Determination of biodiesel blend levels in different diesel samples by 1H NMR

The use of 1H NMR to quantify different methyl biodiesels in diesel from different sources is described. Biodiesel samples from soybean and castor oils, which have different fatty acid compositions, and three diesel fuels, which have distinct chemical compositions, were used to prepare biodiesel blends (0.5–30%, v/v). These samples were analyzed by 1H NMR and some relationships of integrals were employed to construct calibration curves. The results indicated that the quantification of biodiesel in diesel by 1H NMR is not affected by either biodiesel or diesel types and thus this technique is especially valuable for such determination.