the primary emissions and SOA formation than the cooking material. A closure study shows that the VOCs oxidation can only explain 5%–23% of measured SOA. This percentage increases to 19%–55% when considering S/IVOCs oxidation. Our study demonstrates the importance of S/IVOCs oxidation to SOA formation from cooking emissions, suggesting an urgent need for comprehensive S/IVOCs characterization from cooking emissions.