CALDUR® Ammonium – Photometric
Ammonium determination in water photometric (0.1-3 mg/l NH₄⁺)
Private customers can also find our range in our partner store Ampha-Analyse.
Reagent for CALDUR® Ammonium – Photometric:
See also:
CALDUR® Ammonium Test Set – Photometric
What is ammonium measured for?
Ammonium (NH₄⁺) is an important indicator of water quality and is produced by microbial decomposition of organic material or enters the water through fertilizers, wastewater and agricultural inputs. An increased ammonium concentration can indicate contamination and must be monitored critically, especially in drinking water, aquariums and fish farms.
The limit value for drinking water in Germany is 0.5 mg/l NH₄⁺ (Drinking Water Ordinance). In bodies of water, ammonium serves as a nutrient for algae and plants, whereby increased concentrations can lead to eutrophication. Ammonium is toxic to fish – even small amounts can cause gill damage.
Ammonium control is essential in aquariums, as ammonium is first broken down by bacteria to nitrite and then to nitrate in the biological balance of the aquarium. Regular measurement protects fish from poisoning and provides information on the functionality of the biofilter.
How does the test set work?
The CALDUR® Ammonium Test Set – Photometric is based on the high-precision indophenol blue method. After adding three reagents to the water sample, a characteristic blue-green coloration develops within 8 minutes, the intensity of which is proportional to the ammonium concentration.
The evaluation is carried out photometrically using the WINLAB Data Line photometer, which enables a particularly precise measurement in the low concentration range. The method is highly specific for ammonium and exhibits only minimal cross-reactions with other nitrogen compounds.
Advantages of the CALDUR® test set
- Quick analysis in just 8 minutes
Ideal for regular checks in aquariums, fish ponds and sewage treatment plants – immediate results
- Precise measuring range from 0.1 to 3 mg/l NH₄⁺
Optimized for drinking water and aquarium applications with maximum accuracy
- 150 determinations per set – economical in continuous use
Cost-efficient for daily checks in aquaculture, waterworks and environmental analysis
- Photometric evaluation for precision measurements
Objective measurement results without subjective color assessment
- Highly specific method without interference
Precise measurement results even with complex water matrices
- Robust packaging in plastic bag or refill pack
Economical refill for continuous use
Areas of application
⚠️ Hazard information (from the label)
Ammonium reagent A – Danger
H290 May be corrosive to metals. H314 Causes severe skin burns and eye damage.
Ammonium reagent B
H411 Toxic to aquatic life with long lasting effects.
Ammonium reagent C – Danger
H315 Causes skin irritation. H318 Causes serious eye damage. H412 Harmful to aquatic life with long lasting effects.
Full information on all components: see the safety data sheet (SDS).
Carrying out the measurement:
- Fill water sample into test tube up to the 10 ml mark
- Add 3 drops of reagent A and mix
- Add 3 drops of reagent B and mix
- Add 1 dosing spoon of reagent C, shake well until completely dissolved
- Wait for 8 minutes reaction time (coloration develops)
- Perform photometric measurement with the WINLAB Data Line photometer
💡 Tip for best results
For best results, the water sample should be clear and free of suspended solids.
If the water is cloudy, pre-filtration with a filter paper (e.g. Whatman No. 1) is recommended.
The reaction time of 8 minutes should be strictly adhered to, as the color intensity is time-dependent.
For maximum precision, the photometer should be calibrated regularly.
⚠️ Important notes
- Bring reagents to room temperature before use (20-25°C)
- Precisely adhere to the reaction time of 8 minutes for precise measurement results
- Avoid direct sunlight during the measurement
- Rinse test tubes and photometer cuvette thoroughly with distilled water after use
- Chlorine in the water can interfere with the measurement – reduce with thiosulphate if necessary
Measuring range
| Measuring level | Description |
|---|---|
| 0.1 mg/l | Very low concentration |
| 0.25 mg/l | Low concentration |
| 0.5 mg/l | Drinking water limit value |
| 1.0 mg/l | Elevated concentration |
| 2.0 mg/l | High concentration |
| 3.0 mg/l | Very high concentration |
The photometric measurement enables a continuous reading between the measuring points
with high precision (resolution 0.01 mg/l possible).
Number of possible determinations
You can carry out 150 measurements with one CALDUR® Ammonium – Photometric test kit.
This refers to the quantity of reagents contained.
Measuring accuracy and reproducibility
Readability: ± 0.02 mg/l (photometric)
Reproducibility: Excellent if the application instructions are followed
Interferences: Turbidity and coloration of the sample can influence the result (filter the sample if necessary). High calcium concentrations (> 500 mg/l) can lead to slight deviations.
What to do if measured values are out of range?
Measured value > 3 mg/l
| Dilution | Procedure | Calculation of the measured value |
|---|---|---|
| 1:1 | 5 ml sample + 5 ml distilled water | Measured value × 2 |
| 1:4 | 2 ml sample + 8 ml distilled water | Measured value × 5 |
| 1:9 | 1 ml sample + 9 ml distilled water | Measured value × 10 |
Measured value < 0.1 mg/l
Measured value is below the detection limit. This is generally not critical and indicates
that the ammonium concentration is very low (water is harmless with regard to ammonium).
Specifications at a glance
Reagents (reagent A, B, C)
| Property | Value |
|---|---|
| Parameters | Ammonium (NH₄⁺) |
| Item number | 31-073212 |
| Method | Photometric (indophenol blue) |
| Measuring principle | Photometric measurement with WINLAB Data Line Photometer |
| Measuring range | 0.1 to 3 mg/l NH₄⁺ |
| Resolution | 0.01 mg/l (photometric) |
| Duration of analysis | 8 minutes |
| Number of determinations | 150 |
| Packaging | Plastic bag or refill pack |
| weight | approx. 150 g |
| Scope of delivery |
|---|
| 3 reagent bottles (reagent A, B, C) with detailed labeling |
| 1 test tube with 10 ml scale |
| Detailed operating instructions (DE/EN) |
| Safety data sheets for all reagents |
| Packaging: plastic bag or refill pack |
Reagent details
| Reagent | Volume | Shelf life | Notes |
|---|---|---|---|
| Reagent A | 10 ml | 36 months (36M) | Shake before use |
| Reagent B | 10 ml | 36 months (36M) | Shake before use |
| Reagent C | 5 g (powder) | 36 months (36M) | Store in a dry place, dissolve before use |
Shelf life: The shelf life starts from the date of manufacture (printed on the bottle).
After opening, the reagents should be used within 12 months.
Store the test kit in a dry, cool place (10-25°C) and away from direct sunlight.
Additional information
| Packaging | Plastic bag, Refill pack |
|---|---|
| Product category | Test kit |
