MONITORING OF AIRBORNE ORGANIC VAPORS USING ION MOBILITY SPECTROMETRY

Automated, continuous monitoring of organic vapors in air under three field designs for plume drift was demonstrated using a hand-held ion mobility spectrometer (IMS) in characterizing IMS behavior as a point sensor. In one field study, the IMS was placed 50cm from a 9m2 grass plot contaminated with methylsalicylate and response to airborne vapors was recorded during a 13 hr period of atmospheric turbulence to illustrate susceptibility of point sensors to wind direction. A similar study under near-quiescent atmospheric conditions was made using dimethylsulfoxide. In a third study, the plume from a point source of dipropyleneglycolmonomethylether was interrogated over a 25m × 12m grid downwind with windspeeds of 6~18kmh−1. Laboratory studies were used to measure instrumental response times and influences from potentially interfering atmospheric organic pollutants. © 1990, Taylor & Francis Group, LLC. All rights reserved.