Abstract: | Abstract Two methods for oxalate determination with a fluorideselective electrode are proposed. For oxalate amounts higher than 0.2 mmol, the joint precipitation of oxalate and standard fluoride with lanthanum(III) can be used. For smaller oxalate amounts, the precipitation of oxalate with excess of lanthanum(III) followed by back-titration with fluoride, is suitable. The end-points are located using the second derivative procedure and by means of the Gran method, respectively. |