versão impressa ISSN 0100-4042
VALDEZ, Higor da Cal et al. Free and total glycerol determination in biodiesel samples by enzymatic method with colorimetric detection. Quím. Nova [online]. 2012, vol.35, n.3, pp. 601-607. ISSN 0100-4042. http://dx.doi.org/10.1590/S0100-40422012000300028.
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 H2O2 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 coefficient (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.
Palavras-chave : glycerol content; biodiesel; enzymatic-colorimetric method.