Application of Methods for Determining Total Organic Contribution to Diesel Particulates

This paper describes the laboratory effort to relate quantities of diesel particulate volatile organics obtained by DFI/GC™ to those obtained by traditional methods of organic analysis. Experiments were designed to investigate the potential usefulness of DFI/GC for determining the organic fraction and unburned lubricating oil contributions of diesel particulate emissions for future technology engines. A 1991 Caterpillar 3176 was used to generate samples during several heavy-duty engine test cycles, including the cold- and hot-start transient FTP and several steady-state conditions. Particulate-laden filter samples were then analyzed for organics by DFI/GC, solvent extraction, and vacuum volatilization. Results obtained using the three techniques were compared using statistical analysis techniques. Results showed that DFI/GC is extremely useful for directly determining the organic fraction of diesel particulate, and provides a better estimation of unburned lubricating oil contribution to the organic fraction than the other methods evaluated.