(ISE = Ion Selective Electrod)

YU Dian-ying

Abstract: A Consective procedure of determining calcaciurn and magneslum in ceramic raw materials with ISE has been worked out here. With silver sulphite electrode as the indicator electrode, complex EGT A-Ag as the 1 iqu id indicator, Ca²⁺ and Mg ^{2 +} can be titrated with EGTA and CYDTA sequentially without another aliquot of test solution By adding 5m mole potassium sodium tartrate to the aliquot of 25ml, the interfering ions Fe³⁺ , Al³⁺,Ti⁴⁺ can be masked at PH=9.5-10.0. The concentration of EGTA, CyDTA is 1×10^-3M, 5×l0^-3M respectively. It is found that the reaction rate between YDT A and Ca²⁺ (Mg²⁺） is faster than th e r,eaction rate between ETDA.

Keywored: Calcucium, Maguesium in Ceramic