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چکیده
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In thiswork, we report a newmodified carbonpaste electrode based on silver incorporated inZSM-5nanozeolite (Ag/ZSM-5/CPE) for electrooxidation of oxalic acid (OA). ZSM-5 nanozeolite was synthesized using amorphous silica extracted from bagasse (BGA) as silica source and were characterized by the X-ray diffraction (XRD), scan-ning electron microscopy (SEM), Fourier transform infrared (FT-IR), Brunauer–Emmett–Teller (BET), Barrett-Joyner-Halenda (BJH) and energy dispersive X-ray (EDS). Accumulated spherical nanoparticles were formed with range of closely particle size of 82–163 nm. Ag/ZSM-5/CPE was used to investigate the electrocatalytic ox-idation of OA in 0.1 M PBS (pH = 2) solution by cyclic voltammetry, differential pulse voltammetry and amperometry. The current intensity of OA oxidation increases impressively on Ag/ZSM-5/CPE in the presence of OA. Additionally, amperometric studies displayed that this electrode as the sensor can detect OA in linear ranges of 16μΜ–0.18 mM and 0.18–4.0 mM with a detection limit of 5.5μM (S/N = 3). Excellent utilities of the fabricated modified electrode such as low detection limit, wide linear range of concentration and high sensi-tivity make it as good sensor for the selective determination of OA. Ag/ZSM-5/CPE was used for OA detection in real samples such as spinach and cabbage. Possible interferences such as ascorbic acid, tyrosine, uric acid, ethyl-ene glycol, glyoxylic acid and dimethyl oxalate for the detection of OA at the Ag/ZSM-5/CPE were studied. The results exhibits that these compounds do not show any interference on OA measurement.
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