[Chemical Constitution and Carbon Isotopic Compositions of PM in the Northern Suburb of Nanjing in Spring].

PM is an important atmospheric pollution component and has a complicated composition. The chemical constitution of PM in Nanjing northern region during March 2016 was analyzed using the Dinoex ICS-3000 and ICS-2000 ion chromatograph and DRI Model 2001A thermal/optical carbon analyzer, and the carbon isotopic compositions were analyzed using EA-IRMS from Thermo Scientific in order to explore pollution behaviors and source apportionment of PM. The results showed that the mean concentration of atmospheric PM was (106.16±48.70) μg·m, which equated with heavy pollution. Meanwhile, 88% of the samples exhibited the presence of the secondary organic pollutants. The average concentration of secondary organic carbon (SOC) was (3.58±2.78) μg·m and this high concentration was attributed to the reaction of O with atmospheric hydrocarbons under ultraviolet light on sunny days. In addition, δC in PM ranged from -26.56‰ to -23.75‰ and the mean was (-25.47‰±0.63‰). Combining the various analyses, we concluded that atmospheric PM for the study area was mainly derived from coal combustion, vehicle exhaust, geology (natural sources) and biomass burning.