Application of raman spectroscopy to monitor and quantify ethyl esters in soybean oil transesterification

摘要: Biodiesel (FA esters) has become very attractive as an alternative diesel fuel owing to its environmental benefits. Transesterification is the most usual and important method make biodiesel from vegetable oils. This article investigates potential for using Raman spectroscopy monitor quantify transesterification of soybean oil yield ethyl esters. The differences observed in spectra after were a peak at 2932 cm−1 ( $$v_{CH_2 }$$ ), displacement v C=O band 1748 1739 cm−1, bands 861 (v R-C=O C-C) 372 (δ CO-O-C). Uni- multivariate analysis methods used build several analytical curves then applied known samples, treated unknowns, test their ability predict concentrations. best results achieved by Raman/PLS calibration models (where PLS=partial least squares regression) internal normalization standard =C-H band). correlation coefficient (R 2) values so obtained 0.9985 0.9977 validation. Univariate regression between concentration increasing intensity or showed R 2 0.9983 0.9742, respectively. Although spectroscopic are less sensitive than chromatographic ones, data can be correlated with other techniques, allowing quality quickly assessed.