For determination of Hypochlorite (Bleach) by Digital Titrator titration.
Article 2687000 measures hypochlorite 5-15% as Cl₂ (50-150 g/L Cl₂) for concentrated liquid bleach (sodium hypochlorite, soda bleach) used as disinfectant in drinking water and wastewater treatment. Hypochlorite Bleach Reagent Set uses Iodometric Titration method (10100). Each pack can be used for 100 tests.
Hypochlorite Bleach Reagent Set includes:
- Acid Reagent Powder Pillows (p/n 104299)
- Potassium Iodide Powder Pillows (p/n 2059996)
- Sodium Thiosulfate Titration Cartridge, 2.26 N (p/n 2686901)
- Starch Indicator Solution (p/n 34932)
Before starting analysis:
- It is required to collect the sample in clean glass containers.
- It is necessary to prevent the sample exposure to heat or light.
- For best results analyze the samples as soon as possible.
Procedure for hypochlorite determination
Install the delivery tube into the 2.26 N Sodium Thiosulfate Titrant Solution cartridge and attach the cartridge to the Digital Titrator. After that rotate the delivery knob to eject air and a few titrant drops, reset the counter to zero and clean the tip of the Digital Titrator. Mix 75mL of deionized water or tap water and Potassium Iodide Powder Pillow in the 125mL Erlenmeyer flask. Pour the content of Acid Reagent Powder Pillow and swirl the Erlenmeyer flask. Pipet 0.2 mL of bleach sample and swirl to mix. Add titrant using Digital Titrator until the color changes to pale yellow. Then pipet one dropperful of Starch Indicator Solution and swirl the content of the Erlenmeyer flask. Continue adding titrant until the color changes from dark blue to colorless and calculate the concentration:
- digits used × 0.5 = g/L chlorine
- g/L chlorine × 0.10 = % chlorine by volume
Summary of method
In acidic conditions, hypochlorite enters into reaction with iodide forming equivalent quantity of triiodide. The released triiodide is titrated with sodium thiosulfate to colorless end point. The quantity of sodium thiosulfate required is directly related to the hypochlorite concentration in the sample.
| Brand | Hach |
| Parameter | Chlorine, Hypochlorite |
| Measuring range | 5-15% as Cl₂ (50-150 g/L Cl₂) |
| Method | Iodometric Titration method |
| Standard method | 10100 |
| Number of tests | 100 tests |
