Development of electrochemical determination of dextromethorphan

Abstract

This thesis focuses on developing a simple and effective disposable electrode for detecting dextromethorphan (DEX) in pharmaceutical and forensic samples. Laser ablation at the optimal condition of power and speed produced a laser-induced nitrogen doped graphene electrode (LING) in a single laser fabrication. Scanning electron microscopy, energy dispersive X-ray, Raman spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the morphology of fabricated materials. The electrochemical characterization of electrodes was studied using cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical behavior of DEX was investigated using cyclic voltammetry and analytical measurements were performed using differential pulse voltammetry. Differential pulse voltammetry was optimized in terms of potential pulse, time pulse, potential step, scan rate, deposition potential, and deposition time. In the optimal condition, two linear ranges were observed, ranging from 2.5 to 25 �mol L?1 and 25 to 400 �mol L?1. The limit of detection (LOD) was 1.8 �mol L?1. The developed method produced a statistically significant agreement with high-performance liquid chromatography for the determination of DEX in pharmaceutical and synthetic forensic samples.????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????????? (laser-induced nitrogen doped graphene electrode, LING) ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????????? ????????????????????????????????????????????????? ??????????????????????????????????????????? ????????????????????????????? ????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????????? ????????????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????? ?????? ??????????????? ????????? ?????????????? ???????????? ?????????????? ??????????? ?????????????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????? ?????? 2.5 ??? 25 ??????????? ??? 25 ??? 400 ??????????? ?????????????????????????????? 1.8 ??????????? ??????????????????????????????????????????????????????????????????????????????????? ?????????????????????????????????????????????????????????????????????????????????????????????????????????????