Physiological Enrichment
Evaporation of water from the leaves of the flax plant during growth leads to a higher concentration of heavier oxygen and hydrogen isotopes in the remaining plant water. This process of transpirational leaf water enrichment occurs at a rate determined by the local relative humidity and temperature of the agricultural region. The enriched water is used by the plant to synthesize cellulose, which incorporates this unique isotopic ratio directly into the flax fibers.
The isotopic ratio is therefore a signature of the local climate during the growing season.
Isotopic Trace
Measurement of the oxygen-eighteen and deuterium content in the cellulose of linen fibers provides a reliable method for determining where the flax was grown. Through the analysis of transpirational leaf water enrichment, laboratories can distinguish between flax grown in cool, humid coastal areas and flax grown in warm, dry inland regions. This testing is performed using isotope ratio mass spectrometry on samples of the raw fiber or finished yarn.
This method supports the verification of regional origin declarations in trade documents.
Climate Correlation
Historical weather data is compared with the isotopic results to verify the crop year of the flax. This comparison helps identify if older, stored fiber has been blended with the current harvest. The analysis is recorded in the mill’s raw material verification report.
