| Fourier transform infrared (FT-IR) spectroscopy is used to evaluate the quality of various agriculturally-derived oils used as feedstocks for biodiesel production and the quality of the produced biodiesel. Most important to feedstock quality is the assessment of free fatty acid (FFA) content as evidenced by acid peaks in the spectrum that are separate from ester peaks. Many qualitative differences exist between the oil feedstock and the transesterified methyl esters and these will be highlighted. More importantly, quantitative assessment of the transesterification reaction is possible by monitoring the appearance of new methyl peaks in the FT-IR spectra. Quantitative results will be presented as equations that utilize the methyl peak areas intensities and positions in the FT-IR spectra to assess the extent of reaction. |