Determination of Salicylate by Selective and Sensitive Polymer Membrane Electrode: with Internal Solution and Solid Contact

In this work we developed a new salicylate-selective membrane based on thetrioctylmethyl ammonium chloride as the ion exchanger. the treatment of membraneinvestigated and compared in two different types. in one type membrane put on the pvc tube,electrode with internal solution (is), and in another type membrane glued on a glassy carbonelectrode, solid contact electrode (sc). both sensors show a nernstian response (56±1.0 and57.7±1.0 mv decade-1, respectively) to salicylate ions over a very wide concentration ranges(3×10-6?1 m and 1×10-6?1 m, respectively). the detection limits of these sensors are 1×10-6and 8×10-7 m, respectively. the electrodes possess satisfactory reproducibility, very shortresponse time (~ 5 s) in the whole concentration ranges, and discriminating ability forsalicylate ions with respect to the most common inorganic anions and special organic andbiological anions. the selectivity coefficients, linear range and detection limit were better formembrane that glued on glassy carbon electrode. two electrodes could be used in ph rang 5.0to 12.0. the electrodes were successfully used for determination of salicylate in real samples.