Determination of Acetaminophen in the Presence of Codeine and Ascorbic Acid at Layer by Layer MWCNT/Doped-Polypyrrole Modified Glassy Carbon Electrode

An efficient electrochemical sensor based on a layer by layer MWCNT/ doped-polypyrrole modified glassy carbon electrode was used for the determination of acetaminophen (AC) in the presence of codeine and ascorbic acid (AA). An obvious shift of the peak potential and increase of the current peak were observed for AC on the surface of PPY/MWCNT/GC in comparison to the bare glassy carbon electrode. The anodic oxidation current of acetaminophen is enhanced on the surface of PPY/MWCNT/GC electrode due to the enlarged microscopic surface area of the electrode. The results showed that two electrons and two protons participate in the nearly reversible redox reaction of AC at the modified electrode. The effect of the experimental conditions on the electrode response, such as types of dopant, pyrrole and dopant concentration, potential and number of cycles in the polymerization procedure, amount of MWCNT and pH were investigated. Under the optimized conditions, the calibration curve was obtained over two concentration ranges of 8×10-7 - 1×10-5 M and 1×10-5 - 1×10-4 M of AC in the presence of codeine with a linear correlation coefficient (R2) of 0.998 and 0.994 respectively . The detection limit (3M) was estimated to be 5×10-7 M. The developed method was successfully applied to analyze pharmaceutical preparations of AC and a recovery of 95% with a relative standard deviation of 0.98% was obtained for AC.

کلیدواژه ها:

Multi-walled carbon nanotube ، Poly-pyrrole ، hydroquinone sulfonic acid ، Acetaminophen ، Codeine