Overview
EN ISO 20418-3:2020 (ISO 20418-3:2020) specifies a qualitative and quantitative proteomic procedure for determining the composition of animal hair fibre blends using LC‑MS without protein reduction. The method targets common luxury and commodity animal fibres-wool, cashmere, yak, alpaca, camel, and angora-and is designed for robust peptide detection after trypsin digestion of powdered fibres. The standard is intended for textile testing laboratories, quality control and authentication of fibre blends (for example, cashmere authentication), and regulatory or forensic investigations involving fibre composition.
Key topics and technical requirements
- Scope: Determination of animal hair fibre blend composition by LC‑MS without a reducing step. Non‑animal fibres should be analysed by ISO 1833 and combined with LC‑MS results for total composition.
- Preliminary identification: Light microscopy morphological identification (per ISO/TR 11827) to identify fibre types prior to LC‑MS analysis. The method is not applicable when fibres from the same animal species are blended (e.g., cashmere and mohair).
- Sample preparation: Degreasing, mechanical powderization of fibres and trypsin digestion to produce peptides suitable for LC‑MS analysis.
- Peptide selection: Use of cysteine‑free marker peptides to avoid the need for protein reduction and simplify sample preparation.
- LC‑MS analysis: Chromatographic and mass spectrometric detection of marker peptides; the standard includes example LC‑MS conditions and chromatograms.
- Quantification procedures: Calculation of correction factors and blending ratios using marker peptide intensities; detailed formulas and worked examples are provided.
- Validation and reporting: Criteria for data validity, interlaboratory study results, and recommended test report contents.
Applications and users
- Textile testing and analytical laboratories performing fibre blend analysis, especially for high‑value fibres (cashmere, yak).
- Manufacturers and brands verifying material claims and preventing mislabelling or adulteration.
- Certification bodies, customs and regulatory agencies enforcing fibre content standards.
- Forensic and consumer protection organizations needing reliable species identification in processed textiles.
Related standards
- ISO 20418-1 - alternative LC‑MS method with protein reduction/extraction.
- ISO 1833 (all parts) - quantitative analysis of non‑animal fibres.
- ISO/TR 11827 - microscopic identification of hair fibres.
- ISO 17751 (all parts) - microscopical quantitative analysis when same‑species fibres are present.
Keywords: EN ISO 20418-3:2020, LC‑MS, peptide detection, proteomic analysis, textiles, animal hair fibres, cashmere authentication, fibre blend analysis, protein reduction.