Industrial Caprolactam Determination of Volatile Alkali Content—Titration Method after Distillation (1)

1 Scope

This part of GB/T 13255 specifies the determination of volatile alkali content in industrial caprolactam by titration after distillation

2 Normative references

The clauses in the following documents become clauses of this part through the reference of this part of GB/T13255

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

Preparation of reagents 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 (ISO3696:1987, MOD)

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

3 Principles of the method

In an alkaline medium, distill out the volatile base, absorb it with excess hydrochloric acid standard solution, use methyl red-methylene blue ethanol solution as an indicator, and back titrate with sodium hydroxide standard titration solution

4 Reagents

Unless otherwise specified, only reagents confirmed to be analytically pure and grade 3 water that meets the requirements of GB/T66822008 are used in the analysis

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5 Instruments

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The components of the distillation instrument are connected with rubber stoppers and rubber tubes.

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3 Zeolite
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Figure 1 Distillation instrument for determination of volatile alkali content in industrial caprolactam