The carbon components in indoor and outdoor PM(2.5) in winter of Tianjin

To study the carbon components in indoor and outdoor PM(2.5), the samples of PM(2.5) were collected from Nankai University in December 2015. The contents of eight carbon components were analyzed to use the thermo-optical reflection method. The results indicated that organic carbon (OC) mass concentration was 17.01, 19.48 and 18.92 µg/m(3) in outdoor, dormitory and laboratory; elemental carbon (EC) mass concentration was 7.97, 3.56 and 3.53 µg/m(3) in outdoor, dormitory and laboratory; and the total carbon aerosol was the proportion of more than 23% of PM(2.5) samples. Lower wind speed and higher relative humidity were helpful to the accumulation of PM(2.5). The ratio of OC/EC was > 2, and the SOC/OC ratio was > 30%, indicating that SOC was a crucial component indoors and outdoors. About 72% and 85% of the outdoor OC entering dormitory and laboratory environment, and about 59% and 71% of the outdoor EC entering dormitory and laboratory environment. Factor analysis of the eight carbon fractions indicated that the sources of OC and EC in outdoor, dormitory and laboratory is different.