Determination of acrylonitrile peroxide content for industrial use. Spectrophotometric method (3)

7 Preparation of standard solution and drawing of calibration curve

7.

Prepare and calibrate according to one of the following methods

7.

7.

Use a pipette to transfer 2.

7.

7.

Note: The ammonium aluminate solution plays a catalytic role

7.

7.

7.

Where:

P _A — the exact concentration of hydrogen peroxide stock solution A, in milligrams per milliliter (mg/mL);

V ₁ —The volume of sodium thiosulfate standard solution consumed by the sample , in milliliters (mL);

V ₀ —The volume of sodium thiosulfate standard solution consumed by the blank solution , in milliliters (mL);

c — The concentration of the substance in the standard titration solution of sodium thiosulfate , in moles per liter (mol/L);

V— The volume of the removed hydrogen peroxide stock solution A, in milli (mL);

17.

7.

7.

Use a pipette to transfer 5 mL of hydrogen peroxide (5.

7.

7.
1.
2.
2.
1 Use a pipette to pipette 2mL solution B into two 100mL Erlenmeyer flask towels, and add 10mL sulfuric acid solution (5.
13)
.

7.
1.
2.
2.
2 Titrate with potassium permanganate standard titration solution (5.
12) until rose red appears, and it will not fade within 1 min
.

7.
1.
2.
2.
3 The exact concentration of solution B is calculated according to formula (2), and the arithmetic average of the two repeated determination results is taken as the analysis result
.

Where:

p _B — the accurate mass concentration of hydrogen peroxide stock solution B, in milligrams per milliliter (mg/mL);

V ₁ —The volume of potassium permanganate standard solution consumed by the sample , in milliliters (mL);

c— The concentration of the substance in the potassium permanganate standard titration solution, the unit is moles per liter (mol/L);

V—volume of hydrogen peroxide stock solution B to be removed;

17.
01— The mass of hydrogen peroxide expressed in milligrams is equivalent to 1.
00mL potassium permanganate standard titration solution [c(1/5KMnO ₄ )=1.
000mo/L] .

7.
1.
2.
2.
4 Use a pipette to transfer 5mL of solution B into a 50mL volumetric flask, dilute to the mark with water, mix thoroughly, called solution C, this solution contains about 1.
5mg/mL of hydrogen peroxide
.
The accurate mass concentration of solution C is calculated according to formula (3):

Where:

Pc— Accurate mass concentration of hydrogen peroxide stock solution C, in milligrams per milliliter (mg/mL);

PB—Accurate mass concentration of hydrogen peroxide stock solution B, in milligrams per milliliter (mg/mL)
.