Industrial manganese acetate (2)

4 Test method

When the reagents and water used in this standard are not marked with other special requirements, the analytical reagents and the tertiary water specified in GB/T6682 shall be used

Standard solutions used in this standard, standard solutions for impurity determination, preparations and products, unless other special requirements are specified, are prepared in accordance with GB/T 601, GB/T602, and GB/T603

4.

4.

The sample is titrated with EDTA standard titration solution in the presence of ammonia-ammonium chloride buffer solution, and the titration end point is judged by the color change of chrome black T indicator

4.

4.

4.

4.

4.

4.

Weigh 0.

Do a blank test at the same time

4.

The content (X ₁ ) of manganese acetate expressed in mass percentage [ calculated as Mn(CH ₃ COO) ₂ ·4H ₂ O] is calculated according to formula (1):

In the formula: V ₁ -the volume of EDTA standard titration solution consumed by the sample, mL;

V ₂ —Blank consumption volume of EDTA standard titration solution, mL;

c—The actual concentration of EDTA standard titration solution, mol/L;

0.

m—the mass of the sample, g
.

4.
1.
5 Tolerance

Take the arithmetic average of the two measurement results as the measurement result
.
The difference between the two parallel determination results shall not be more than 0.
2%
.

4.
2 Determination of water-insoluble matter 4.
2.
1 Instruments and equipment

Glass crucible: The aperture of the filter plate is 5um～15um
.

4.
2.
2 Analysis steps

Weigh 20g of the sample (accurate to 0.
01g), place it in a 500mL beaker, add 80mL of water to dissolve, filter with a glass crucible of constant mass in advance, and wash the filter residue 5 times with 100ml of hot water
.
Dry at 105℃～110℃ until the quality is constant
.

4.
2.
3 Expression of analysis results

The water-insoluble content (X ₂ ) expressed in mass percentage is calculated according to formula (2):

Where: m—mass of crucible plus residue, g;

m ₁ —The mass of the crucible, g;

m—the mass of the sample, g
.

4.
2.
4 Allowable difference

Take the arithmetic average of the two measurement results as the measurement result
.
The difference between the two parallel determination results shall not be greater than 0.
002%
.

4.
3 Determination of sulfate

4.
3.
1 Reagents and solutions

4.
3.
1.
1 95% ethanol
.

4.
3.
1.
2 Hydrochloric acid solution: 2+1
.

4.
3.
13 Barium chloride solution: 100g/L
.

4.
3.
1.
4 Sulfate standard solution: 1ml, the solution contains 0.
1mg SO42-
.

4.
3.
2 Analysis steps

Weigh 2g sample (accurate to 0.
01g), place it in a 100mL beaker, add 0.
6mL hydrochloric acid solution, dissolve it with water and dilute to 50mL, filter with dry filter paper, and discard about 10mL initial filtrate
.
Take 25mL of the filtrate into a 50mL colorimetric tube, add 3mL of "95% ethanol" and 2mL of barium chloride solution, shake well, and place for 1h
.
Compared with the standard turbidity solution, its turbidity shall not exceed the turbidity of the standard turbidity solution
.

Standard turbidity solution: Take 2mL sulfate standard solution, place it in a 50mL colorimetric tube, add 0.
3mL hydrochloric acid solution, dilute to 25mL with water, then add 3mL "95% ethanol " and 2mL barium chloride solution, mix well, and place 1h spare
.

4.
4 Determination of chloride

4.
4.
1 Reagents and solutions

4.
4.
1.
1 Nitric acid solution: 1+2
.

4.
4.
1.
2 Silver nitrate solution: 20g/L
.

4.
4.
1.
3 chloride standard solution: 1ml CI solution containing 0.
1 mg ^-
.

4.
4.
2 Analysis steps

Weigh 1g sample (accurate to 0.
01g), place it in a 50mL colorimetric tube, add 5mL nitric acid solution to dissolve, add water to 25mL, add 1mL silver nitrate solution, shake well, and place for 15min
.
Compared with the standard turbidity solution, its turbidity shall not exceed the turbidity of the standard turbidity solution
.

Standard turbidity solution: Take the chloride standard solution (0.
2mL for excellent products, 1mL for first-class and qualified products), and process the same as the sample at the same time
.