Water I.D. Primelab 2.0, Manual

Page: 118 / 301

For the analysis of total copper the following procedure is necessary:i) Add concentrated
sulfuric acid to the test sample (1 ml per 100 ml of test sample). By boiling it for 10 minutes,
everything is dissolved. Now cool down the test sample. Then add ammonia and bring the
sample to a pH value of 3 – 5. The initial volume of 100 ml of fluid has to be filled up with
deionized water. The analysis can now be performed as described with 10 ml of the liquid
obtained.ii) With organic compounds pretreated water may need to be oxidized (destruction of
the copper complexes). Add concentrated sulfuric acid and concentrated nitric acid to the test
sample (1 ml per 100ml each). Now cool the test sample. The analysis can now be performed
as described.
For the analysis the water has to have a pH value of 4 - 6. Strongly acidic water having a pH
value of <2 should be neutralized with 8 mol/l potassium hydroxide.
Not yet completely dissolved powder has no effect on the accuracy of the measurement.
Disorders: i) Cyanides (CN⁻): To ensure full color development, the test sample has to be
enriched with 0.2 ml of formaldehyde and wait 4 minutes. The analysis can now be performed
as described. The test result must be multiplied by 1.02.ii) Silver (Ag⁺): Silver can cause
blackening of the test sample. Add saturated potassium chloride solution (10 drops per 75 ml).
Then the test sample had to be poured through a fine filter. The analysis is now carried out as
described with 10 ml of the filtered liquid.
T63/204 T63/204