| Popis: |
The differential pulse polarographic determination of molybdenum in nitrate media is described. The effects of pH, nitrate concentration, temperature, and cationic and anionic interferents on the peak current are reported. The detection limit is 0.45 μg l -1 for a single scan. Signal averaging can be used to achieve a detection limit of 0.2 μg l -1 , and a linear calibration graph over three orders of magnitude. The kinetics and mechanism of the catalytic current are discussed within the framework of a series of equations which describe the relationship between peak current, pulse height, time of measurement and concentration of both analyte and background electrolyte. The key species appears to be electrochemically generated Mo(IV) which is oxidized to Mo(V) by nitrate. |
