GB/T 27594-2025Disperse dyestuffs - Determination of relative strength - Spectrophotometer method (English PDF)

1 Scope

This document describes a spectrophotometric method for determining the relative intensity of disperse dyes.

This document applies to the determination of the relative intensity of disperse dyes that conform to the Lambert-Beer law.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies.

This document.

GB/T 2374-2017 General conditions for dyeing determination

GB/T 6687 Dye Terminology

GB/T 8170-2008 Rules for rounding off numerical values and the representation and determination of limiting values

3 Terms and Definitions

The terms and definitions defined in GB/T 6687 apply to this document.

4 Principles

After dissolving the disperse dye sample and standard in a solvent, the absorbance at the maximum absorption wavelength was measured using a spectrophotometer.

The relative intensity of the disperse dye sample was calculated using Lambert-Beer's law.

5 Instruments and Equipment

The instruments and equipment used should meet the following requirements.

a) Spectrophotometer. Operating wavelengths range from 380nm to 700nm; Cuvette optical path is 10mm.

b) Electric drying oven. controllable temperature ±2°C;

c) Analytical balance. minimum scale division not greater than 0.0001g;

d) Volumetric flasks. 500mL, 100mL;

e) Single-mark pipettes. 1mL, 2mL.

6 Reagents and Materials

Reagents and materials shall comply with the relevant provisions of Chapter 3 of GB/T 2374-2007.

a) Acidic solution of dimethylformamide (DMF). Add 1 mL of concentrated sulfuric acid to each liter of DMF and mix thoroughly. […]