Determination of traces of copper in cement by solvent extraction and spectrophotometric method
Determination of trace elements in cement. IV
1966 Volume 15 Issue 8 Pages 825-829
Details
1966 Volume 15 Issue 8 Pages 825-829
Traces of copper in cement were determined by solvent extraction and spectrophotometric method. The procedure established is as follows. A sample is dissolved in hydrochloric acid with ammonium chloride, and silica, being made insoluble, is filtered off. Copper in the filtrate is reduced to Cu(I) with hydroxylamine hydrochloride, and then is extracted at about pH 5.5 into iso-amyl alcohol as copper-2, 2'-biquinoline complex, which shows maximum absorbance at 550 mμ. In this case, tartaric acid has been added to prevent ferric iron and aluminum from precipitating into hydroxides.
Copper-2, 2'-biquinoline complex is completely extracted at pH 4.56.5 under the conditions proposed, and is stable at least for two hours.
As little as 0.001% copper in cement was determined with satisfactory results, which showed the presence of 0.0020.01% of copper in commercial products.
