A disposable graphite paper electrode was fabricated by a screen-printing technique,which had such advantages as low cost,no polish and good reproducibility.A simple and rapid electroanalytical assay for the determination of nitrate at an in situ copper-modified graphite electrode was proposed on the basis of differential pulse voltammetry by using a home-made portable electrochemical analyzer.The in situ copper-modi ed graphite paper electrode has greatly improved the analytical sensitivity of nitrate than the modified glassy carbon electrode.The nitrate differential pulse voltammetry response increases linearly with nitrate concentration over a range of 0.03-1mmol/L,and the detection limit is 1.084 μmol/L.In addition,the interferential effects of some common anions in water samples on the nitrate determination were investigated,which indicated that the electrode in this paper had good selectivity to NO3-.The disposable graphite paper electrode can also be effectively applied to the determination of nitrate in natural water.%为了简单快速测定硝酸根,通过丝网印刷技术制作出了低成本、免打磨和重现性良好的石墨纸电极,在自制便携式电化学分析仪上,采用差分脉冲伏安法同位镀铜催化还原硝酸根.与铜修饰的玻碳电极相比,铜修饰的一次性石墨纸电极大大提高了硝酸根的分析灵敏度.在硝酸根离子浓度为0.03～1 mmol/L范围内,硝酸根离子的浓度与还原峰电流呈良好的线性关系,检出限为1.1 μmol/L.此外,研究了水样中一些常见阴离子对硝酸根测定的干扰作用,电极表现出较好的抗干扰性.此电极能有效地应用于实际水样中硝酸根的检测.
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