Paragraph 3 REAGENTS

3.1

Hydrochloric acid (density at 20°C ρ = 1.18 g/ml).

3.2

Hydrochloric acid, 6 M solution.

3.3

Hydrochloric acid, 0.5 M solution.

3.4

Ammonium nitrate.

3.5

Hydrogen peroxide, 30%.

3.6

Copper solution^f1 (stock): weigh, to the nearest 0.001 gram, 1 gram of pure copper, dissolve in 25 ml of 6 M hydrochloric acid solution (3.2), add 5 ml of hydrogen peroxide (3.5) in portions and dilute to 1 litre with water. 1 ml of this solution contains 1,000 μg of copper (Cu).

3.6.1

Copper solution (dilute): dilute 10 ml of stock solution (3.6) to 100 ml with water and then dilute 10 ml of the resulting solution to 100 ml with water. 1 ml of the final dilution contains 10 μg of copper (Cu).

Prepare this solution at the time of use.

Annotations

Footnotes

f1: Commercially available standard copper solution may be used.