Simultaneous determination of trace amounts of iron and copper by square-wave polarography
1964 Volume 13 Issue 2 Pages 117-122
Details
1964 Volume 13 Issue 2 Pages 117-122
Various supporting electrolytes have been tested for simultaneous square-wave polarographic determination of trace amounts of iron and copper in highly pure substances.
Oxalic acid solution containing a small amount of sulfuric acid was found to be suitable and its fundamental studies were carried out. The peak of iron appeared at -0.21 V (vs. Hg pool) in a solution containing 0.3M oxalic acid and 0.1M sulfuric acid, and that of copper at -0.35 V (vs. Hg pool).
Calibration lines were linear in the range of 5×10-65×10-5M for iron and 1×10-61×10-5M for copper. Although 30 times as much iron than copper had no disturbing influence, the amount of copper must not exceed 4 times of iron.
Several ppm of iron and 1 ppm of copper in a reagent grade arsenous acid were accurately determined by extracting them preliminarily with sodium diethyldithiocarbamate.
