Mass Spectrometry SRM Calibration Protocols for Cashmere Wool Blends
Selected reaction monitoring mass spectrometry quantifies cashmere wool blends down to one percent using species-specific tryptic keratin peptides.
Tryptic Peptide Quantification
Proteolytic Measurement
Enzymatic digestion followed by mass spectrometric analysis of the resulting fragments represents the primary methodology for identifying the composition of animal hair fibers. Through tryptic peptide quantification, testing laboratories can accurately determine the weight ratio of cashmere to sheep wool in blended yarns. This analytical approach replaces the subjective and error-prone method of manual light microscopy.
Mass Differentiation
Trypsin cleaves the keratin proteins at specific amino acid sites, producing a mixture of short, stable peptides. In tryptic peptide quantification, the mass spectrometer measures the relative intensities of the species-specific peptide peaks. This comparison reveals the exact proportion of each fiber type present in the sample.
Trace Identification
Detecting and measuring low-abundance peptides allows for the identification of minor fiber blend components. For example, tryptic peptide quantification can reveal if a cashmere yarn has been adulterated with a small percentage of sheep wool. This sensitivity is crucial for maintaining the integrity of the supply chain.
Industrial Compliance
Quality control departments in the apparel industry rely on these precise measurements to verify the authenticity of their textile imports. Utilizing tryptic peptide quantification provides the necessary data to support product labels and comply with consumer protection laws. This testing protects brands from the reputational damage associated with mislabeled products.
It also assures retailers that the expensive garments they buy meet the high standards expected by their customers.