A new cerium (III)-selective membrane electrode based on 2-aminobenzothiazole

A new poly(vinyl chloride) (PVC) membrane electrode based on 2-aminobenzothiazole and oleic acid (OA) as a good lipophilic additive for highly selective determination of Ce3+ ion has been developed. The electrode exhibits a Nernstian slope of 19.6 +/- 1.0 mV per decade over wide Ce3+ ion concentration range from 2.0 x 10(-6) to 2.0 x 10(-2) M and low detection limit 1.8 x 10(-6) M. The electrode possesses a fast response time of similar to13 s, relatively long lifetime (at least 3 month). The proposed electrode revealed excellent selectivity for Ce3+ over a wide variety of alkali, alkaline earth, some transitions, and heavy metal ions. The electrode could be used in a pH range of 4.1-7.3. The practical utility of the electrode has been demonstrated by its usage as an indicator electrode in potentiometric titration of oxalate (C2O42-) and fluoride (F-) ions with Ce3+ solution. The proposed electrode was also successfully applied to the determination of F- ion in mouthwash solution. (C) 2003 Elsevier B.V. All rights reserved.