[Uncertainty analysis of gas/particle partitioning of atmospheric polycyclic aromatic hydrocarbons]

During the period from August 10, 2010 through August 14, 2010, particle and gas phase PAHs were collected and analyzed using double filters plus PUFs (Poly Urethane Foam) sampling system, and the uncertainties of gas/particle partitioning coefficients of PAHs were investigated using the propagation of errors formulas. The results showed that low-molecular weight PAHs such as naphthalene, acenaphthylene, acenaphthene and fluorene possessed the strong breakthrough capacity with the breakthrough rates close to 50% in double PUF cartridges. The corrected K(p) values based on the sorption of PAHs to the primary filter were more than an order of magnitude higher than those without sorption correction for naphthalene, acenaphthylene and acenaphthene. The uncertainties for all the 19 PAHs ranged from 28.14% to 50.37% based on the standard error propagation formulas, with higher values for volatile and involatile PAHs and lower values for semi-volatile PAHs. The results also showed that the uncertainties of K(p) were mainly contributed from the measurements of particle (average variance contribution was 77.9%) and gas (average variance contribution was 22.0%) phase PAHs while the contributions of total suspended particle were ignorable. Thus, getting more accurate data for gaseous PAHs using an appropriate sampling system is the key to increase the accuracy of gas/particle partitioning coefficients of PAHs.