B. Narayana et al., Selective complexometric determination of copper in ores and alloys using 2,2 '-bipyridyl as masking agent, MICROCHEM J, 64(3), 2000, pp. 221-225
An EDTA titration method is described for the determination of copper(II) i
n the presence of other ions based on the selective masking ability of 2,2'
-bipyridyl. Copper and other ions in a given sample solution are initially
complexed with an excess of EDTA and the surplus EDTA is titrated with lead
nitrate solution at pH 5.0-6.0 (hexamine), using xylenol orange as an indi
cator. A known excess of 2,2'-bipyridyl solution (1% in 50% alcohol) is the
n added, the mixture is shaken well and the released EDTA from the Cu-EDTA
complex is titrated against standard lead nitrate solution. The interferenc
e of various ions are studied and the method is applied to the determinatio
n of copper in its ores and alloys. Reproducible and accurate results are o
btained for 2.54-25.40 mg of copper with S.D. values < 0.04 mg. (C) 2000 El
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