Calibration and Application of a Passive Air Sampler (XAD-PAS) for Volatile Methyl Siloxanes

• Published in: Environmental science & technology Vol. 47; no. 9; pp. 4463 - 4470
• Main Authors: Krogseth, Ingjerd S, Zhang, Xianming, Lei, Ying D, Wania, Frank, Breivik, Knut
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 07.05.2013
• Subjects: Air - analysis; Air pollution; Analysis methods; Applied sciences; Atmospheric pollution; Calibration; Environmental testing; Exact sciences and technology; Ion Exchange Resins; Pollution; Polystyrenes - chemistry; Quality Control; Sewage treatment plants; Siloxanes - chemistry; VOCs; Volatile organic compounds; Volatilization; Canada; North America; Ontario; America; Toronto Ontario Canada; Passive detection; Benzene(divinyl) copolymer; Sampler; Organic siloxane; Air pollution; Suburban zone; Volatile organic compound; Calibration; Ion exchange resin; Organic compounds; Styrene copolymer
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es400427h

Because the atmosphere is key to understanding the environmental behavior of volatile methyl siloxanes (VMS), a variety of reliable air sampling methods are needed. The purpose of this study was to calibrate and evaluate an existing, polystyrene–divinylbenzene copolymeric resin-based passive air sampler (XAD-PAS) for VMS. Sixteen XAD-PAS were deployed for 7–98 days at a suburban site in Toronto, Canada, while the VMS concentration in air was monitored by an active sampling method. This calibration and a subsequent field test further allowed for investigation of the temporal and spatial variability of VMS in the region. Uptake in the XAD-PAS of octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and three linear VMS was linear throughout the whole deployment period. Sampling rates were between 0.4 and 0.5 m3/day. The XAD-PAS measured ∑VMS concentrations ranged from nondetects in rural areas (n = 3), to 169 ± 49 ng/m3 in the urban region (n = 21), to levels above 600 ng/m3 at sewage treatment plants (n = 2). Levels and composition of VMS within the urban area were remarkably uniform in space. Levels, but not composition, were highly variable in time and weakly correlated with temperature, wind speed, and wind direction.