Stable carbon isotope composition and distribution of n-alkanes: Evidence for biogenic contribution to airborne particulates in the Lower Fraser Valley, British Columbia

In this Health Canada sponsored study (Toxic Substance Research Initiative, TSRI), the stable carbon isotope compositions of individual n-alkanes (C₂₁–C₃₁) extracted from airborne particles were determined using Gas Chromatography-Isotope Ratio Mass Spectrometry. Similarly, quantification of the n-alkanes (C₁₄–C ₃₆) was determined using Gas Chromatography-High Resolution Mass Spectrometry. A six-month study (March through August, 2001) was conducted at various locations within the Lower Fraser Valley, B.C. to investigate temporal or spatial changes in isotope composition or concentration of the n-alkanes. The goal is to assess their use in determining sources of airborne particles.; δ13C values for the n-alkanes ranged from −28.5‰ to −34.4‰, and differed depending on whether it was an odd numbered carbon chain or an even carbon chain. The odd carbon chains were depleted in 13C compared to the even carbon chains, and this was especially evident in May to August. (Abstract shortened by UMI.)...