Online Measurement of Trace Compounds in Air

Air analysis includes the real-time measurement of gas and aerosol components in the atmosphere, in indoor work or living environments, and in closed manufacturing spaces. Such measurements may be related to climate change research, air quality, quality control, or process monitoring. At trace concentration levels, the chemical composition of air is complex and compounds of interest may be undergoing rapid changes in concentration related to, for instance, dynamic changes in their source. Because they are capable of resolving and simultaneously monitoring large numbers of compounds at sub ppb levels with extremely high time resolution, our TOFs are frequently used for online air measurements.

Volatile Organic Compounds (VOCs) are critically important constituents of air in all of the forementioned environments. The Vocus PTR-TOF is the most sensitive available mass spectrometer for online VOC analysis – able to detect sub-ppt components in seconds – and its high resolving power enables identification of individual compounds within complex mixtures, often replacing the need for GC before mass spectrometry.

The API-TOF is widely used with other chemical ionization schemes that are selective for organic compounds of varied volatitility. The EESI ionization source extends this sensitive, molecular analysis capability to the aerosol phase. Our atmospheric science customers have run the API-TOF on all 7 continents – making measurements at remote field sites and aboard mobile research platforms.

Adding an IMS dimension to MS analyses – with the IMS-TOF – can be of major benefit for online air analysis. For instance, atmospheric researchers are often faced with the problem that many molecules from organic aerosols cannot be sufficiently well identified based on MS alone. Yet, these identifications, especially for isomeric molecules, are crucial for establishing chemical mechanisms that inform climate models.

industrial Indoor Air Quality

Indoor Air Quality Monitoring at an Industrial Facility

A Vocus CI-TOF was placed in an industrial facility for 2 weeks to monitor the time evolution of the indoor air species present in a working environment. The high resolving power of the TOF mass spectrometer together with various soft ionization modes provided accurate identification of targeted species, and the portability of the instrument allowed for measurements in various indoor areas within a short period of time. Read More »

VOC Emissions Fingerprinting

Point Source Detection and VOC Emissions Fingerprinting in Chinese Megacities

The Vocus PTR-TOF is a robust, low-power, mobile instrument that measures VOCs in air in real time, addressing environmental and industrial problems not accessible by traditional mass spectrometry. In this application note, patterns of VOC emissions from a Vocus PTR-TOF S mobile laboratory are shown around a Chinese megacity, including near a petrochemical facility. Read More »