Studying Interfacial Dark Reactions of Glyoxal and Hydrogen Peroxide Using Vacuum Ultraviolet Single Photon Ionization Mass Spectrometry

摘要: Aqueous secondary organic aerosol (aqSOA) formation from volatile and semivolatile compounds at the air–liquid interface is considered as an important source of fine particles in atmosphere. However, due to lack situ detecting techniques, detailed interfacial reaction mechanism dynamics still remain uncertain. In this study, synchrotron-based vacuum ultraviolet single-photon ionization mass spectrometry (VUV SPI-MS) was coupled with System for Analysis Liquid Vacuum Interface (SALVI) investigate glyoxal dark oxidation products aqueous surface. Mass spectral analysis determination appearance energies (AEs) suggest that main aging are carboxylic acid related oligomers. Furthermore, VUV SPI-MS results were compared validated against those liquid time-of-flight ion (ToF-SIMS). The mechanisms oxidation, obtained using two different approaches, indicate differences instrument operation principles could contribute their abilities detect Therefore, mechanistic revealed between ToF-SIMS more real-time techniques needed contribution reactions leading aqSOA formation.