ISO/DIS 25353:2025

This document specifies a qualitative procedure to qualifying leather animal species of (fibrous) protein from leather by MALDI-TOF mass spectrometer (MS). The composition of other fibres can be measured by methods described in the ISO 1833 series. Both results are then combined to determine the whole composition of fibres (see Annex C as an example of mixtures of (fibrous) protein from leather and polyester). The method is based on a preliminary identification, by light microscopy, of all fibres in a blend on the basis of their morphology, according to ISO/TR 11827.