POTENTIOMETRIC RESPONSE PROPERTIES OF SENSOR MEMBRANES BASED ON COBALT PHTHALOCYANINE CONJUGATE-POLYMER IN NONAQUEOUS SOLUTIONS

Some experiments are carried out in order to clarify the reason why th e electrode prepared by coating a platinum disk with a non-plasticized membrane of polyacrylaminde polymer (PAA) coupled to cobalt phthalocy anine (CoPc) shows such a Nernstian response and a special selectivity for fluoride and cyanide ions in acetonitrile (AN). Special interacti ons between the ions and CoPc are observed spectrophotometrically. A c omplexing ability of the CoPc with only fluoride and cyanide ions work s to respond in a Nernstian way for the ions at the electrode. Since t he electrode shows quite poor response to chloride and bromide ions it can be understood that an ion exchange reaction of the ions in the so lution at CoPc does not function to the response of the electrode. Fur thermore, the PAA matrix of the membrane is found to produce the elect rochemical masking effect on chloride and bromide ions. The PAA-CoPc e lectrode is confirmed as available for use of determining the solubili ty product constant of sodium fluoride in AN.