VISOCOLOR® HE Copper • Colorimetric determination of copper • In weakly alkaline medium copper(II) ions react with cuprizone forming a blue colour complex. • Strongly acidic and buffered solutions have to be adjusted to pH 9 with ammonia for the test. • Iron(II), chromium(VI), nickel and manganese ions interfere in concentrations above 10 mg/l. • Cr(III) concentrations which exceed the copper concentration cause low results, but can be eliminated by oxidation to chromate using ammonium peroxodisulphate / sulphuric acid). • Cobalt ions form a red colour complex which, depending on the copper concentration, can already interfere above 1 mg/l. Cyanides and sulphides present in excess of 1 mg/l cause low results. • Type: high sensitive test kit • Range: 0.0 · 0.04 · 0.07 · 0.10 · 0.15 · 0.20 · 0.25 · 0.30 · 0.40 · 0.50 mg/l Cu2+ • Sufficient for: 100 determinations • Shelf life at least: 24 months • Sea water suitability: yes • Detectable with PF-11: no • In water copper(II) can be found in dissolved as well as in undissolved form. • Copper(I) compounds and undissolved copper(II) compounds are not determined unless they are decomposed with concentrated nitric acid prior to the test.