Using proton nuclear magnetic resonance as a rapid response research tool for methyl ester characterization in biodiesel

Abstract

Reliable and rapid analysis remains a high priority for quality control in biodiesel production. Quantifying biodiesel with alternative analytical tools such as proton nuclear magnetic resonance ( 1 H NMR) can provide total methyl esters distributions without significant sample pretreatment. Using unique spectra of individual methyl esters, we investigate the feasibility of using 1 H NMR spectroscopy to identify and quantify relative and absolute concentrations of methyl esters in a biodiesel.

Transesterification of Coconut Oil Using Dimethyl Carbonate and TiO2/SiO2 Heterogeneous Catalyst

“…The 1 H-NMR spectrum of a typical sample presented in Fig. 2 is characterized by the presence of peaks at different chemical shifts commonly reported for biodiesel [25][26][27].…”

“…In addition to gas chromatography-mass spectrometry (GC-MS), another method that has been applied for biodiesel analysis is proton nuclear magnetic resonance ( 1 H-NMR) for its ability to provide complementary information regarding the molecular variability of the sample [25][26][27]. While the GC-MS provides detailed molecular weight information, the NMR technique is sensitive to unique molecular environments which yield unique spectra for different molecules.…”

Recent developments in microbial oils production: a possible alternative to vegetable oils for biodiesel without competition with human food?

“…Gas chromatography was the first method used for identification of lipids (Wynn and Ratledge 1997) but some prefer GCMS (Rattray et al 1975). Other methods such as HPLC (Rau et al 2005), Infra-red spectrophotometry (Peng and Chen 2008b) or NMR (Horst et al 2009) have also been used for the identification of lipids. …”

Influence of Kinetic Variables on Rubber Seed Oil Transesterification Using Bifunctional Catalyst CaO-MgO/SiO2

“…Other peaks observed in the region of 0.82 to 0.85 ppm represent the protons in the methyl end group, and the sharp multiplets in the region of 1.21-1.26 ppm originate from overlapping of CH 2 proton in the methyl ester mixture, representing the presence of unsaturated methyl esters 39 .…”