A fast response hafnium selective polymeric membrane electrode based on N,N′-bis(α-methyl-salicylidene)-dipropylenetriamine as a neutral carrier

In this study a new hafnium selective sensor was fabricated from polyvinylchloride (PVC) matrix membrane containing neutral carrier N,N′-bis(α-methyl-salicylidene)-dipropylenetriamine (Mesaldpt) as a new ionophore, sodium tetraphenyl borate (NaTPB) as anionic discriminator and dioctyl 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 × 10−7 to 1.0 × 10−1 M) with the determination coefficient of 0.9966 and slope of 15.1 ± 0.1 mV decades−1. The limit of detection is 1.9 × 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 Hf4+ 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 Hf4+ in solutions by standard addition method for real sample analysis.