Poly (4-Amino-3-Hydroxynaphthalene Sulfonic Acid)-Modified Glassy Carbon Electrode for Electrochemical Detection of Ephedrine in Human Urine

A polymer modified glassy carbon electrode was fabricated byelectropolymerizing 4-amino-3-hydroxynaphthalene sulfonic acid (ahnsa) in a 0.1 mhno3 and was characterized by cyclic voltammetry. the polymer modified electrodeshowed an excellent electrocatalytic activity towards the electrochemical oxidation ofephedrine. the oxidative peak current response of ephedrine at the polymer modified-glassycarbon electrode was found to show linear dependence on the concentration of ephedrine inthe range of 8.0×10-6 to 1.0×10-3 mol l-1 with a linear regression equation, correlationcoefficient and limit of detection (according to s/n=3; for n=4) of ipa(?a)=0.971+0.042 c(?m), 0.99913 and 7.9×10-7 m, respectively. the proposed method was tested for thedetermination of ephedrine in human urine. recoveries ranging between 92.06–93.15% forfiltered and 81.15–86.30% for unfiltered human urine were achieved validating thedeveloped method.