Test methods for industrial acetates (5)

3.

3.

3.

The water in the sample reacts quantitatively with the iodine and sulfur dioxide in the electrolyte, and the reaction formula is:

I ₂ +SO ₂ +H ₂ O→2HI+SO ₃

2I ^-- 2e→I ₂

The number of molecules participating in the reaction is equal to the number of water molecules, and the iodine produced by electrolysis is proportional to the amount of electricity consumed.

3.

Electrolyte: Karl Fischer reagent or the electrolyte used with the Karl Fischer coulometric moisture analyzer (commercially available reagent)

3.

3.

3.

3.

Add electrolyte, adjust the instrument according to the instrument manual, when the instrument enters the working state, calibrate according to the requirements of the instrument manual

Take 50uL or an appropriate amount of sample and inject it into the moisture analyzer.

3.

If what is read is the quality of water, the mass fraction of water w ₁ , the value is expressed in %, calculated according to formula (5):

Where:

m ₁ ——The value of the quality of water read on the display screen of the moisture analyzer, in micrograms (ug);

p _t ——The value of the density of the sample at the measured temperature, in grams per milliliter (g/mL);

V——The value of the sample volume, the unit is microliter (uL)

3.

Measure according to the method specified in 3.
10.
2
.

3.
11.
3 Karl Fischer direct coulometric titration

Measure according to the method specified in GB/T6283-1986
.