ISO 1833-20:2009 Preview
Textiles -- Quantitative chemical analysis -- Part 20: Mixtures of elastane and certain other fibres (method using dimethylacetamide)
ISO 1833-20:2009 specifies a method using dimethylacetamide to determine the
percentage of elastane, after removal of non-fibrous matter, in textiles made of binary mixtures of certain elastane fibres with cotton, viscose, cupro, modal, polyamide, polyester or wool fibres.
This method is not applicable when acrylic fibres are present.