Cleavage Standard
A standardized analytical procedure governs the detection of restricted aromatic amines derived from cleavage of azo colorants in natural and synthetic textile products. Technical implementation of ISO 14362-1 Azo Dyes testing determines whether specific azo colorants capable of releasing carcinogenic amines were used during fabric dyeing or printing. Fiber samples undergo reductive cleavage using sodium dithionite in buffered neutral aqueous media.
Extracted amine species undergo qualitative and quantitative analysis using gas chromatography or liquid chromatography equipment.
Reduction Phase
Chemical reduction breaks azo nitrogen-nitrogen double bonds inside closed reaction vessels at seventy degrees Celsius. Sodium dithionite acts as the reducing agent, liberating free aromatic amines into solution within thirty minutes. Controlling temperature and reaction time prevents unwanted degradation of non-target chemical structures.
Liquid-liquid extraction using t-butyl methyl ether isolates liberated amines from the aqueous reaction mixture.
Chromatographic Extraction
Concentrated amine extracts undergo chromatographic separation to distinguish specific regulated aromatic amines from non-restricted structural isomers. Diatomaceous earth column purification removes residual dye fragments and matrix interferences before analytical injection. Gas chromatography paired with mass spectrometry confirms chemical structures by matching retention times and mass spectra against reference standards.
Regulatory Threshold
Detection of any listed aromatic amine above thirty milligrams per kilogram constitutes a violation of global chemical compliance standards.
