Flow injection analysis of free glycerol in biodiesel using a copper electrode as an amperometric detector

► In this study we develop a simple analytical method for quantification of glycerol based in a flow injection system. ► Low limit of detection was achieved (250 μg L−1). ► The only sample pre-treatment used was an extraction of glycerol from the biodiesel sample with water. ► Different types of biodiesel samples (B100) were analysed (from vegetable oils and animal fats). ► We concluded that proposed method proved useful for the control of the biodiesel samples quality.