Synthesis and characterization of bis nitrato[4-hydroxyacetophenonesemicarbazone) nickel(II) complex as ionophore for thiocyanate-selective electrode.

Research paper by Sulekh S Chandra, Sunita S Hooda, Praveen Kumar PK Tomar, Amrita A Malik, Ankit A Kumar, Sakshi S Malik, Seema S Gautam

Indexed on: 10 Mar '16Published on: 10 Mar '16Published in: Materials Science and Engineering: C


The PVC based-ion selective electrode viz., bis nitrato[4-hydroxyacetophenone semicarbazone] nickel(II) as an ionophore was prepared for the determination of thiocyanate ion. The ionophore was characterized by FT-IR, UV-vis, XRD, magnetic moment and elemental analysis (CHN). On the basis of spectral studies an octahedral geometry has been assigned. The best performance was obtained with a membrane composition of 31% PVC, 63% 2-nitrophenyl octylether, 4.0% ionophore and 2.0% trioctylmethyl ammonium chloride. The electrode exhibited an excellent Nernstian response to SCN(-) ion ranging from 1.0×10(-7) to 1.0×10(-1)M with a detection limit of 8.6×10(-8)M and a slope of -59.4±0.2mV/decade over a wide pH range (1.8-10.7) with a fast response time (6s) at 25°C. The proposed electrode showed high selectivity for thiocyanate ion over a number of common inorganic and organic anions. It was successfully applied to direct determination of thiocyanate in biological (urine and saliva) samples in order to distinguish between smokers and non-smokers, environmental samples and as an indicator electrode for titration of thiocyanate ions with AgNO3 solution.