Precise Coulometric Determination of Hg in High-Temperature Superconductors Hg-Ba-Cu-O at a Constant Potential

摘要

A method of coulometric determination of 6 - 30 mg of Hg(II) in a supporting electrolyte (0.1 M HNO_3) at a constant potential (0.2 V) in the presence of 14-fold molar excess of copper and 6-fold molar excess of Ba on a TMP-4 working electrode. The method is developed with allowance for the effect of Cu(II) ions on the results of determination and then tested on model solutions (the determination error is no more than 0.2 percent, S_r = 0.001) and HTSC samples of the composition Hg-Ba-Cu-O (S_r is no more than 0.002).