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Title: Portable, low-cost samplers for distributed sampling of atmospheric gases
Volatile organic compounds (VOCs) contribute to air pollution both directly, as hazardous gases, and through their reactionswith common atmospheric oxidants to produce ozone, particulate matter, andother hazardous air pollutants. There are enormous ranges of structures andreaction rates among VOCs, and there is consequently a need to accuratelycharacterize the spatial and temporal distribution of individual identifiedcompounds. Current VOC measurements are often made with complex, expensiveinstrumentation that provides high chemical detail but is limited in itsportability and requires high expense (e.g., mobile labs) for spatiallyresolved measurements. Alternatively, periodic collection of samples oncartridges is inexpensive but demands significant operator interaction thatcan limit possibilities for time-resolved measurements or distributedmeasurements across a spatial area. Thus, there is a need for simple,portable devices that can sample with limited operator presence to enabletemporally and/or spatially resolved measurements. In this work, we describenew portable and programmable VOC samplers that enable simultaneouscollection of samples across a spatially distributed network, validate theirreproducibility, and demonstrate their utility. Validation experimentsconfirmed high precision between samplers as well as the ability ofminiature ozone scrubbers to preserve reactive analytes collected oncommercially available adsorbent gas sampling cartridges, supportingsimultaneous field deployment across multiple locations. In indoorenvironments, 24 h integrated samples demonstrate observable day-to-dayvariability, as well as variability across very short spatial scales(meters). The utility of the samplers was further demonstrated by locatingoutdoor point sources of analytes through the development of a new mappingapproach that employs a group of the portable samplers and back-projectiontechniques to assess a sampling area with higher resolution than stationarysampling. As with all gas sampling, the limits of detection depend onsampling times and the properties of sorbents and analytes. The limit of detectionof the analytical system used in this work is on the order of nanograms,corresponding to mixing ratios of 1–10 pptv after 1 h of sampling atthe programmable flow rate of 50–250 sccm enabled by the developed system.The portable VOC samplers described and validated here provide a simple,low-cost sampling solution for spatially and/or temporally variablemeasurements of any organic gases that are collectable on currentlyavailable sampling media.  more » « less
Award ID(s):
2046367 1837882
PAR ID:
10496512
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
European Geophysical Union
Date Published:
Journal Name:
Atmospheric Measurement Techniques
Volume:
16
Issue:
19
ISSN:
1867-8548
Page Range / eLocation ID:
4681 to 4692
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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