potentiometric determination of vancomyin using ion- selective electrode

in this study‚ potentiometric determination of small amounts of vancomycin hydrochloride using ion-selective membrane electrode has been investigated. design and preparation of electrode is based on pvc membrane‚vancomycin- phosphomolibdic ion pair as the sensing element‚ dbp as plasticizer and thf as solvent. the electrode exhibits a nernestian response with a slope of about 56.02 mv in concentration range of 10^-5 -10^-2 m in ph range of 4-6. the low detection limit of the electrode is about 3×10^-5 and the response time of about 15 s. the proposed electrode was used for at least 4 weeks without any measurable change in sensitivity. no interference was observed towards some inorganic ions and also some drugs. the electrode was successfully employed for the measurement of vancomycin-hydrochloride in the form of vial purchased from the local pharmacy and good recovery about %97 was obtained. with regards to the simplicity‚speed‚ accuracy‚ sensitivity‚ selectivity and good recovery this electrode can be used as a convenient and reliable tool for quantitative analysis of vancomycin.