Application of Microchip Capillary Electrophoresis – Electrochemical Detection (MCE-EC) for separation and determination of Acetaminophen and Codeine

Since the initial description of the “Lab-on-a-Chip” concept, there has been an explosion of interest in the development of analytical systems utilizing the microchip format, so called micro-total analysis systems (µTAS). Microfabricated systems have numerous advantages like increased precision and accuracy, automation, reduced solvent waste, portability, high speed and disposability1. There are various materials used in the fabrication of µTAS like Glass, PDMS, PMMA, Quartz and etc2. Various detection systems like UV-Vis Spectroscopy, electrochemical, MS spectroscopy, Conductometry and etc were used in the detection systems3. These devices can be used in different fields such as environmental monitoring, biomedical and pharmaceutical analysis, clinical diagnostics, and forensic investigations4, 5.In the present study, separation and determination of Acetaminophen and codeine were investigated on the microchip capillary electrophoresis-electrochemical detection (MCE-EC). The MCE-EC device consists of SU-8/Glass and three Pt electrodes as substrates and electrochemical detection system, respectively. Dimensions of Channel were 20 (H) ×50 (W) µm with 4 and 1cm for the electromoving and side channels long, respectively. Analytes were loaded in the sample reservoir and injected to the channel by applying of appropriate voltage to the same reservoir and then the switcher applies definite voltage to the buffer reservoir. Analytes moved to the end of the channel less than one minute. It is notable that 2-(N-morpholino)ethanesulfonic acid (MES) was used as running buffer.Parameters that affected the separation and detection were investigated, including injection time and voltage, strength of separation field, detection potential, pH and concentration of running buffer. Optimized conditions were 5s, +750 V, +1000 V, +1.1 V vs. Pt reference electrode, 7 and 20 mM MES buffer, respectively. After method developing, analytical features including linearity, precision, accuracy, LOD and LOQ were studied.