P. Jurcek et F. Skacel, THE POSSIBILITIES OF POTENTIOMETRIC DETERMINATION OF POTASSIUM IN SOME SILICATE RAW-MATERIALS, Ceramics-Silikaty, 38(2), 1994, pp. 93-98
Potentiometry using the potassium ion-selective electrode can be conve
niently employed to determine rapidly the approximate content of K2O i
n silicate raw materials. For the determination, the dried and ignited
sample of the material is decomposed by reflux boiling in hydrochlori
c acid (9 mol dm-3). Aliquote amounts are taken from the suspension ob
tained so as to receive a resulting K2O content over the range of 10(-
2) to 1.5 x 10(-5) mol dm-3 at pH of 0.7 to 0.9. Under the given condi
tions, the interfering effect of hydrogen ions occurs only at pK+ = 5.