The development of an active personal ozone sampler using a diffusion denuder

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:197388

Geyh, A S; Wolfson, J M; Koutrakis, P ^[1]; Mulik, J ^[2]

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1. Harvard Univ., Boston, MA (United States). School of Public Health
2. Environmental Protection Agency, Research Triangle Park, NC (United States)

Personal, microenvironmental and indoor ozone monitoring is currently carried out using a passive sampling device which is both light-weight and inexpensive. However, the collection properties of these samplers have been found to be sensitive to wind effects and sampler placement, thus limiting their potential use for personal monitoring. In addition, because of their relative insensitivity, these samplers cannot be used for short-term monitoring of ozone at low concentrations. In response to these problems the authors are developing a light-weight active ozone sampler which uses a single tube diffusion denuder for sample collection. The new single tube diffusion denuder (STTD) consists of a 1.4 cm (ID) x 10 cm etched Pyrex tube attached to a very small, low-flow, relatively low-cost personal pump. Tube diameter and length were chosen to maximize collection efficiency at a sampling rate of 65 mL/min. The tube is coated with a nitrite reagent which has been successfully used in the passive ozone samplers. Variations in relative humidity, ozone concentration, and total ozone exposure have relatively small affects on the accuracy and precision of the STTD. In addition, the low limit of detection (LOD) of approximately 20 ppb hrs gives a tenfold increase in sensitivity over the passive samplers for which a 200 ppb hr LOD has been determined. This new active sampler thus makes possible both short-term personal and microenvironmental monitoring.

• OSTI ID: 197388
• Report Number(s): CONF-9405167--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORING
AIR SAMPLERS
DESIGN
INDOOR AIR POLLUTION
OZONE