Chlorine-initiated oxidation of n-alkanes under high-NO x conditions: insights into secondary organic aerosol composition and volatility using a FIGAERO–CIMS

Wang, Dongyu S.; Hildebrandt Ruiz, Lea

Chlorine-initiated oxidation of inline-formulan-alkanes (inline-formulaC8−12) under high-nitrogen oxide conditions was investigated. Observed secondary organic aerosol yields (0.16 to 1.65) are higher than those for OH-initiated oxidation of inline-formulaC8−12 alkanes (0.04 to 0.35). A high-resolution time-of-flight chemical ionization mass spectrometer coupled to a Filter Inlet for Gases and AEROsols (FIGAERO–CIMS) was used to characterize the gas- and particle-phase molecular composition. Chlorinated organics were observed, which likely originated from chlorine addition to the double bond present on the heterogeneously produced dihydrofurans. A two-dimensional thermogram representation was developed to visualize the composition and relative volatility of organic aerosol components using unit-mass resolution data. Evidence of oligomer formation and thermal decomposition was observed. Aerosol yield and oligomer formation were suppressed under humid conditions (35 % to 67 % RH) relative to dry conditions (under 5 % RH). The temperature at peak desorption signal, inline-formulaTmax, a proxy for aerosol volatility, was shown to change with aerosol filter loading, which should be constrained when evaluating aerosol volatilities using the FIGAERO–CIMS. Results suggest that long-chain anthropogenic alkanes could contribute significantly to ambient aerosol loading over their atmospheric lifetime.



Wang, Dongyu S. / Hildebrandt Ruiz, Lea: Chlorine-initiated oxidation of n-alkanes under high-NOx conditions: insights into secondary organic aerosol composition and volatility using a FIGAERO–CIMS. 2018. Copernicus Publications.


12 Monate:

Grafik öffnen


Rechteinhaber: Dongyu S. Wang

Nutzung und Vervielfältigung: