Standardizing Trypsin Digestion Parameters for Cashmere Identification
Standardized trypsin digestion at pH 8.2 and thirty-seven degrees for sixteen hours yields diagnostic peptides separating cashmere from wool by liquid chromatography.
Peptide Mass Fingerprinting
Analytical Technique
Advanced mass spectrometry methods identify animal species in premium fiber blends by analyzing specific protein fragments. For high-end garment imports, peptide mass fingerprinting is the definitive laboratory test used to confirm the presence of cashmere or yak. This biological assay provides an objective measure of composition that surpasses traditional optical microscopy.
Protein Extraction
The process begins with the enzymatic digestion of keratin proteins extracted from the fabric sample. Through this chemical breakdown, peptide mass fingerprinting generates a unique mixture of peptides that are characteristic of each animal species. This mixture is then analyzed to determine the exact mass of each constituent peptide.
Mass Spectrometry
The resulting spectrum of masses forms a distinct profile that is compared against a reference library of known animal proteomes. This digital library contains the genetic signatures of fibers from cashmere goats and merino sheep. By matching the observed peaks to these reference standards, the laboratory can detect even minor percentages of adulterants in high-value textile blends.
Database Matching
This method provides high sensitivity and works even when fibers have been heavily processed or dyed. This capability ensures that retail brands can confidently label their products without risk of misbranding penalties.