A Cadmium Ion-selective Membrane Electrode Based on Strong Acidic Organic-inorganic Composite Cation-exchanger: Polyaniline Ce(IV) Molybdate

• Main Authors: Syed Ashfaq NABI, Zafar ALAM, Inamuddin
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2008-05-01
• Series: Sensors & Transducers
• Subjects: Composite cation-exchanger; polyaniline Ce(IV) molybdate; Cd(II) ion-selective membrane electrode
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/may_08/P_277.pdf

A cadmium ion-selective composite cation-exchanger polyaniline Ce(IV) molybdate was used as electroactive component for the construction of a ion-selective membrane electrode. The membrane electrode showed a Nerstian response for Cd(II) ions over a wide concentration range 5 × 10-6 – 1 × 10-1 with a sub-Nerstian slope of 27 mV per decade change in concentration of cadmium ions. The limit of detection was also ascertained to be 5 × 10-6 M. It has a fast response time 15 s and can be very well utilized for more than three months with out any appreciable divergence in potentials. The optimum pH for the smooth functioning of this electrode was found to be in the Ph range of 2.5 – 7.5. The electrode also showed better selectivity for Cd(II) ions over many other interfering ions. The practical utility of membrane electrode was demonstrated by using as indicator electrode for the potentiometric titration of Cd(II) with EDTA and determination of cadmium content in drain water.