Source contributions to carbonaceous species in PM_2.5 and their uncertainty analysis at typical urban, peri-urban and background sites in southeast China

Determination of ¹⁴C and levoglucosan can provide insights into the quantification of source contributions to carbonaceous aerosols, yet there is still uncertainty on the partitioning of organic carbon (OC) into biomass burning OC (OC_bb) and biogenic emission OC (OC_bio). Carbonaceous species, levoglucosan and ¹⁴C in PM_2.5 were measured at three types of site in southeast China combined with Latin hypercube sampling, with the objectives to study source contributions to total carbon (TC) and their uncertainties, and to evaluate the influence of levoglucosan/OC_bb ratios on OC_bb and OC_bio partitioning. It was found reliably that fossil fuel combustion is the main contributor (62.90-72.23%) to TC at urban and peri-urban sites. Biogenic emissions have important contribution (winter, 52.98%; summer, 45.71%) to TC at background site. With the increase in levoglucosan/OC_bb ratios, the contribution of OC_bio is increased while OC_bb is decreased in a pattern of approximate natural logarithm at a given range.