Caldur® Chrome – Colorimetric
Chromium (VI) determination in water by color chart (0.05-2.0 mg/l Cr VI)
Private customers can also find our range in our partner store Ampha-Analyse.
Reagent for Caldur® Chrome – Colorimetric:
See also:
CALDUR® Chromium test set – Colorimetric
What is chromium measured for?
Chromium is a heavy metal that occurs in various oxidation states. Hexavalent chromium (chromium VI or chromate), which is considered toxic and carcinogenic, is particularly relevant for water analysis. Chromium mainly enters the water through industrial processes such as electroplating, tanning, metal finishing and steel production. Natural sources such as chromium-containing rocks can also contribute to contamination.
The limit value for drinking water is 0.05 mg/l chromium (Drinking Water Ordinance). As chromium VI is considerably more toxic than chromium III, particular importance is attached to the determination of this form in water monitoring. Regular monitoring is essential for the protection of health and compliance with environmental regulations.
How does the test set work?
The CALDUR® Chromium Test Set – Colorimetric works according to the proven diphenylcarbazide method. Hexavalent chromium (Cr VI) reacts with 1,5-diphenylcarbazide in an acidic solution to form a violet-red color complex. The intensity of the coloration is directly proportional to the chromium concentration in the sample.
The measured value is determined by direct color comparison with a supplied 6-stage color chart. This colorimetric method enables fast and reliable on-site determination without the need for expensive laboratory equipment. Optionally, the sample can also be evaluated photometrically with the WINLAB Data Line photometer.
Advantages of the CALDUR® test set
- Quick analysis in just 5 minutes
Ideal for on-site use – saves time and enables immediate decisions
- High precision in the relevant concentration range (from 0.05 mg/l)
Perfect for compliance with the Drinking Water Ordinance and for sensitive applications
- 150 provisions per set – economical in continuous use
Cost-efficient for regular inspections in industry and waterworks
- Can be used colorimetrically and optionally photometrically
Flexible for simple on-site tests or precise laboratory analyses with photometer
- Specific for chromium VI (chromate)
Determination of the toxic relevant chromium form – important for health protection
- Robust, waterproof plastic housing with hinged lid
Safe transportation and protection of reagents – durable and reliable
Areas of application
Carrying out the measurement:
- Fill water sample into test tube up to the 10 ml mark
- Add 5 drops of reagent A (acid) and mix
- Add 5 drops of reagent B (diphenylcarbazide) and mix
- Wait for 5 minutes reaction time
- Evaluation by color comparison with color chart or photometric measurement
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 5 minutes should be observed for optimum color development.
Important notes
- Bring reagents to room temperature before use
- Adhere exactly to the reaction time of 5 minutes
- Avoid direct sunlight during the measurement
- Rinse test tubes thoroughly with distilled water after use
- This test kit only determines chromium VI (chromate)
Measuring range
| Measuring level | Description |
|---|---|
| 0.05 mg/l | Very low concentration (light pink) |
| 0.1 mg/l | Low concentration (pink) |
| 0.25 mg/l | Elevated concentration (pink-violet) |
| 0.5 mg/l | Average concentration (violet) |
| 1.0 mg/l | High concentration (dark violet) |
| 2.0 mg/l | Very high concentration (deep violet) |
If the color lies between two fields, you can form the mean value
(e.g. between 0.1 and 0.25 mg/l = approx. 0.15-0.2 mg/l).
Number of possible provisions
You can carry out 150 measurements with one CALDUR® Chromium 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: High concentrations of iron or mercury can influence the result. Strongly colored or cloudy samples should be pre-filtered.
What to do if measured values are out of range?
Measured value > 2.0 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 < 0.05 mg/l
The measured value is below the detection limit. This is generally not critical and indicates that the chromium concentration is very low (water is harmless with regard to chromium).
Specifications at a glance
Reagents (reagent A, reagent B)
| Property | Value |
|---|---|
| Parameters | Chromium VI (Cr VI) |
| Item number | 31-072280 |
| Method | Colorimetric (diphenylcarbazide) |
| Measuring principle | Color comparison with 6-stage color chart |
| Measuring range | 0.05 to 2.0 mg/l Cr VI |
| Color scale | 6 measuring levels (0.05 / 0.1 / 0.25 / 0.5 / 1.0 / 2.0 mg/l) |
| Duration of analysis | 5 minutes |
| Number of provisions | 150 |
| Packaging | Hinged lid box |
| Packaging size | 103 x 91 x 36 mm |
| weight | approx. 150 g |
| Scope of delivery |
|---|
| 2 reagent bottles (reagent A, reagent B) 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 (acid) | 30 ml | 24 months (24M) | Shake before use |
| Reagent B (diphenylcarbazide) | 25 ml | 24 months (24M) | 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 away from direct sunlight.
Additional information
| Packaging | Hinged lid box, Refill pack |
|---|
Flyer
Operating instructions
Instructions for use
Instructions for use
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