Potentiometric Determination of HPO42- with Chitosan- Cu by Carbon Paste Electrode

In the present work, using modified copper chitosan, HPO42- anion is measured by potentiometric method. A room temperature ionic liquid, 3-methyl-imidazoliumtetrafluoroborate and paraffin for compare of conductive effect are used. Response time, pH range, electrode selectivity, electrode life have been investigated. Carbonnanotubes (WCNTs) were used in the composition of the carbon paste to improve conductivity and transduction of chemical signal to electrical signal. Also, the effect ofdifferent carbon nanotubes (single-wall carbon nanotubes, multi-wall carbon nanotubes and COOH functionalized single-wall carbon nanotubes, COOH functionalized multi-wall carbon nanotubes and NH2 functionalized single-wall carbon nanotubes and NH2 functionalized multi-wall carbon nanotubes) on the electrode s response has been investigated. The electrode has a short response time (∼5 s) and can be used for at least 50 days without any considerable divergence in potentials, and the working pH range was 6.9–8.3. fabricated sensor for determining of HPO42- demonstrated a maximum Nernstian slope equal to 29.2 mVdecade-1 along a linear range from 1×10−6 to 1×10−2 mol.L−1 and detection limit of 4.35×10−7 mol.L-1. Finally, the proposed electrode was successfully used as an indicator for potentiometric determination of HPO42- in Hydroponic farm wastewater samples.