In the proposed procedure, a good analyte stabilization and sample
preparation was obtained by simply and fastmicroemulsion formation,
without surfactant and hazardous organic solvents. No significant
difference (t-test, pb0.05) was observed between the results obtained
by the proposed and reference comparative procedures. The recovery
test and the results of the figures of merit indicate a good sensitivity as
well as nomatrix effect. Thus, the proposed procedure can be considered
an attractive alternative for determining Na, K, Ca, and Mg by F AAS in
biodiesel samples.