Determination of total phosphorus in biodiesel by ion chromatography

•A simple and efficient method for the determination of phosphorus in biodiesel by ion chromatography (IC) was proposed.•Biodiesel samples were treated by saponification-ashing-dissolution method, which improved the precision of the method.•The content of phosphorus at different temperatures was determined by IC method, and the maximum inorganic phosphorus content at different temperatures was obtained.•The phosphorus content in biodiesel was studied by IC method and ICP-OES method.•The phosphorus content in different kinds of biodiesel (soybean oil biodiesel and jatropha seed oil biodiesel) was studied.