Analysis of diesel engine exhaust by ultraviolet absorption spectroscopy

Ultraviolet absorption spectroscopy was used for the analysis of exhaust fr om internal combustion engines. This technique employs a single pass absorp tion cell with a high speed photodiode array detector. Differential absorpt ion was used to quantify analytes and to correct for changes in cell transm ission. Sulfur dioxide, ammonia, and nitric oxide were detected with little interference from other species. The results obtained using this method co mpared very favorably with the results obtained using infrared absorption a nd chemiluminescence techniques.