Three-component deep eutectic solvent-based microextraction approach for biodiesel quality control: Determination of water and metals.

Biodiesel is an important alternative fuel produced by blending biofuels with petroleum diesel. Biofuel production is usually carried out by catalytic interesterification of animal fats or vegetable oils, followed by the removal of by-products and catalysts through washing with water. Residual amounts of water and catalysts can accelerate fuel biodegradation and contribute to the corrosion of metal surfaces.