Caldur® Sulfide – Colorimetric
Determination of sulphide in water using a color chart (0.05-1.0 mg/l S²-)
Private customers can also find our range in our partner store Ampha-Analyse.
Reagent for Caldur® Sulfide – Colorimetric:
See also:
CALDUR® Sulfide Test Set – Colorimetric
What is sulfide measured for?
Sulphide (S²-) is produced by the anaerobic decomposition of organic substances containing sulphur and can cause an unpleasant smell of rotten eggs as hydrogen sulphide (H₂S). Even low concentrations are corrosive and can damage pipelines and structures.
Sulphide is harmful to health in higher concentrations and can cause respiratory and eye irritation in people who work with contaminated water. Sulphide is undesirable in drinking water treatment and must be reliably detected.
In industrial water treatment, in sewage treatment plants and in groundwater samples, sulphide control is essential to prevent corrosion and ensure water quality.
How does the test set work?
The CALDUR® Sulfide Test Set – Colorimetric is based on the DPD method. After adding two reagents to the water sample, a characteristic coloration develops within 7 minutes, the intensity of which is proportional to the sulfide concentration.
Advantages of the CALDUR® test set
- Sensitive measuring range 0.05 – 1.0 mg/l S²-
Detection of even low sulphide concentrations
- 100 provisions per set
Economical for regular checks
- Easy handling
Fast on-site determination without measuring devices
- Proven DPD method
Reliable and reproducible results
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
- Add 3 drops of reagent B and mix
- Wait for 7 minutes reaction time
- Perform color comparison with color chart
Tip for best results
The sample should be measured immediately after collection, as sulphide forms volatile hydrogen sulphide (H₂S). Do not shake or aerate the sample in order to avoid sulphide losses.
If H₂S can be detected by smell (from approx. 0.05 mg/l), a measurement is strongly recommended.
Important notes
- Do not aerate or shake the sample – sulphide volatilizes as H₂S
- Adhere exactly to the reaction time of 7 minutes
- Avoid direct sunlight during the measurement
- Reading may be more difficult with heavily colored samples
- Thoroughly rinse the test tube with the sample before each measurement
- H₂S is toxic – work in a fume cupboard at high concentrations
Measuring range
| Measuring level | Description |
|---|---|
| 0.05 mg/l | Very low concentration (pale yellow) |
| 0.1 mg/l | Low concentration (light yellow) |
| 0.2 mg/l | Slightly increased concentration (yellow) |
| 0.3 mg/l | Medium concentration (strong yellow) |
| 0.5 mg/l | Increased concentration (yellow-brown) |
| 1.0 mg/l | High concentration (brown) |
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 100 measurements with one CALDUR® Test Set Sulfide.
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: Strongly reducing substances can influence the result. In the case of strongly colored samples (e.g. due to humic substances), the color reading may be more difficult. In these cases a photometric determination is recommended.
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 sulfide-free water | Measured value × 2 |
| 1:4 | 2 ml sample + 8 ml sulfide-free water | Measured value × 5 |
Measured value < 0.05 mg/l
The measured value is below the detection limit. For more sensitive measurements, the photometric CALDUR® Sulfide test set (0.05-1.0 mg/l with higher resolution) can be used.
Specifications at a glance
| Property | Value |
|---|---|
| Parameters | Sulphide (S²- / H₂S) |
| Item number | 31-072540 |
| Method | Colorimetric (DPD) |
| Measuring principle | Color comparison with 6-stage color chart |
| Measuring range | 0.05 to 1.0 mg/l S²- |
| Color scale | 6 measuring levels (0.05 / 0.1 / 0.2 / 0.3 / 0.5 / 1.0 mg/l) |
| Duration of analysis | 7 minutes |
| Number of provisions | 100 |
| Number of reagents | 2 |
| Packaging | Hinged lid box |
| Packaging size | 103 x 91 x 36 mm |
| weight | approx. 140 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 (DPD 1) | 30 ml | 24 months (24M) | DPD reagent, shake before use |
| Reagent B (buffer) | 10 ml | 24 months (24M) | Buffer solution, 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 |
|---|
