ABSTRACT
In this chapter, the role of gas/particle partitioning within filters during sampling as a cause of sampling artifact errors is explored. First, a mass balance model is developed to explain variations of particulate organic carbon concentration with sampling face velocity, sampling duration and filter type. Second, preliminary results of experiments to estimate lifetimes of atmospheric semi-volatile organic compounds within sampling filters are presented. Organic carbon collected on backup filters could then be partly due to adsorption of organic vapor volatilized from collected particulate matter and should not be used to correct for adsorption artifact. The difference reflects the assumptions and uncertainties associated with the quantities used in the mass balance model and with the estimates of residence time from loss rates of syringe spiked filters. A diffusion-based mass balance model indicates that it is reasonable to expect vapor adsorption on filters to vary with sampling face velocity, sampling duration and filter type.
