Comparative Voltammetric Behavior and Determination of Mephenesin in Pure Form, Pharmaceuticals and Biological Fluids at Pencil Graphite and Glassy Carbon Electrodes

New voltammetric methods are introduced for the determination of a skeletal muscle relaxant namely; mephenesin (Mep) in its pure form with the application in the pharmaceutical preparation and biological fluids. Three voltammetric methods namely; cyclic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV) using pencil graphite electrode (PGE) and glassy carbon electrode (GCE) were used. Voltammetric behavior of Mep was investigated in Britton Robinson (BR) buffer as electrolyte in pH range 2-10. CV produced one irreversible anodic peak revealing oxidation reaction in pH 6 as maximum pH value at 1.33 and 1.36 V using PGE and GCE, respectively. At PGE, DPV and SWV were investigated and linearity ranges were 18.02-119.07 and 18.02-70.0 µg/mL with correlation coefficient 0.9997 and 0.9995, LOD values were found to be 0.113 and 0.059 µg/mL, respectively. At GCE, linearity ranges were 9.05-44.39 and 4.54-65.78 µg/mL with correlation coefficient 0.9996 and 0.9999, LOD values were 0.553 and 0.865 µg/mL at DPV and SWV, respectively. The proposed methods were applied with good recovery in pharmaceutical preparation, human mother milk and urine. They were validated and revealed accurate and precise results.