Caldur® Nitrite LR – Colorimetric
Nitrite determination in the water using a color chart (0.05-1 mg/l NO₂-)
Private customers can also find our range in our partner store Ampha-Analyse.
Reagent for Caldur® Nitrite LR – Colorimetric:
See also:
CALDUR® Nitrite LR Test Set – Colorimetric
What is nitrite measured for?
Nitrite (NO₂-) is formed as an intermediate product during the bacterial oxidation of ammonium to nitrate (nitrification). It is an important Reagent for water quality, as its presence indicates incomplete biological treatment or fresh contamination. The limit value for drinking water is 0.5 mg/l NO₂- (Drinking Water Ordinance).
Nitrite is harmful to health as it can affect the oxygen supply in the blood (methaemoglobinaemia). A low nitrite concentration is particularly important for infants.
Nitrite is one of the most critical parameters in aquaristics, as even low concentrations are toxic to fish. In fish farming recirculation systems, seamless monitoring is essential.
How does the test set work?
The CALDUR® Nitrite LR Test Set – Colorimetric is based on the NED method (N-(1-naphthyl)-ethylenediamine). After adding a reagent to the water sample, a pink to violet coloration develops within 5 minutes, the intensity of which is proportional to the nitrite concentration.
The measured value is determined by direct color comparison with a supplied color chart.
Advantages of the CALDUR® test set
- Sensitive measuring range 0.05 – 1 mg/l NO₂-
Detects concentrations well below the drinking water limit value
- 200 provisions per set
Particularly economical for regular checks
- Quick analysis in just 5 minutes
Results directly on site
- Only 1 reagent required
Particularly easy handling
- Robust plastic housing with hinged lid
Safe transportation and protection of reagents
Areas of application
Carrying out the measurement:
- Fill water sample into test tubes up to the 10 ml mark
- Add 5 drops of reagent A and mix
- Wait for 5 minutes reaction time
- Perform color comparison with color chart
Tip for best results
The measurement should be carried out immediately after sampling, as nitrite is rapidly oxidized to nitrate in aerated samples. Do not shake the sample and protect it from direct sunlight.
Important notes
- Measure the sample immediately after taking it – nitrite oxidizes quickly to nitrate
- Adhere exactly to the response time of 5 minutes
- Avoid direct sunlight during the measurement
- High chlorine concentrations can interfere with the measurement
- Thoroughly rinse the test tube with the sample before each measurement
Measuring range
| Measuring level | Description |
|---|---|
| 0.05 mg/l | Very low concentration (pale pink) |
| 0.1 mg/l | Low concentration (light pink) |
| 0.2 mg/l | Slightly increased concentration (pink) |
| 0.3 mg/l | Medium concentration (deep pink) |
| 0.5 mg/l | Drinking water limit value (pink-violet) |
| 1.0 mg/l | High concentration (violet) |
If the color lies between two fields, you can form the mean value
(e.g. between 0.2 and 0.3 mg/l = approx. 0.25 mg/l).
Number of possible destinations
You can carry out 200 measurements with one CALDUR® Nitrite LR test set.
This refers to the quantity of reagents contained.
Measuring accuracy and reproducibility
Readability: ± 1 color level
Reproducibility: Very good if the application instructions are followed
Interference: Chlorine in high concentrations can influence the result. Highly colored samples make color readings more difficult. At high nitrate concentrations (>100 mg/l), slight interferences may occur.
What to do if measured values are out of range?
Measured value > 1.0 mg/l
| Verduction | Execution | Calculation of the measured value |
|---|---|---|
| 1:1 | 5 ml sample + 5 ml nitrite-free water | Measured value × 2 |
| 1:4 | 2 ml sample + 8 ml nitrite-free water | Measured value × 5 |
Measured value < 0.05 mg/l
measured value is below the detection limit. This is a good result for drinking water and aquariums.
Specifications at a glance
Reagents (1 reagent)
| Property | Value |
|---|---|
| Parameters | Nitrite (NO₂-) |
| Item number | 31-072350 |
| Method | Colorimetric (NED) |
| Measuring principle | Color comparison with 6-stage color chart |
| Measuring range | 0.05 to 1 mg/l NO₂- |
| Color scale | 6 measuring levels (0.05 / 0.1 / 0.2 / 0.3 / 0.5 / 1.0 mg/l) |
| Duration of analysis | 5 minutes |
| Number of provisions | 200 |
| Number of reagents | 1 |
| Packaging | Hinged lid box |
| Packaging size | 103 x 91 x 36 mm |
| weight | approx. 120 g |
| Scope of delivery |
|---|
| 1 reagent bottle (reagent A) with detailed labeling |
| 1 test tube with 10 ml scale |
| 1 color card with 6 measuring levels |
| Detailed operating instructions (DE/EN) |
| Safety data sheets for all reagents |
| Robust hinged lid box (103 x 91 x 36 mm) |
Reagent details
| Reagent | Volume | Shelf life | Notes |
|---|---|---|---|
| Reagent A (NED) | 30 ml | 24 months (24M) | NED reagent, shake 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 protected from direct sunlight.
Additional information
| Packaging | Hinged lid box, Refill pack |
|---|
Flyer
Operating instructions
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