GB/T 27741-2018 in English

Background and significance of the revision of GB/T 27741-2018

The GB/T 27741 series of standards are mainly used to determine the content of migratable fluorescent brighteners in paper and paperboard. The latest version (GB/T 27741-2018) has been significantly revised and improved in many aspects. This revision not only updates the scope of application and definition clauses, but also adds key indicators such as detection limit and recovery rate, further improving the scientificity and practicality of the standard.

Analysis of qualitative determination method

Qualitative determination mainly determines whether the sample contains migratable fluorescent brighteners by fluorescence phenomenon under ultraviolet light. The specific steps include:

1. Sample preparation: Cut the paper into small pieces and mix them evenly.
2. Extraction and filtration: Use an extraction solution adjusted to a specific pH value for extraction and filter through a glass funnel.
3. Gauze adsorption: immerse the filtrate under ultraviolet light to observe the fluorescence phenomenon.

Comparison of quantitative determination methods

Main changes in the revision of the standard

Comparison between the old and new standards:

• Scope of application: The new standard expands the detection requirements for migratable fluorescent whitening agents in pulp.
• Definition of terms: The migration characteristics of "migratable fluorescent whitening agents" under specific conditions are clearly defined.
• New equipment: Key instruments such as a constant temperature oscillating water bath and a high performance liquid chromatograph are introduced.
• Data requirements: The detection limit and recovery rate indicators are added to improve the reliability of the test results.

Implementation suggestions