GB/T 6324.7-2014Test method of organic chemical products—Part 7: Determination of molten color (English PDF)

3.1 General provisions

Unless otherwise indicated in the analysis using only recognized as analytical reagents and in line with GB/T 6682 tertiary water.

Used in the analysis and formulation of products, in the absence of other specified requirements, prepared according to GB/T 603's.

3.2 visual colorimetry

3.2.1 Method summary

The test sample was heated at a preset temperature to melt completely, the color of the sample immediately after thawing and standard platinum - cobalt colorimetric solution color mesh

Comparison of measured and platinum - cobalt color number shows the results.

3.2.2 Instruments

3.2.2.1 Nessler colorimetric tube

50mL; heat-resistant material shall meet the requirements of the melting temperature of the sample; glass color and scale line should be the same height.

3.2.2.2 Electric heating block

aluminum, performance requirements, see Appendix A. Other heating requirements can be achieved and the precision of the heating device may also be used.

3.2.2.3 colorimetric tube frame

Usually the color than the bottom rack white floor lining the bottom mirror can also be safe there, observe the color to enhance the effect.

3.2.2.4 Spectrophotometer

shall comply with GB/T 9721's.

3.2.3 Preparations

3.2.3.1 platinum - cobalt color standard preparation liquor ratio (500Hazen unit)

Commercially or in accordance with GB/T 3143 formulated. The mother liquor can be used standard colorimetric spectrophotometer cuvette than 1cm of the following wavelengths […]