Tin(II)-selective membrane potentiometric sensor using a crown ether as neutral carrier

A PVC membrane Sn(II)-ion-selective electrode has been constructed using dibenzo-18-crown-6(DB18C6) as membrane carrier. The sensor shows a near Nernstian response for Sn(H) ions over a concentration range from 1.0 x 10(-6) to 1.0 x 10(2) M with a slope of 27.5 +/- 0.6mV per concentration decade in an acidic solution (pH = 1). The limit of detection was 8.0 x 10(-7) M. It has a response time of < 15s and can be used for at least 3 months without any divergence in potentials. The proposed membrane electrode revealed very good selectivity for Sn(II) ions over a wide variety of other cations and could be used in acidic media. The isothermal temperature coefficient of this electrode amounted to 0.0012 V/C. The stability constant (log K-s) of the Sn(II)-DB18C6 complex was determined at 25 C by potentiometric titration in mixed aqueous solution. It was used as indicator electrode in potentiometric determination of Sn(II) ion in real sample, (c) 2004 Elsevier B.V. All rights reserved.