Die Oxidelektrode als Indikator bei der Amperometrischen Titration von Metallionen MitÄDTA

摘要

The equivalence point in chelatometric titrations can be indicated amperometrically, if a pin of platinum, coated with an oxide, is used as anode and bright platinum as cathode. A voltage of 0,8 to 1,0 volt is put on the electrodes. The current, flowing between the electrodes, increases very much, if there is an excess ofEDTAin the solution. Following oxides are suitable for coating the anode: thallium(III)-oxide, nickel(III)-oxide and cobalt(III)-oxide. The titration curve is either V- or angle-shaped, according to the cation.