Copper
Precise rapid tests for water and waste water samples
Copper is, like silver and gold, a coinage metal. The corrosion resistance of the three metals was recognized early, which is why they have been used for production of coins. In nature, copper is found genuine in smaller quantities, but also in compounds such as carbonates, oxides or sulfides.
Copper(II) ions may be present in water in dissolved as well as in insoluble form. In natural waters and municipal wastewaters, copper is normally found only at very low concentrations. In industrial effluents, however, it may be present at significantly higher concentrations, e.g. in metal processing plants, in the electroplating industry and in seepages from waste dumps.
In industry, copper is one of the most commonly used metals. Copper metal is characterized by excellent electrical conductivity, oxidation resistance and thermal conductivity. In addition, it is used in the form of its alloys, such as brass and bronze. Copper has antiseptic effects like silver.
Copper is used, amongst other things, in electroplating plants. Here, the concentration is monitored regularly. It has also been used for water pipes. Depending on the pH value, copper can be detected in drinking water.
Our Copper Products
| Product | Range | REF | Order | |||||
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| Cuprotesmo | > 5 mg/L Cu+/2+ or > 0.05 µg Cu | 90601 |
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| NANOCOLOR® Copper 5 | 0.10 - 7.00 mg/L Cu2+ | 985053 |
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| QUANTOFIX® Copper | 0 · 10 · 30 · 100 · 300 mg/L Cu+/2+ | 91304 |
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| QUANTOFIX® Copper Sensitive 5 | 0 · 0.1 · 0.5 · 1.0 · 2.0 · 5.0 mg/L Cu+/2+ | 91358 |
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| VISOCOLOR® ECO Copper | 0 · 0.1 · 0.2 · 0.3 · 0.5 · 0.7 · 1.0 · 1.5 mg/L Cu2+ | 931037 |
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Reaction Basis
Copper(II) ions react with cuprizone (oxalic acid bis-(cyclohexylidene hydrazide)) in weakly alkaline solution to form a blue complex which can be evaluated colorimetrically and photometrically.
Cuprizone is very well suited for the photometric determination of small amounts of copper, as it reacts substantially selectively with copper(II) ions.
Sample preservation
After adjusting the pH value to 1–2 with nitric acid, the sample can be preserved for storage for up to 1 month (storage vessel: PE or glass bottle).
Tips & tricks
- Decomposition
- Only Cu2+ ions are detected. Copper(I) compounds and insoluble copper(II) compounds are not detected and must be decomposed before determination. For total copper determination, decomposition with NANOCOLOR® NanOx Metal (REF 918 978) or with the decomposition kit (REF 918 08) must be performed prior to analysis.
- Sea water suitability
- All VISOCOLOR® and NANOCOLOR® copper tests are suitable for sea water analysis.
- pH
- The pH value which is stated in the instruction leaflets for the sample solution must be complied with.
- Interferences
- Calcium interferes with the detection. For disturbance suppression, use the reagent for lime precipitation (up to 20 g/L Ca2+, REF 918 939).
- Chromium(III) concentrations higher than the concentration of copper interfere by causing minor results. For disturbance suppression use NANOCOLOR® NanOx Metal to oxidize Cr(III) to chromate.
- Further interfering ions are listed in the instruction leaflets.
- Turbidity
- Turbid solutions must be filtered prior to the determination of dissolved copper; turbidity leads to incorrect results: For coarsely dispersed turbidities, use qualitative filter paper (e.g. MN 615), for moderately dispersed turbidities, use glass-fiber paper (e.g. MN 85/70 BF) or or membrane filtration set GF/PET 0.45 μm, for finely dispersed turbidities, use membrane filtration kit 0.45 μm or GF/PET 0.45 μm.
