In this study a new hafnium selective sensor was fabricated from polyvinylchloride (PVC) matrix membrane containing neutral carrier N,AP-bis(amethyl-salicylidene)-dipropylenetriamine (Mesaldpt) as a new ionophore, sodium tetraphenyl borate (NaTPB) as anionic discriminator and djoctyl phthalate (DOP) as plasticizing solvent mediator in tetrahydrofuran solvent. The electrode exhibits Nernstian response for Hf4' (Hafnium(IV)) over a wide concentration range (2.0 x 10-7 to 1. 0 x 10` M) with the determination coefficient of 0.9966 and slope of 15.1 0.1 mV decades'. The limit of detection is 1.9 X 10-7 M. The electrode has a fast response time of 18 s and a working pH range of 4-8. The proposed membrane shows excellent discriminating ability towards Ht" ion with regard to several alkali, alkaline earth transition and heavy metal ions. It can be used over a period of 1.5 months with good reproducibility. It is successfully applied for direct determination of Ht"I in solutions by standard addition method for real sample analysis. (c) 2008 Elsevier BN. All rights reserved.