Application Note

FTIR Analysis of Hydrocarbon Contamination in Diesel Exhaust Fluid (DEF)


DEF is a colorless liquid which is beneficial in the reduction of nitrogen oxide (NOx) emissions from diesel engines. The Selective Catalytic Reduction (SCR) system injects the DEF through a catalyst, converting the harmful nitrogen oxides into nitrogen, water, and carbon dioxide. Problems can occur if contaminated DEF is put into the engine. The composition standard was published by the International Organization for Standardization (ISO), to ensure the problems listed above don’t occur and no NOx gasses are released into the atmosphere.

This application note describes a simple FTIR (Fourier Transform Infrared Spectroscopy) method on the PerkinElmer Spectrum Two+ using a solid phase extraction system that was developed by Orono Spectral Solutions to determine the concentration of hydrocarbon contamination in DEF and other liquid urea feedstocks.