Elemental Composition and Strontium Isotopic Ratio Analysis of Industrial Hemp (Cannabis sativa L.) for Textile Applications

Industrial hemp (Cannabis sativa L.) is increasingly valued as a sustainable raw material for textile applications, yet reliable analytical tools to characterize and trace its origin are still limited. This study presents a pilot investigation on the elemental composition and strontium isotopic ratio (Sr-87/Sr-86) of Italian industrial hemp samples, with the aim of evaluating their potential as chemical markers for geographic traceability. Hemp stalks and fibers collected from different Italian regions were finely ground, mineralized using microwave-assisted digestion, and analyzed by atomic absorption spectroscopy (AAS), inductively coupled-plasma mass spectrometry (ICP-MS), and multicollector ICP-MS (MC-ICP-MS). The analytical protocol was validated using certified reference materials, showing recoveries between 95.7% and 102.1%. The measured Sr-87/Sr-86 ratios ranged from 0.7085 to 0.7105, with consistent intra-sample reproducibility and values reflecting regional geochemical backgrounds. Elemental profiling revealed marked variability among samples, particularly Sr, Ca, Fe, and trace metals. Principal Component Analysis (PCA) indicated partial clustering according to geographical origin, distinguishing northern from southern Italian samples. Heavy-metal concentrations (Hg, Pb, Cd) were well below international textile safety thresholds, confirming the environmental sustainability of local hemp cultivation.