Volatile organic compounds in snow in the Quebec‐Windsor Corridor

Abstract

Volatile organic compounds (VOC) were determined in snow to investigate the role of the snowpack as an exchange medium for atmospherically active compounds of anthropogenic and biogenic origin. The major question was which VOC species occur in snow and how the species identity and selected concentrations are related to the sampling area and environmental conditions. Samples were collected using a standardized sampling protocol in two distinct areas in six locations (near Mont‐Saint‐Hilaire, 45°33′06″N, 73°03′03″W (semirural) and Mont Tremblant, 46°20′11″N, 74°30′36″W (rural) in the heavily populated Quebec‐Windsor Corridor, Canada, with different characteristics regarding location and proximity to urban centers. A solid‐phase microextraction (SPME) procedure was employed for analysis, and VOC were identified using a gas chromatography method with mass spectrometric detection (GC/MS). Results revealed a broad spectrum of VOC in snow samples, including ethers, aldehydes, and aromatic and halogenated compounds, all of them active precursors for atmospheric reactions. Quantification was carried out for 11 aromatic and/or oxygenated compounds. Concentrations were found to be between 1.0 ± 0.2 ng/L (ethylbenzene) and 2.67 ± 0.06 μg/L (acetophenone), and limits of detection varied between 0.30 ng/L (benzene) and 78.2 ng/L (benzaldehyde). Principal component analysis was carried out to assess similarities between the sampling locations based on the types of species identified and concentration profiles. We discuss the implication of our results for atmosphere‐snowpack interactions of VOC including back trajectory calculations for the sampling dates.