Polarographic determination of oxamide in the presence of copper(II) and chromium(VI)

Abstract

A polarographic method for the determination of oxamide at the parts per million level is demonstrated. Both carbonate and ammonium tartrate buffers are suitable, but only the latter permits the determination of oxamide in the presence of similar levels of copper(II) and chromium(VI) species. At higher chromium(VI) levels, there is significant overlap by the chromium(VI) on the oxamide polarographic peak. A successful method for the removal of chromium(VI) was established by precipitation with barium(II). This permits the determination of oxamide from solutions containing a 100-fold excess of chromium(VI). A large excess of copper(II) did not affect the oxamide peak.