Above is the FTIR spectral overlay of biodiesel in diesel, the biodiesel peaks at 1741cm-1 (ester carbonyl stretch), 1170cm-1 (ester C-O stretch), 1196cm-1, and 1245cm-1 increase proportionally to concentration according to Beer's Law (Absorbance Law). This law is common to most spectroscopic quantitative analytical techniques and is used to create an oil analysis methods for used and in-process oils. This FTIR analysis technique is used to identify and quantitate the degree of oxidation and depletion of additives in an industrial hydraulic, gear, turbine, crankcase, compressor, or specialty oil. Similarly, FTIR analysis can be performed on greases and other very high viscosity lubricants. More information on this service is provided on our Oil and Fuel FTIR analysis page.