Impedimetric sensing of the biodiesel contents in diesel fuels with a carbon paste electrode pair

► An electrochemical chamber with hydrophobic electrode pair was provided for measuring the impedance of oily substances. ► The first impedimetric data for biodiesel and the related substances. ► The impedance data in low frequency can be used to estimate the blending ratio of biodiesel in no time. ► The resolution is good even in logarithmic scale.