A Novel Potentiometric Membrane Sensor for Quick Determination of Trace Amount of Based on a Zinc–Schiff 's Base

Abstract

Poly(vinylchloride) (PVC) based membrane of Zinc–Schiff 's base (ZSB) with hexadecyltrimethyl ammonium bromide (HTAB), hexadecylpyridinum bromide (HDPB) as cation excluders and dibutyl phthalate (DBP) and benzyl acetate (BA) as plasticizing solvent mediators were prepared and investigated as -selective electrode. The best performance was observed with the membrane having the composition ZSB–PVC–HTAB–BA in the ratio 5%: 32%:3%:60%, which works well over a wide concentration range (1.0 × 10−2 to 1.0 × 10−6 M) with a Nernstian slope of −29.2 mV per decade of activity between pH 2.0 and 7.0. This sensor shows a very fast response time of 10 s and was used over a period of two months with good reproducibility. The proposed sensor displays an excellent selectivity for over a large number of common inorganic anions. The sensor has been successfully applied for determination of iron in ferrous sulfate syrups, and as indicator electrode in the potentiometric titration of sulfate ions with barium ions, and vice versa.