The stable carbon isotope composition of atmospheric PAHs

A method for compound-specific stable carbon isotope analysis of atmospheri c polycyclic aromatic hydrocarbons (PAHs) in carbonaceous aerosols is descr ibed. Atmospheric aerosol samples containing PAHs (C-10 to C-20) were colle cted on filters using a high-volume sampling technique, solvent extracted, taken through a cleanup procedure, separated by gas chromatography, oxidize d to CO2 on-line, and introduced into an isotope ratio mass spectrometer fo r analysis. The method can be used to determine the isotope composition of a few nanograms of PAHs. This technique was used to analyse and compare the isotope composition of atmospheric PAHs from standards, as well as two sam ples from urban and rural locations. Isotopic variability in atmospheric PA Hs is greater than measurement uncertainties which makes this a potentially useful technique for source identification when used together with concent ration measurements. (C) 1999 Elsevier Science Ltd. All rights reserved.