Determinação de glicerol livre e total em amostras de biodiesel por método enzimático com detecção colorimétrica

Abstract

A method based on enzymatic activities was developed using three enzymes (glycerokinase, glycerol-3-phosphate oxidase and peroxidase) and colorimetric detection for the determination of glycerol in biodiesel. The enzymatic conversion of glycerol produces H 2O 2 that is eliminated by the action of peroxidase, an oxygen acceptor and 4-aminoantipirine, producing water and a colored compound, which was analyzed. This method showed good linear correlation coeffcient (r = 0.9937) in the concentration range of 4.95 x 10 -5 to 3.96 x 10 -4% (w/w) and had experimental limits of detection and quantitation of 7.10 x 10 -6 and 2.10 x 10 -5% (w/w), respectively.