Source Apportionment

Source Apportionment of Ambient VOC Pollutants and Fine Particulates

Simultaneous measurement of hundreds to thousands of VOCs
Field deployable and capable for mobile measurements

Ultra-low limits of detection in seconds
Data compatible with matrix factorization and point source identification algorithms

Background

Source Apportionment of VOC pollutants

Ambient air can contain hundreds of thousands of volatile organic compounds (VOCs) at trace concentrations. Emissions from multiple sources and other chemical processes are often mixed together, and this complex mixture is dynamic in composition and concentration across location and time.

With modern machine learning techniques, matrix factorization approaches, or other correlation analysis, researchers or regulatory authorities can use Vocus CI-TOF measurements to “untie” or “unmix” sources. The end result is the ability to identify major contributors to pollution. The Vocus CI-TOF is ideal for this application because it measures ambient air directly in real time, has a fast time-response, measures a wide range of VOCs simultaneously and sensitively, and is not affected by changes in ambient humidity. The unsurpassed mobility offered by Vocus CI-TOF allows for direct localization of VOC hot spots at small to large geographic scales.

The techniques for source apportionment of ambient VOC and fine particulates were developed using TOFWERK instrumentation, and TOFWERK remains a leader in this field.

Solutions

Real-Time VOC Analysis Using the Vocus CI-TOF
- Highest sensitivity available with sub-ppt limits of detection
- High mass resolving power enables identification of individual compounds within complex mixtures
- Real-time and fast data output capturing rapid changes in VOC concentrations and suitable for mobile monitoring
- Full spectrum acquisition allows measurements of wide range of compounds simultaneously
Source apportionment of VOC pollutants at a Chinese petrochemical facility. A) time series of a large number of individual VOC species measured with the Vocus CI-TOF. B) time series and contribution to total VOC of individual sources, determined using matrix factorization. C) mass spectra of the individual sources.