polymeric membrane sensor for potentiometric determination of tin(ii) ions

tin(ii)-ion-selective electrode consisting of dibenzo-18-crown-6 (db18c6) as an ionophore inpvc matrix was developed. the influences of membrane composition, selectivity, response time,reversibility and temperature on the electrode performance were investigated. the electrodeshowed a near nernstian response for sn2+ ions over a concentration range from 1.0× 10-6 – 1.0× 10-2 m with a slope of 27.5 ± 0.6 mv per concentration decade in a acidic solution (ph=1). thelimit of detection was 8.0 × 10-7 m. it has a relatively fast response time and can be used for atleast 3 months without any divergence in potentials. the isothermal temperature coefficient of thiselectrode amounted to 0.0012 v/ °c. the stability constant (log ks) of the sn(ii) – db18c6complex was determined at 25 °c by potentiometric titration in mixed aqueous solution.