Measurement of Volatile Organic Compounds (VOCs)
Project:
Measurement of Volatile Organic Compounds (VOCs) by Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)
Principal Investigators:
Jonathan Abbatt (jabbatt@chem.utoronto.ca)
Steve Sjostedt, University of Toronto (ssjosted@chem.utoronto.ca)
Department of Chemistry
University of Toronto
80 St. George St.
Toronto, ON M5S 3H6
Canada
Objectives:
- To assess the degree of local photochemical activity versus long-range transport, as assessed through measurements of both short-lived and longer-lived oxygenates such as formaldehyde and acetone, respectively.
- To measure signatures for biogenic release of dimethyl sulfide and relate to measurements of new particle formation at the site
- To look for halogenated VOCs that may be tracers for the occurrence of halogen activation
- To assess the degree of local or regional pollution from measurements of species such as benzene and toluene
- To provide an opportunity for intercomparison with other measurement techniques, such as formaldehyde
- To contrast similar measurements made by the same PTR-MS unit in the Canadian Arctic in the summer/fall of 2007-2008 as part of the Canadian Arctic-SOLAS project.
Measurement Technique:
The instrument to be deployed is the commercial Ionicon Analytik low-mass-resolution Proton-Transfer-Reaction Mass Spectrometer. The measurement technique employs the protonation of VOCs by the H3O+ ion, followed by subsequent mass selection with a quadrupole mass spectrometer. Species with proton affinities greater than water are detected, frequently as a protonated molecular ion but ionic fragmentation can also occur.