Speciation of organic carbon in the atmosphere

Organic compounds often are the largest contributors to the fine particle concentration in the atmosphere of cities as well as many rural areas. Typically 30 to 40 % of the mass concentration of those particles smaller than one or two micrometers in diameter consists of organic material. In many cases, only the total organic carbon concentration is known from measurements made by thermal evolution and combustion analysis. In this presentation, methods will be described for investigation of the organic compound distribution that exists within the atmospheric particle mixture. A mass balance approach will be adopted that seeks to relate the individual organic compounds and compound classes to their relative abundance in the overall particulate organic compound and fine particle mass concentration in the atmosphere.