Automated Monitoring of VOCs with a Compact Gas Chromatography-Proton Transfer Reaction Mass Spectrometer (GC-mVocus)

Volatile organic compounds (VOCs) are emitted from a wide variety of biogenic and anthropogenic sources. VOCs transform in the atmosphere, forming ozone and oxygenated VOCs (OVOCs), which in turn can form fine particulates or condense onto preexisting particulate matter (PM). Both ozone and fine PM are deleterious to human health and alter the Earth’s climate. Measurements of (O)VOCs are necessary to model the sources and sinks of harmful atmospheric chemicals. Progress in this area is limited, however, by the lack of field-deployable instrumentation capable of proving detailed molecular information. The goal of the proposed work is to develop a hybrid gas chromatograph and miniature proton transfer reaction Vocus mass spectrometer (GC-mVocus) instrument capable of real-time molecular-level chemical characterization of VOCs and OVOCs. Specific tasks in Phase I include characterizing the mVocus, developing the GC method, and developing automated data analysis and display software for the combined instrument. The result of Phase I will be the design and operating procedure of a prototype GC-mVocus that will be built and demonstrated in Phase II in a field campaign. The result of Phase II will be a GC-mVocus instrument that is capable of real-time, robust, and sensitive measurements of VOCs and OVOCs.