Complexometric Titration of Rare Earth Elements. Dissolution of the Rare Earth Oxalate with Ethylenediaminetetraacetic Acid and Back Titration with Magnesium Sulfate

Abstract The processes for dissolution of the oxalate and complexometry to determine the small amounts of rare earth rapidly and accurately, were studied. Crystalline rare earth oxalate was precipitated and filtered. The precipitate was dissolved completely with EDTA in alkaline solution and the excess of EDTA in solution was back titrated with standard magnesium sulfate solution. By this procedure, rare earth in the range of a content about 1 to 5mg., was determined rapidly with a good accuracy.