Electrochemical Sensor Based on NiAlPO‐5 for Determination of Cu²⁺ in Ethanol Biofuel

Abstract

This work describes the development of electrochemical sensors based on graphite–polyurethane composite (GPU) modified with aluminophosphate zeolite type 5 (AlPO‐5) and nickel (II) incorporated aluminophosphate type 5 (NiAlPO‐5), in order to evaluate their performance for determination of Cu2+ in ethanol biofuel. These electrodes were initially characterized by cyclic voltammetry. The obtained results revealed that the NiAlPO‐5 with Ni/Al ratio 0.5 presented the best response in terms of sensitivity, and peak width at half height of Cu2+ voltamogramm, which indicate that on these conditions the NiAlPO‐5 electrode is viable for determination of this ion in biofuel samples by square wave stripping voltammetry. The obtained results revealed that the presence of Ni in the zeolite structure (NiAlPO‐5) improves the electrical properties, and increases the peak current for Cu2+ in comparison with the electrode based in AlPO‐5. The proposed method presented a linear response for Cu2+ with good results for limit of detection (9.4×10−9 mol L−1), accuracy (recovery of 115 %) and precision (RSD of 5.9 %).