Analysis of biodiesel, diesel and gasoline by NMR spectroscopy – A quick and robust alternative to NIR and GC

Abstract

1H NMR spectroscopy is presented as a routine analysis for diesel mixed with biodiesel and gasoline. Results of NMR spectroscopy and the orthogonal gas chromatography method show identical results.

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.…”

Molecular Properties of Fatty Acid Mixtures Estimated by Online Time-Domain NMR

“…High-resolution nuclear magnetic resonance (NMR) spectroscopy is a standard technique for molecular structure and molecular mobility investigations of different substances and is well established in the chemical analysis of liquid fuels [3,[6][7][8][9][10]. However, traditional high-resolution NMR spectrometers are hardly applied to industrial process control due to their open magnetic field, large size and high price and the required cryogen use.…”

1H NMR and Multivariate Calibration for the Prediction of Biodiesel Concentration in Diesel Blends

“…Nuclear Magnetic Resonance (NMR) is a versatile spectroscopic method that has become one of the most powerful techniques for the elucidation of the structure of chemical compounds. Although 1 H NMR is frequently used for monitoring biodiesel synthesis and quality [6], few reports describe the use of NMR for biodiesel blend level determination [3,7,8]. In the first works [7,8], the integrals of the peaks at 3.5-3.7 ppm (methoxy group of biodiesel), 0.5-3.0 ppm (methyl and methylene hydrogens from biodiesel and diesel), and 5.3-5.4 ppm (olefin hydrogens of biodiesel) were used to quantify biodiesel in biodieseldiesel blends.…”