2272200 Dissolved Oxygen Reagent Set, 1-10 mg/L O₂

Article 2272200 measures dissolved oxygen 1-10 mg/L O₂ in water, wastewater and seawater. The product uses Winkler method (8215). Dissolved Oxygen Reagent Set may be used to perform analysis of 50 samples.

Dissolved Oxygen Reagent Set includes:

• Alkaline Iodide-Azide Powder Pillows (p/n 107266)
• Manganous Sulfate Powder Pillows (p/n 107166)
• Sodium Thiosulfate Titration Cartridge (p/n 2267501)
• Starch Indicator Solution (p/n 34932)
• Sulfamic Acid Powder Pillows (p/n 2076266)

Before starting analysis:

• It is requited to collect the sample with clean BOD bottles.
• It is recommended to use the TitraStir Titration Stand to hold the Digital Titrator and stir the sample.

Procedure for O₂ determination

Pour the content of Manganous Sulfate Powder Pillow and Alkaline Iodide-Azide Reagent Powder Pillow to the sample. Install the stopper in the bottle and invert the bottle content a few times. Remove the stopper and add Sulfamic Acid Powder Pillow to the sample. Then put the stopper in the bottle and invert the bottle several times. Insert delivery tube into the digital titration cartridge and attach the cartridge to the Digital Titrator. After that transfer the sample into 250-mL Erlenmeyer flask. Add titrant to the solution until the color changes yellow to a pale yellow. After pouring 2 mL of Starch Indicator Solution, a dark blue coloration appears. Add titrant until the color changes from dark blue to colorless end point. Record the number of digits on the counter and calculate the concentration.

Summary of method

Sample is treated with manganous sulfate and alkaline iodide-azide reagent to form orange/brown precipitate. After acidification of the sample, this floc enters into reaction with iodide producing free iodine as triiodide in proportion to the oxygen concentration. The iodine is titrated with sodium thiosulfate to a colorless end point.