Synthesis of a New PVC membrane selective electrode for the Determination of Lanthanum(III)Based on Paraldyhed phenyl hedrazon as an Electroactive Metarial

In this study, a new poly(vinyl chloride) (PVC) membrane electrode for La3+ ion based on paraldyhed phenyl hedrazon as an electroactive material was prepared.This electrode revealed good selectivity for La3+ over a wide variety of other metal ions. Effects of experimental parameters such as membrane composition, nature and the amount of plasticizer, the amount of additive on the potential response of La3+ electrode were investigated. The electrode exhibited a Nernstian slope of 20.0±1.0mV per decade of La3+ over a concentration range of 1×10-7 to 1×10-1M of La3+ in the pH range 3.8–8.0. The response time was about 30 s and the detection limit was 7×10-8 M. The electrode couldbe used for at least one month without a considerable divergence in potential. The proposed electrode was used for the determination of lanthanum in a standard solations andwas successfully applied as an indicator electrode for potentiometric titration of La3+ with EDTA.

Ion-Selective Electorde for Copper (II) Determination Based on Copolymer Anhydirde Maleic-Vinyle Acetate

Ion selective electrode of Cu٢+ for determining of copper (II) in acid and Ammonia Solutions is presented. Optimal conditions and main characteristics of such electrode have been determined. The effect of anionic surfactants on the electrode has been investigated. The use of protective film such as cellophane, cellulose acetate, Lavsan, or nitro cellulose could be possible in order to avoid the difficulties related to the work in surfactant presented in the solutions.