Amperometric determination of sympathomimetic drugs by flow injection analysis with a metallic copper electrode Original Research Article

The detection and determination of sympathomimetic drugs in flow injection systems with an amperometric method based on a metallic copper wire electrode is described. The copper electrode is shown to give sensitive response toward sympathomimetic drugs, especially for norephedrine in flow injection analysis. The copper electrodes require no pretreatment except polishing before use. Furthermore, the copper working electrode shows stable response in such a system and the relative standard deviation is only 4.6% for 30 consecutive norephedrine injections at a 0.15 mM level. A detection limit of 10−9 mol (0.15 μg norephedrine) for a sample loop of 0.1 ml was obtained at a fixed potential of +0.6 V (vs. Ag/AgCl) in NaOH 0.1 M and a flow rate of 2.0 ml/min.