Reagents for the determination of the concentration of the ozone aging box

The reagents should be analytical grade ozone aging chambers. Distilled water should be used throughout the test.

1. Starch indicator solution: 1g of soluble starch is added to 40mL of cold water, stirring continuously, and heating to boiling until the starch is completely dissolved. Dilute with cold water to about 200Ml, then add 2g of crystalline zinc chloride to clarify the solution, and pour out the supernatant for use. The solution should be replaced every two or three days for storage and regular use. Alternatively, 1 g of soluble starch can be dissolved in 100 mL of boiling water to prepare a fresh solution. No matter which starch solution is used as an indicator, a few drops of 10% acetic acid should be added to the solution for titration.

2. Standard iodine solution: add 2g of potassium iodide (KI) and 10Ml of water to the weighing tube and weigh it, then add iodine to the solution in the weighing tube placed on the balance plate until the total The weight is about 0.1g. Accurately weigh the iodine-containing solution and determine the amount of iodine added. Pour the solution into the beaker, wash the weighing tube with distilled water on the beaker, pour the solution in the beaker into a 1000mLJ measuring flask, then pour the distilled water from the rinse beaker into the measuring flask and dilute to 1000mL. (Note: The solution is quite stable if stored in a dark, cold place and in a tightly packed brown bottle.)

3. Sodium thiosulfate solution: Place about 0.24g of Na? S? O ?? 5H? O in a 1000mL volumetric flask and dilute to 1000mL to make sodium thiosulfate (Na? S? O?) Solution. Since the sodium thiosulfate solution will gradually decrease, this solution should be calibrated for the iodine solution on the day of the odor test.

The concentration E of the Na? S? O? Solution is calculated according to the iodine equivalent, and expressed as the number of iodine per liter of solution. The formula is: E = FC / S

In the formula: F-volume of iodine solution, mL;

C― Iodine concentration, mg / mL;

S―Na? S? O? Solution volume for titration, mL.

4. Potassium iodide solution: Dissolve about 20g of pure KI in 2000 mL of water.

V. Acetic acid: prepare 10% solution (by volume ratio).

The above is the content of the reagent for measuring the concentration of the ozone aging box.