From all the contaminants that impair the performance of biodiesel in diesel engines (alkali metals, residual alcohol, soaps, free glycerol, and residual glycerides) (Atadashi et al., 2011 and Gomes et al., 2010), metals have received special attention by researchers due to the acceleration of biodiesel degradation processes compromising the storage time of this biofuel (Jain and Sharma, 2014 and Sarin et al., 2009).