초록/요약

Carbon fractions can be classified as organic carbon (OC) and elemental carbon (EC) by thermal-optical definition. In the NIOSH protocol, OC is divided by four OC fractions (OC1~OC4) and OP is determined when transmission of laser light attains its original intensity after oxygen was added to the combustion atmosphere. EC is divided by six EC fractions (EC1~EC6). In this study, to understand the characteristics of carbon fractions in PM2.5, especially, the characteristics of temperature-resolved OC and EC fractions at Anmyeon Island which is a background area in Korea, routine measurements of OC and EC with other carbon fractions (WSOC and HULIS-C) and organic speciations were carried out during two years. Among temperature-resolved OC and EC fractions, we found that OP had distinct seasonal characteristics. OP concentrations decreased in summer, while, increased in fall. The split points by the transmission correction between OC and EC had four different characteristics during the sampling period. The split points were mainly located in OC4 fraction region in the summer samples and this might be related to the high oxidation condition of PM2.5 sample during summer. OP had significant correlation with HULIS-C (r2=0.52, P<.01) in summer. But in the other season, OP has significant correlation with HULIS-C (r2=0.85, P<.01) and Levoglucosan (r2=0.46, P<.01). When principle component analysis (PCA) was applied to the measurement, OP was extracted in factor 1 accounted for 28% of