Characterization of Odorous Industrial Plumes by Coupling Fast and Slow Mass Spectrometry Techniques for Volatile Organic Compounds

Authors:
Preprint
Publisher website
Google Scholar
Abstract
This study aimed to develop a technique to chemically characterize odor issues in neighborhoods of designated industrial zones with pronounced emissions of volatile organic compounds (VOCs). Due to the elusive nature of odor plumes, speedy detection with sufficient sensitivity is required to capture the plumes. In this demonstration, proton-transfer-reaction quadrupole mass spectrometry (PTR-QMS) was used as the front-line detection tool in an industrial zone to guide sampling canisters for in-laboratory analysis of 106 VOC species by gas chromatography-mass spectrometry (GC-MS). A 10-day PTR field screening period was conducted to determine suitable trigger VOC species with exceedingly high mixing ratios that were also likely the culprits of foul odors. Twenty canister samples were then collected, triggered by m/z 43, 61 (ethyl acetate fragments), m/z 73 (methyl ethyl ketone), or m/z 88 (morpholine) in all cases. Internal consistency was confirmed by the high correlation of key species in the PTR and trigger samples. Several long-lived halocarbons were exploited as the intrinsic internal reference for quality assurance. Oxygenated VOCs (OVOCs) accounted for 15% - 75% of the total VOC mixing ratios in the triggered samples. However, EA and MEK, the most prominent OVOC species, did not appear to have common sources with morpholine, which presented with PTR peaks incoherent with the other OVOCs. Nevertheless, these distinctive OVOC plumes were consistent with the more than one type of odor reported by local residents. To contrast with the triggered sampling, random samples in the same industrial zone and roadside samples in a major metropolitan area were collected. The pronounced OVOC content in the triggered samples highlighted the advantage over random grab sampling to address odor issues. This study demonstrates that the combination of fast mass spectrometry and slow GC-MS can achieve sensitivity, speed, and chemical identification to tackle elusive odor issues.

This publication has 34 references indexed in Scilit: