Determination of Ephedrine in urine and supplementary by modified carbon nanotubes doped by gold nanoparticles

Ephedrine and its analogous are known to have central nervous system stimulating properties [1]. Also many methods such as gas chromatography [2] and electrochemical methods [3] were carried out for the analysis of this sympathomimetic drug. In this work, an accurate, selective and rapid method using magnetic nanocomposite based on molecular imprinted polymer followed with HPLC technique was developed. In the first step, the surface of carbon nanotubes became magnetic by FeCl2 and FeCl3 in the presence of neutral gas and using ultrasonic machine. Besides to recover scattering, the surface of nanotubes were modified by functional monomer. After that, gold nanoparticles were doped on them to provide ephedrine hydrochloride molecular imprinted polymer. FT-IR and SEM were used to confirm the validation of synthesis. The temperature, pH, extraction time, kind of desorption solvent and the effect of salt were optimized. Linear calibration curves were obtained in the range of 0.1 to 200mg.ml-1 with detection limit of 0.01mg.ml-1 for each analyte and gotten extract efficiency concluded from spiked samples were 96% at the optimum pH of 7-8. This method gives acceptable results in urine and supplementary samples.