3-Chloroperoxybenzoic Acid mCPBA CAS 937-14-4 Purity ≥85.0% (by Na2S2O3 Titration) (Wet with Water)

3-Chloroperoxybenzoic Acid (mCPBA) (CAS: 937-14-4) Method of Analysis:
Instrument: Electronic balance
Reagents and solutions:
Chloroform and acetic acid analytically pure
10% Potassium iodide solution: Take 10g Potassium iodide, add water to dissolve and dilute to 100ml, shake well, and then get.
Sodium thiosulfate titration (0.05mol/L): Take 26g of Sodium thiosulfate and 0.2g of anhydrous Sodium carbonate, add a suitable amount of newly boiled cold purified water, dissolve into 1000ml, shake well, and prepare 0.1mol/L Sodium thiosulfate titration. Leave for 1 month and strain.
The 0.1mol/L Sodium thiosulfate titration prepared before use was diluted with newly boiled cold water to produce 0.05mol/L sodium thiosulfate titrant.
0.5% (g/ml) starch indicator liquid: Take 0.5g of soluble starch, add 5ml of purified water, stir well, slowly pour into 100ml boiling water, add and stir, continue to boil for 2 minutes, cool, pour out the superwhite liquid, and get.
Determination: Take about 50mg of chlorperoxybenzoic acid, weigh it accurately, add 5ml chloroform to dissolve, add 10ml of 10% potassium iodide (sodium) solution and 5ml of acetic acid, and dilute it with 30ml of distilled water. After reaction for 10min, titrate with sodium thiosulfate titration solution (0.05mol/L), drop the brown-red solution (dark red solution) to light brown-yellow. At this time, add 0.5% (g/ml) starch indicator solution 1ml, continue titration until the water layer becomes colorless, that is, the end point. Each 1ml of sodium thiosulfate titrator (0.05mol/L) is equivalent to 4.31mg of C7H5ClO3. The measured content shall not be less than 83.0%. (≥83.0%)
Percentage of 3-Chloroperoxybenzoic Acid (C) is calculated as follows:
C=Vxcx0.00431/mx100%
Where: V - the volume of Sodium thiosulfate titration consumed by the sample, ml;
c - Sodium thiosulfate titration concentration, mol/L;
m - Sample mass, g;
Allowable deviation: The test subject should be measured twice in parallel, and the relative average deviation of the two test results should be no more than 0.3%, and the arithmetic average of the two test results should be taken as the reported result.
Relative average deviation: