AUTOMATED IODIMETRIC DETERMINATION OF CU+, CU-2+ AND CU-3+ IN THE SUPERCONDUCTOR YBCO USING A MODIFIED GRAN PLOT TECHNIQUE

An automated potentiometric determination of the oxygen content of the superconductor YBCO is described. The end-point of the titration is found using a linear Gran plot technique. Suitable equations are derived by which the number of titration points can be considerably reduced and the titration can be stopped even before the equivalence point is reached. Automation of the iodimetric titration can be performed in an easy manner. During the titration a good estimate of the equivalence volume can be calculated using only two titration points.