Determination of Salicylate ion by Potentiometric Membrane Electrode based on Zinc Aluminium Layered Double Hydroxides-4(2,4-dichlorophenoxy)Butyrate Nanocomposites

摘要

A new salicylate ion sensor based on zinc aluminium layered double hydroxides-4(2,4- dichlorophenoxy) butyrate (Zn/Al-DPBA) nanocomposite was developed. Three plasticisers withdifferent polarity, namely 2-nitrophenyloctylether (2-NPOE), tris(2-ethylhexyl) phosphate (TEHP) andbis(2-ethylhexyl) adipate (BEHA) were used to study the performance characteristic of the sensor. Themembrane electrode having compositions 7:30:60:3 (Zn/Al-DPBA:PVC: 2-NPOE:NaTPB)-5 exhibited excellent Nernstian slope of 58.8 1.0 mV/decade in the concentration range of 1.0 x 10 to-1 -6 1.0 x 10 M. It had a detection limit of 3.9 x 10 M and was able to give a constant potential responsein the pH range of 4.0 to 12.0 at 25 1 C. The proposed sensor was easy to develop, low cost, showedfast response time (within 11-35 s) and can be used up to 4 months without any divergence inpotential. The electrode was used for the determination of salicylate in pharmaceutical samples and theresults were comparable with those obtained with high performance liquid chromatography method.