Optimization of a method for the simultaneous determination of glycerides, free and total glycerol in biodiesel ethyl esters from castor oil using gas chromatography

► A new method for the determination of contaminants in biodiesel was developed. ► Glycerides, free and total glycerol were determined in castor oil biodiesel. ► Only one method was used to determine these contaminants by gas chromatography. ► ANP recommends the use of three methods for this analysis. ► Results show that ASTM D 6584 and EN 14105 should be employed with 250 μL of MSTFA.