Synthesis of Calcium-Zincon Complex and Exploitation it in the Assembly of Calcium Ion-Selective Electrode.


A new calcium ion-selective electrode was assembled from complex synthesized by calcium ion and zincon which doped in pvc with suitable mediator and solvent . The prepared complex was identified by UV- Visible and IR spectrophotometry. The new electrode was characterized by its high slope (29.55 ±0.02 mV/decade) compared with calcium phosphate electrode (26.67±0.022 mV/decade) and long lifetime (10 months) . The linear range of the electrode was 10-5-10-1M and the detaction limit was 10-5M . Response time was in the range of 20-60 seconds depending on the concentration of the solution and the lifetime of the electrode. The electrode was linearly working at a pH of (5-10).
Most of anions were severely interfered and these were exploited to determine calcium and the anions in precipitation titrations . Cations were slightly interfered especially at high interferent concentrations .
The new electrode was applied for the determination of calcium in tap water which offered excellent results compared with flame emission photometric method .