Page | 982 Received: 11 July 2020 Revised: 22 August 2020 Accepted: 26 August 2020 DOI: 10.22034/ecc.2020.114589 Eurasian Chem. Commun. 2 (2020) 982-990 http:/echemcom.com FULL PAPER Selective and sensitive voltammetric sensor for methocarbamol determination by molecularly imprinted polymer modified carbon paste electrode Mahmood Payehghadr* |Yeganeh Taherkhani |Abbas Maleki |Farzaneh Nourifard Department of Chemistry, Payame Noor University, 19395-4697 Tehran, Iran *Corresponding Author: Mahmood Payehghadr Email:mahmood_payehghadr@yahoo.com Tel.: +98 09123874341 A molecularly imprinted polymer modified carbon paste electrode for determination of methocarbamol drug was constructed and used in aqueous and biological samples. The MIP was synthesized by methacrylic acid as monomer, azobis isobutyronitrile as initiator and methocarbamol as analyte with precipitation polymerization process. The oxidation voltamograms of analyte using MIP modified nickel ferrite catalyst electrode with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) by potentiostat – galvanostat device were obtained. The methocarbamol drug has amine groups in its structure, thus it is affected by the medium pH, and the effect of this factor on the electrode response was investigated. In optimum conditions, 4% MIP, 8% nanoparticles catalyst, and pH 3, 1.0×10 -5 M standard solution of methocarbamol was prepared and studied by DPV and CV mode. The dynamic calibration ranges, 3.0×10 -8 - 3.0×10 -6 M, detection limit of the method 1.3×10 -8 M and RSD of the method for two measurements 3.33% and 1.00% was obtained. KEYWORDS Carbon paste electrode; voltammetry; methocarbamol; MIP; CV; DPV. Introduction Methocarbamol (Scheme 1) is a drug with aryl glycerol ether structure that is used for muscle pain and has a calming effect [1]. This drug is absorbed through the intestine and reaches all body tissues. Due to its side effects, it is on the list of high-risk medications for the elderly. Determination of methocarbamol in biological fluids using voltammetric methods has advantages such as low cost, high sensitivity and short analysis time. Using the MIPs and nano catalysts can also increase selectivity of the method. In this method, MIPs can bond to analyte molecules and improves the electrochemical reaction condition. Drugs are important analytes in analytical chemistry, because of its effects on human health and quality control methods in manufacturers. Thus, the development of sensitive and selective, simple and rapid method for the determination of drugs is of great importance and interest. Various methods, such as high performance liquid chromatography, HPLC, [2-3], HPLC–MS [4], reverse phase liquid chromatography, RPLC, [5], supercritical fluid chromatography, SFC, [6], HNMR spectroscopy [7], derivative spectrophotometry [8] and electrochemical methods [9] have been used for determination of methocarbamol. The cost of these methods is very high. Further, because of the high