A new way to detect polluting raw vegetable oil in biodiesel blends

Scientists in Brazil have developed a new method for verifying the purity and quality of biodiesel. The pioneering new technique uses nuclear magnetic resonance (NMR) spectroscopy, according to spectroscopynow.com.

Biodiesel and biodiesel blended fuels are increasingly being used around the world in an attempt to cut down dependency on unsustainable fossil fuels in both public and private transport systems. Purity, however, can be a problem with the biofuel, with raw vegetable oil rather than processed, transesterified oil often being used in the biodiesel market. The use of raw vegetable oil in biofuel increases pollution, lowers the quality of the fuel, and can cause damage to engines.

NMR spectroscopy uses the magnetic properties of certain nuclei to determine the physical and chemical properties of the atoms or molecules in which they are contained. Gustavo Shimamoto, Luis Bianchessi, and Matthieu Tubino of the Institute of Chemistry, University of Campinas (UNICAMP) in Brazil claim their new NMR approach can quickly and easily distinguish between biodiesel and raw vegetable oil. Univariate and multivariate calibrations of IR spectra are the standard for quality analysis of biodiesel blends, however, this method cannot detect raw vegetable oils in biofuels.

"The proton NMR method is a more practical and efficient alternative to the official method," the team write in their study for The International Journal of Pure and Applied Analytical Chemistry.

According to spectroscopynow.com, NMR spectroscopy is expensive, but fast. The University of Campinas teams claims it can carry out analyses of biodiesel with a 95% confidence level.