A novel modified carbon paste electrode for the determination of chromium(III) in water sample

Two kinds of modified carbon paste electrodes for chromium (III) ion based on zeolite asionophore were prepared. 3-methyl-pyrazol-5-one (MP) was used as modifier in sensor 1. Sensor1 exhibits a Nernstian response for Cr(III) ions over a wide concentration range from 1 × 10–6 to1 × 10-2 mol·L–1 with a slope of 19.8 ± 0.1 mV·decade–1.Sensor 2 was modified by usingchlorinated nanotubes. This sensor shows a Nernstian response for Cr(III) ions over aconcentration range from 1 × 10–7 to 1 × 10-2 mol·L–1 with a slope of 19.74 ± 0.1 mV·decade–1.Some parameters were optimized for two sensors such as pH of solution, composition ofmembrane and response time of electrode. And results were compared. They were successfullyapplied to direct determination of chromium (III) in water samples and as an indicator electrodein potentiometric titration of Cr(III) with EDTA.

کلیدواژه ها:

Ion selective electrode ، Functional multi-walled carbon nanotubes ، Potentiometry ، Zeolite ، 3-methyl-pyrazol-5-one