18500

Trace Determination of Molybdenum by Adsorptive Catho ic Stripping Voltammetry

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Molybdenum is determined by ad orp tive cathodic stripping voltammetry in 0.15 M nitric acid solution containing 15 uM 2 י, 3,4 י ,5,7-pentahydroxytlavone (morin) as a ligan d. In this medium, molybdenum is preconcentrated on a hanging mercury drop electrode and stripped cathodically in square-wave voltammetry mode, with a peak pote ntial of -350 mV vs. Ag/AgCI (saturated KCI). The effect of various parameters (ligand concentration, supporting electrolyte composition. accumulation potential and collection time ) on the sen sitivity and line ar range of the calibration curve are di scussed. With controlled accumulation for I min, the detection limit (30) was 0.45 ng rnlי mol bdenum and the calibration curve is linear up to 70 ng mlי . The procedure is applied to the determination of molybdenum in real samples with sati sfactory result .

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