Determination of benorilate in pharmaceutical formulations and its metabolite in urine at carbon paste electrode modified by silver nanoparticles

Benorilate was determined by the differential pulse voltammetry (DPV) using a carbon paste electrode modified by silver nanoparticles in 1.25 x 10(-3) mol 1(-1) KH2PO4 and Na2HPO4 buffer solution (pH = 6.88, 25 degrees C). The anodic peak potential was +0.970 V (versus SCE). A good linear relationship was realized between the anodic peak currents and benorilate concentrations in the range of 1.0 x 10(-7) to 2.5 x 10(-4) Mol 1(-1) with the detection limit of 1.0 x 10(-8) mol 1(-1). The recovery was 95.2-103.6% with the relative standard deviation of 3.6% (n = 9). The pharmaceutical preparations, benorilate tablets samples and its metabolite (salicylic acid) in urine were determined with the desirable results. (c) 2005 Elsevier B.V. All rights reserved.