Industrial caprolactam. Determination of the absorption value of potassium permanganate. Spectrophotometric method (1)

1 Scope

This part of GB/T13255 specifies the spectrophotometric method to determine the potassium permanganate absorption value (PAN) of caprolactam for industrial use

2 Normative references

The clauses in the following documents become clauses of this part after being quoted in this part of GB/T 13255

Preparation of GB/T 601-2002 Chemical Reagent Standard Titration Solution

Preparation of preparations and products used in GB/T 603-2002 chemical reagent test method (ISO6353-1:1982, NEQ)

GB/T 6682-2008 Analytical laboratory water specifications and test methods (1SO3696: 1987, MOD)

GB/T 8170 Numerical Rounding Rules and the Expression and Judgment of Limit Values

3 Terms and definitions

The following terms and definitions apply to this standard

3.

Potassium permanganate absorbance (PAN) permanganate absorption number (PAN ) 3% (mass fraction) hexyl lactam neutral buffer solution was added C (.

4 Principles of the method

Add a certain volume of potassium permanganate standard titration solution to the neutral sample solution, react at (25.

5 Reagents

Unless otherwise specified in this section, the reagents and water used refer to analytical reagents and tertiary water that meets the requirements of GB/T 6682-2008

The standard titration solutions, preparations and products used in the analysis shall be prepared in accordance with the provisions of GB/T 601-2002 and GB/T 603-2002 when other requirements are not specified

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Dissolve 1.

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8 PAN water:

Add 2.
5mL pH 7.
0 buffer solution to a 1L volumetric flask and dilute to the mark
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And carry out the blank test according to 7.
3, the absorbance of the blank test is not more than 0.
03, the solution should be prepared every day
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If the analysis water fails to meet the requirements, add 1g potassium permanganate per liter of water , leave it for 24h, and then use a 600mm long thorn-shaped fractionation column to distill, discard the first 50ml distillate, collect 750ml distillate, and identify After this distillate meets the above requirements, it can be used as analysis water
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5.
9 Standard titration solution of potassium permanganate : (1/5KMnO ₄ )=0.
01mol/L
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Store in a brown bottle, ready to use when used
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