Determination of Se(IV) in Pharmaceuticals by Using Different Operating Modes of Pulse Anodic Stripping Voltammetric Analysis with Methylene Blue-Nafion Modified Gold Electrode

Determination of selenium(IV) in Syrian pharmaceuticals with a methylene blue-nafion modified gold electrode by using different operating 1 modes Of pulse anodic Stripping voltammetry : with Constant amplitude of negative (PASVNP) or positive (PASVPP) polarity imposed 1 pulses of linearly increasing amplitude (PASVLIA) and differential sampling on successive pulses ((Delta I/Delta t)) was applied. Selenium(IV) was I determined in an aqueous HClO4 medium (1 M) at an accumulation potential of -240 mV and an accumulation time of 300s. The potential I was sewed from 0.0 to 1250 MV using auto scan facility. The peak Potential was Measured at 1000-1010 1030-1040; 1130,1140 and 1030-1060 mV and the calibration curve for Se(IV) under optimized Conditions was linear in the ranges 7.896-78.96, 23.688-118.44; 23.688-118.44 and 0.7896-78.96 ng mL(-1) for operating Modes PASVNP, PASVPP, PASVLIA and Delta I/Delta t, respectively. RSD was less than 5%. The Methods were applied to the determination of Se(IV)in Syrian pharmaceuticals with high sensitivity and accuracy The results I Obtained by pulse anodic stripping Voltammetry methods were validated by atomic absorption :spectroscopy with hydride generation