engleski

Application of Nitrilotriacetic Acid Modified Gold Electrode for Determination of Lead in Natural Waters with Differential Pulse Adsorptive Cathodic Stripping Voltammetry

A self assembled monolayer (SAM) of cysteamine (CA) was prepared on the surface of gold disc electrode and further modified with nitrilotriacetic acid (NTA). Characterization of prepared Au/CA/NTA electrode was done with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in the presence of potassium hexacyanoferrate(II)/(III). Thus prepared electrode was tested for determination of lead. The binding of Pb2+ onto the modified electrode was successfully performed in the wide range of tested concentrations. The response of modified electrode to Pb2+ concentration was measured by adsorptive cathodic stripping voltammetry. Under the optimized working conditions (accumulation time, pH for lead accumulation and stripping) the dependence of the stripping peak current response on concentration of Pb2+ was linear in the range of 0.002 – 10 µM with a correlation coefficient of 0.9839. The interference of Co2+, Ni2+ Mg2+, Mn2+ and Ca2+ was significantly reduced in borate buffer pH = 7. Lead determination in potable and thermal water samples confirmed practical application of prepared sensor.

gold electrode; cysteamine; nitrilotriacetic acid; self assembled monolayer; lead; adsorptive cathodic stripping voltammetry

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