FTIR Analysis for Quantification of Fatty Acid Methyl Esters in Biodiesel Produced by Microwave-Assisted Transesterification

Biodiesel was produced by microwave-assisted transesterification of soybean oil with methanol as esterifying agent and sodium methoxide as catalyst. Fourier transform infrared spectroscopy was employed as a fast and reliable analytical technique for the quantification of fatty acid methyl ester content in the produced biodiesel. The quantification was done with the use of a partial least squares model developed based on the infrared spectra obtained. It was shown that microwave irradiation is capable of reducing the reaction time when compared to conventional mechanically stirred reactors used for biodiesel production. In addition, quantification of fatty acid methyl ester content in biodiesel by Fourier transform infrared spectroscopy coupled to multivariate statistics was demonstrated feasible.