An Imidazol Based Novel Potentiometric PVC Membrane Sensor for Aluminium(III) Determination

A new aluminum-selective liquid membrane electrode based on a neutral carrier 2-(4,5-dihydro-1,3-imidazol-2-yl)phenol(L) in a poly(vinyl chloride) (PVC) matrix is described. The sensor exhibits a Nernstian response for Al(III) over a wide concentration range (1x10(-6) M - 1x10(-1) M) and detection limit of (7x10(-7) M). The best performance was obtained with a membrane composition of PVC (33%), ortho-nitrophenyloctyl ether (o-NPOE)(64%), ionophore (L) (2%) and sodium teraphenyl borate (NaTPB)(1%). The sensor exhibits the advantages of fast response time (10 seconds), operational lifetime (120 days), mixed solvent media tolerance upto (20%) and good selectivity co-efficient for Al(III) over an alkali, alkaline earth and transition metal ions. The electrode was used as indicator electrode in potentiometric titration of Al(III) with ethylenediaminetetraacetic acid ( EDTA).