Browsing by Author "Alemu, Yazachew"

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    Simultaneous Determination of Catechol and Hydroquinone at Poly-P-(Asa)/Mwcnt Compsite Modified Glassy Carbon Electrode
    (Addis Ababa Universty, 2010-06) Alemu, Yazachew; Tessema, Merid (PhD)
    A simple and highly selective electrochemical method for simultaneous determination of hydroquinone and catechol has been developed at a glassy carbon electrode modified with multiwalled carbon nanotubes (MWCNT) and poly-para-amidosalicyclic acid (poly-p-ASA). It was found that the oxidation peak potential separation and the oxidation currents of hydroquinone and catechol highly increase at the polymer and MWCNT modified glassy carbon electrode in 0.10 M phosphate buffer solution (pH 7.0). The oxidation peak potential of hydroquinone and catechol merge into a large peak at 430.71 mV at bare glassy carbon electrode. The two well-defined oxidation peaks of hydroquinone in the presence of catechol at poly-p-(ASA), MWCNT and composite modified electrode occur at 136.52 mV and 228.04 mV, 161.29 mV and 262.82 mV and 172.12 mV and 286.85 mV respectively. Under the optimized condition, the oxidation peak current of hydroquinone is linear over a range from 2.0×10-5 M to 7.0×10-4 M hydroquinone in the presence of 1.0×10-3 M catechol with the detection limit of 1.2×10-6 M and the oxidation peak current of catechol is linear over a range from 2.0×10-5 M to 6.0×10-4 M catechol in the presence of 1.0×10-3 M hydroquinone with the detection limit of 1.4 ×10-7 M. The proposed method has been applied to the simultaneous determination of hydroquinone and catechol in a water sample and the results are satisfactory. KEYWORDS Electrochemistry, Electropolymerization, Multiwalled carbon Nanotubes, chemically modified electrode, Hydroquinone, Catechol and para-amidosalicyclic acid