New Chemically Modified Screen-Printed Electrode for Co(II) Determination in Different Water Samples

Modified screen-printed electrode (SPE) with magnesium alumino-silicate ionophore was fabricated for the determination of Co(II). The modified electrode reveals linear response over wide concentration range of 3.1x10(-7) - 1x10(-1) mol L-1 of Co(II) at 25 degrees C with a divalent cationic slope of 30.33 +/- 0.75 mV decade(-1) and exhibit detection limit of 3.1x10(-7) mol L-1. Moreover, the selectivity coefficient was measured by matched potential and fixed interference methods. The modified SPE sensor shows high selectivity and sensitivity for determination of Co(II) and also shows stable and reproducible response over a period of four months. This method can be used for determination of Co(II) in water, soil and fish tissue samples and the results obtained agreed with those obtained with atomic absorption spectrometer (AAS). The proposed potentiometric method was validated according to the IUPAC recommendation.