Aluminium(III)-selective electrode based on a newly synthesized tetradentate Schiff base

A PVC membrane electrode for aluminium ion based on bis(5-phenyl azo salicylaldehyde) 2,3-naphthalene diimine (5PHAZOSALNPHN) as an ion carrier was developed. The electrode exhibits a Nernstian slope of 19.3±0.8 mV per decade and a linear range of 5.0×10−6–1.0×10−2 M for Al(NO3)3. The limit of detection is 2.5×10−6 M. It has a fast response time of about 10 s and can be used for at least 10 weeks without observing any deviation. The proposed membrane sensor revealed good selectivity for Al3+ over a wide variety of other metal ions and could be used in pH range of 2.9–5.0. It was used as an indicator electrode in potentiometric titration of aluminium ion.