An experimental procedure is presented that was developed by fifth-year
chemical engineering and industrial chemistry undergraduates at the
Federal University of Rio de Janeiro doing the discipline on Experimental
Organic Technology. The aim of this study was to apply the solvatochromic
effect of the dye Nile Blue chloride to the characterization of biodiesel/diesel
blends with different biodiesel content, using an alternative image
processing analysis method involving low-cost, simple, and rapid assays.
The effect of the solvatochromic dye Nile Blue chloride was monitored
using the software ImageJ, which is being used currently, yielding
rapid and effective responses. As an outcome, the students proposed
a procedure that had potential application to colorimetric determination
of biodiesel content in diesel oil. This gave students the opportunity
to put the knowledge acquired in the course into practice, by dealing
with issues concerning the fuels industry, making the learning process
more dynamic, engaging, and effective.