Novel Beryllium Membrane Sensor Based on 2,4-Dinitrophenylhydrazinebenzo-9-crown-3 Coated Graphite

Abstract

A novel sensor based on 2,4-dinitrophenylhydrazinebenzo-9-crown-3 (NPHC) for selective determination of ultra trace amount of beryllium is reported. The plasticized PVC membrane containing 30% PVC, 58% ortho-nitrophenyloctyl ether (NPOE), 3% sodium tetra phenyl borate (NaTPB) and 9% NPHC was directly coated on a graphite electrode works well over a wide range of concentration (1.0 × 10⁻¹ to 4.0 × 10⁻⁷ M) with a Nernstian slope of 29.5 mV per decade. The electrode shows a fast response time of 10 s and operates in the pH range 3.0–9.0. The sensor can be used for more than five months without any divergence in the potential. The selectivity of the electrode was studied and it was found that the electrode exhibits very good selectivity for beryllium ion over alkali, alkaline earth, heavy, and transition metal ions. The beryllium ion-selective electrode was used as an indicator electrode for the potentiometric titration of beryllium ion in solution using a standard solution of EDTA, a sharp potential change occurs at the end-point. The applicability of the sensor to Be(II) ion measurement in water samples spiked with beryllium chloride is illustrated.

Keywords:

• Sensor
• Beryllium
• Beryllium-selective electrode
• 2,4-Dinitrophenylhydrazin benzo-9-crown-3