Abstrait

Mg(II) ion-selestive electrode based on chlorpohyll as ion exchanger

Adel F.Shoukry, Dhoha Al-Waheb, Rasha Al-Bashir

A novel Mg(II)-responsive electrode has been constructed based on incorporation of the naturally occurring magnesium-containing chelate, chlorophyll, in a PVCmembrane plasticized with dioctylphthalte. The sensor exhibited average slope of 31.2mV/Mg concentration decade over a concentration range of 4.0ï‚´10-5-2.8ï‚´10-2M. The performance of the electrode was not affected by the change in pH within the range 3.9-8.4. It showed high selectivity for Mg(II) over Ca(II) and the other physiological cations, Na+ and K+. However Li+ was found to interfere. X-ray photoelectron spectroscopy has been applied to examine the leaching of the active ingredients from the gel layer to the bathing solution during soaking of the electrode.