In the present paper, the use of a carbon paste electrode modified by 2,2'-[1,2 buthanediylbis (nitriloethylidyne)]-bis-hydroquinone (BH) and TiO2 nanoparticles prepared by a simple and rapid method was described. The modified electrode showed an excellent character for electrocatalytic oxidization of norepinephrine (NE), acetaminophene (AC) and folic acid (FA). Using differential pulse voltammeny (DPV), a highly selective and simultaneous determination of NE, AC and FA has been explored at the modified electrode. Differential pulse voltammetry (DPV) peak currents of NE, AC and FA increased linearly with their concentration at the ranges of 4.0-1100.0 mu M, 12.5-500.0 mu M and 200.0-3200.0 mu M, respectively and the detection limits for NE, AC and FA were 0.5 mu M, 2.6 mu M and 25.0 mu M, respectively. (C) 2010 Published by Elsevier B.V.