Copper(II) sensor based on a cephaloridine antibiotic PVC matrix

A poly (vinyl chloride) (PVC) based membrane of cephaloridine as a novel io nophore exhibits good potentiometric response for Cu2+ over a wide concentr ation range (10(-5)-10(-1) M) with a slope pf 28.5 mV per decade. The detec tion limit is 3.5 x 10(-6) M. The response time of the sensor is < 60 s. Th e electrode has been used for a period of one month and exhibits good selec tivity towards Cu2+, comparison to alkali, alkaline earth, transition and h eavy metal ions, with no interference caused by Pb2+, Cd2+ and Fe2+ which a re known to interfere with many other copper electrodes. The electrode can be used in the pH range from 4.0 to 6.5 and it can also be used in partiall y non-aqueous medium having up to 10% (v/v) non aqueous content and in the presence of cationic surfactants at concentrations less than 10(-3) M.