Abstract |
Several volatile organic compounds (VOCs) have been identified as candidates for tracers of fine particulate carbon and Extractable Organic Matter (EOM) from mobile sources. The identification resulted from a multiple screening procedure in which the ambient concentrations of a candidate VOC were first required to have both a high correlation with ambient concentrations of fine particulate Pb, a well established tracer of mobile source emissions, and a low correlation with soil-corrected fine particle potassium (K'), a previously demonstrated tracer of woodsmoke, using measurements from an airshed in which these were the dominant sources. Each VOC surviving this screening was then substituted in place of Pb, and along with K', in multi-linear regression representations of the carbon and EOM data. Successful VOCs resulted in a multiple correlation coefficient (r(sup 2)) at least as good as with K' and Pb, and estimates of the woodsmoke and mobile source contributions virtually the same as with K' and Pb. The reasonableness of these VOCs as mobile source tracers was affirmed by considering what is known about the abundance of those VOCs in woodsmoke and mobile source emissions. |