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The gas-phase reactions of ozone with alkenes can be significant sources of free radicals (OH, HO(2) and RO(2)) in the Earth's atmosphere. In this study the total radical production and degradation products from ethene ozonolysis have been measured, under conditions relevant to the troposphere, during a series of detailed simulation chamber experiments.(More)
The gas-phase reaction of ozone with unsaturated volatile organic compounds (VOCs), alkenes, is an important source of the critical atmospheric oxidant OH, especially at night when other photolytic radical initiation routes cannot occur. Alkene ozonolysis is also known to directly form HO2 radicals, which may be readily converted to OH through reaction with(More)
The technique of proton transfer reaction mass spectrometry (PTR-MS) couples a proton transfer reagent, usually H3O+, with a drift tube and mass spectrometer to determine concentrations of volatile organic compounds. Here we describe a first attempt to use chemical ionization (CI) reagents other than proton transfer species inside a PTR-MS instrument. The(More)
The performance of a new chemical ionization reaction time-of-flight mass spectrometer (CIR-TOF-MS) util-ising the environment chamber SAPHIR (Simulation of Atmospheric Photochemistry In a large Reaction Chamber-Forschungzentrum Jülich, Germany) is described. The work took place as part of the ACCENT (Atmospheric Composition and Change the European NeTwork(More)
A series of photooxidation experiments were conducted in an atmospheric simulation chamber in order to investigate the secondary organic aerosol (SOA) formed from the anthropogenic model gas phase precursor, 1,3,5-trimethylbenzene. Alongside specific aerosol measurements, comprehensive gas phase measurements, primarily by chem-5 ical ionisation reaction(More)
The use of β-caryophyllene secondary organic aerosol particles as seeds for smog chamber simulations has been investigated. A series of experiments were carried out in the Manchester photochemical chamber as part of the Aerosol Coupling in the Earth System (ACES) project to study the effect of seed particles on the formation of secondary organic aerosol(More)
The effect of photochemical ageing and initial precursor concentration on the composition and hygroscopic properties of secondary organic aerosol (SOA) formed during the chamber photo-oxidation of β-caryophyllene/NO x mixtures were investigated. Nucleation of β-caryophyllene SOA particles occurred almost immediately after oxidation was initiated and led to(More)
Secondary organic aerosol (SOA) is well-known to have adverse effects on air quality and human health. However, the dynamic mechanisms occurring during SOA formation and evolution are poorly understood. The time-resolved SOA composition formed during the photo-oxidation of three aromatic compounds, methyl chavicol, toluene and 4-methyl catechol, were(More)
A degradation mechanism for β-caryophyllene has recently been released as part of version 3.2 of the Master Chemical Mechanism (MCM v3.2), describing the gas phase oxidation initiated by reaction with ozone, OH radicals and NO3 radicals. A detailed overview of the construction methodology is given, within the context of reported experimental and theoretical(More)
The performance of a new chemical ionization reaction time-of-flight mass spectrometer (CIR-TOF-MS) utilising the environment chamber SAPHIR (Simulation of Atmospheric Photochemistry In a large Reaction Chamber – Forschungzentrum J ¨ ulich, Ger-many) is described. The work took place as part of the ACCENT (Atmospheric Com-5 position and Change the European(More)