The Macherey Nagel VISOCOLOR® HE Chlorine Test Kit is a high-sensitivity solution for precise measurement of free and total chlorine in water. Designed for applications in swimming pools, water reservoirs, and water mains, this test kit ensures effective disinfection while maintaining safe chlorine levels.
Why Monitor Chlorine Levels?
Chlorine is widely used for water disinfection, effectively destroying harmful microorganisms, removing impurities, and preventing algae growth. However, maintaining an optimal chlorine concentration is crucial. Excessive chlorine can impair the water’s smell and taste and may pose health hazards.
Key Chlorine Parameters
Free Chlorine: Dissolved chlorine in the form of elemental chlorine, hypochlorous acid, and hypochlorite ions.
Bound Chlorine: Inorganic and organic chloroamines.
Total Chlorine: The sum of free and bound chlorine.
The VISOCOLOR® HE Test Kit enables accurate measurement of these parameters, ensuring water quality and safety.
Methodology
The test employs a colorimetric determination where free chlorine reacts with N,N-diethyl-1,4-phenylene diamine (DPD) in a phosphate-buffered system (pH 6.2 to 6.5). This reaction forms a red-violet dye. In the presence of iodide ions, total chlorine (free and combined) can also be determined.
Measurement Range
0.02–0.60 mg/L Cl₂
Test Kit Contents
24 g Cl₂-1
100 mL Cl₂-2 (refillable)
30 mL Cl₂-3 (refillable)
1 black measuring spoon (85 mm)
1 plastic beaker
2 round glass tubes with screw caps
1 comparator block
1 color comparison disc
Step-by-Step Procedure
- Prepare the Comparator: Insert the color comparison disc.
- Prepare the Sample:
- Rinse both round glass tubes with the water sample.
- Fill both tubes to the mark with the sample.
- Free Chlorine Measurement:
- Add 1 level black measuring spoon of Cl₂-1 to the right tube.
- Add 12 drops of Cl₂-2, close, and mix.
- Immediately match the color using transmitted light and read the result from the comparator.
- Total Chlorine Measurement:
- Add 3 drops of Cl₂-3 to the right tube, close, and mix.
- Wait 2 minutes.
- Match the color again and record the result.
- Calculate Bound Chlorine: Subtract the free chlorine value from the total chlorine value.
Notes for Accurate Results
Ensure the water sample temperature is between 15°C and 30°C.
Rinse glass tubes thoroughly to prevent contamination.
Residues of Cl₂-3 may lead to higher readings of free chlorine.
Interferences
Higher manganese compounds can simulate free chlorine.
Chlorine levels exceeding 4 mg/L may destroy the red dye, resulting in low readings.
The method is suitable for seawater analysis.
Additional Information
Conversion Factors:
0.10 mg/L Cl₂ = 0.18 mg/L ClO₂ = 0.15 mg/L OCl⁻ = 0.21 mg/L NaOCl = 0.23 mg/L Br₂ = 0.36 mg/L I₂.
Bromine Analysis: If chlorine is present, it can be neutralized with glycine (approx. 20 mg in 25 mL). The bromine concentration can then be determined using the sample solution. Result in mg/L Cl₂ × 2.25 = mg/L Br₂.
Storage and Disposal
Storage: Keep the test kit in a cool and dry place.
Disposal: Refer to the safety data sheet for proper disposal instructions. Detailed SDS are available at www.mn-net.com/SDS.
The Macherey Nagel VISOCOLOR® HE Chlorine Test Kit is an essential tool for water quality control, providing high sensitivity and reliable results for free and total chlorine measurement. Its comprehensive design and straightforward methodology make it a trusted choice for both professionals and laboratories.