Temporal Variations of Cyclic and Linear Volatile Methylsiloxanes in the Atmosphere Using Passive Samplers and High-Volume Air Samplers
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- 作者：Lutz Ahrens ; Tom Harner ; Mahiba Shoeib
- 刊名：Environmental Science & Technology
- 出版年：2014
- 出版时间：August 19, 2014
- 年：2014
- 卷：48
- 期：16
- 页码：9374-9381
- 全文大小：385K
- ISSN：1520-5851
文摘
Cyclic and linear volatile methylsiloxanes (cVMSs and lVMSs, respectively) were measured in ambient air over a period of over one year in Toronto, Canada. Air samples were collected using passive air samplers (PAS) consisting of sorbent-impregnated polyurethane foam (SIP) disks in parallel with high volume active air samplers (HV-AAS). The average difference between the SIP-PAS derived concentrations in air for the individual VMSs and those measured using HV-AAS was within a factor of 2. The air concentrations (HV-AAS) ranged 22鈥?51 ng m鈥? and 1.3鈥?5 ng m鈥? for 危cVMSs (D3, D4, D5, D6) and 危lVMSs (L3, L4, L5), respectively, with decamethylcyclopentasiloxane (D5) as the dominant compound (75% of the 危VMSs). Air masses arriving from north to northwest (i.e., less populated areas) were significantly less contaminated with VMSs compared to air arriving from the south that are impacted by major urban and industrial areas in Canada and the U.S. (p < 0.05). In addition, air concentrations of 危cVMSs were lower during major snowfall events (on average, 73 ng m鈥?) in comparison to the other sampling periods (121 ng m鈥?). Ambient temperature had a small influence on the seasonal trend of VMS concentrations in air, except for dodecamethylcyclohexasiloxane (D6), which was positively correlated with the ambient temperature (p < 0.001).