Speciated Measurements of VOCs in New York City by an In Situ GC-TOF-MS for the Characterization of Primary Emissions in Urban Air

VOCs are emitted into the atmosphere from an array of anthropogenic and biogenic (natural) sources, including combustion from industry and transportation, oil and natural gas, biomass burning, vegetation, and the use of VCPs. Once VOCs enter the atmosphere, they may undergo subsequent reactions that alter the oxidative capacity of the atmosphere through the formation of tropospheric ozone and secondary organic aerosols (SOA). In urban areas, there has been a paradigm shift in the relative importance of VOC emissions from transportation sources to non-combustion sources like VCPs. Very little is known about these urban VOCs, including source apportionment, temporal behavior, and relative importance to ozone and SOA formation. This project involves two intensive measurement campaigns to obtain detailed characterization of primary VOC emissions in New York City. These measurements include hydrocarbon and oxygenated VOCs from both combustion and non-combustion (e.g. VCPs) emission sources. This will be accomplished by deploying a 2-channel in situ gas chromatograph with thermal desorption preconcentration and election ionization high-resolution time-of-flight mass spectrometric detection to an urban site in northern Manhattan in coordination with the New York City metropolitan Measurements of Emissions and TransformationS (NYC-METS) summer and winter field deployments. By quantifying the primary VOC emissions in New York City during both the summer and wintertime, the project will also lead to a better understanding of how heat affects VOC chemistry in urban areas and how emission profiles change with season in New York City.