Method for measuring mass fraction of aluminum oxide in aluminum water treatment agent by potentiometric titration method

The invention discloses a method for measuring the mass fraction of aluminum oxide in an aluminum water treatment agent by potentiometric titration. The method comprises the following steps: weighing a sample; dissolving with water without carbon dioxide, transferring into a volumetric flask, diluting to the scale, and shaking uniformly to obtain a test solution A; transferring the test solution A into a beaker by using a pipette, adding a hydrochloric acid solution, boiling, transferring into an EDTA solution by using the pipette, adjusting the pH by using an ammonia water solution, adding an acetic acid-sodium acetate buffer solution, boiling, cooling, transferring into a potentiometric burette, washing the beaker by using water in three times, and transferring all washing liquid into the potentiometric burette for titration; a potentiometric titrator being provided with a copper ion selective electrode and a silver-silver chloride reference electrode, setting the maximum single liquid adding amount to be 6