Elemental composition of teff (a gluten-free grain), maize and wheat: Staple crops in the Main Ethiopian Rift Valley

•Toxic and essential elements were measured in staple cereals of the Main Ethiopian Rift Valley.•Teff (a gluten free diet) contained more Mg, Ca, Na, Fe, Mn, Sr, Cu, As, and Pb than wheat and maize.•Cd and Pb levels were below the Codex standards for cereal grains except one teff sample that exceeded the Pb standard.•This work adds to the nutritional database of these cereals in Ethiopia and beyond.