This standard specifies the limit requirements and determination methods for 4-aminoazobenzene (see Annex A) in dye products.
It applies to the limit and determination of 4-aminoazobenzene in commercial dyes, dye products, dye intermediates and textile dyeing auxiliaries.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods (ISO 3696:1987, MOD)
GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgment of limiting values
3 Requirements
The content of 4-aminoazobenzene (see Annex A) in dye products shall be less than or equal to 150mg/kg, in which the limit of 4-aminoazobenzene in liquid dye and pigment printing paste shall be converted according to its solid content.
4 Test methods
4.1 Gas chromatography-mass spectrometry (arbitration method)
4.1.1 Principle
The dye sample is subjected to reductive pyrolysis with sodium hydrosulfite in weakly alkaline medium, and the azo bond of 4-aminoazobenzene is kept non-breaking by controlling the pyrolysis temperature and the pyrolysis time; 4-aminoazobenzene in the pyrolysis solution is extracted with a solvent; after concentration, it is tested by gas chromatograph-mass spectrometer and quantified by characteristic ion external standard method.
4.1.2 Determination methods
4.1.2.1 General
Unless otherwise specified, only recognized analytical reagent and Grade 3 water (specified in GB/T 6682-2008) shall be used in analysis. Judgment of the inspection result shall be carried out according to the rounding-off value comparison method specified in GB/T 8170-2008, 4.3.3.
GB/T 24101-2018 The following standards are cited：
