Ambient Sample Capture Apparatus Provides VOC Speciation using Next Generation Air Monitoring Networks

Abstract:

Performance of modern low-cost sensor networks is fast approaching the realm of traditional reference instruments. Electrochemical and PID gas detection levels are now often in the low single-digit-ppb domain, and inexpensive optical particle counters can show impressive correlation to reference-grade analyzers. However, a major drawback remains the inability to speciate detected levels of Volatile Organic Compounds (VOCs).

We solve this problem with an Apis sensor network deployment near oil and gas drilling sites in the Broomfield, Colorado region. The network uses sensitive broadband PID sensors, sophisticated anomaly detection, and a new Capture Box accessory to collect ambient air samples for lab analysis using tried and trusted methods outlined in the EPA's TO-15 for subatmospheric pressure sampling using SUMMA canisters. However, rather than opening the canister valve in person at some random time, our network senses ambient VOC anomalies in real time to trigger remotely-operated canisters. The network then automatically informs a field technician when and where to retrieve the samples for detailed GC/MS analysis back in the lab.

The time and money typically lost by the hit-and-miss nature of traditional ambient sampling methods is now refocused on sampling only during pollution events recognized in real time, vastly increasing the efficacy and cost-effectiveness of the whole detection network, and we have already made some startling discoveries that would not have been possible without real time canister triggering. We are now deploying similar VOC capture stations in a variety of industrial and community projects, and are looking for new partners to further explore the usefulness of this technology.