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چکیده
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The modified electrodes containingmetalocyanoferrate constructed with several methods was used to determinaton of hydrazine and hydroxylamine. the sol-gel technique is a new simple and reliable way for the preparation of modified electrodes and solid electrolytes [1]. recently the sol-gel process coducted in the presence of graphite powder as a versatile way to obtain tailored electrode material [2]. In this work we used a teo -step sol-gel method for manufacturing f nickel hexacyanoferrate modified electrode and its catalytic activity to electrooxidation of hydrazine andhydroxylamine. The first step contains preparation of nickel powder mixed carbon ceramic composite electrode and second one is its modification with hexacyanoferate. The resulting electrode shows high sensitivity, short response time and low limit of detection in amperometric determination of hydroxyl amine and hydrazine.In comparison to former methods for preparation of modified (one step sol-gel technique) [3] this electrode (that prepared with two-step sol-gel technique) shows more reversible responses and excellent electrocatalitic activity toward hydrazine and hydroxylamine electrooxidation in the pH range of 3-9. The concentration calibration range for hydrazine 0.01-2.5 x 10-6 M amd for hydroxylamine was achieved 0.01-5x10-6 M and detection limit was < 1µM for two analytes. The kinetic parameters such as apparent electron transfer rate constant Ks), transfer coefficient α and catalitic rate costant were also determined References: 1)O.Lev; Chem. Mater; 9, 1997, 2354 2)M. Tsionsky, G. Gun, V. Glezer, O.Lev, Anal. Chem, 66, 1994, 1747 3)P. Wang, Y. Yuan, X. J.ng, G. Zhu, Talanta; 53, 2001, 863
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