Geographical and Seasonal Differentiation Along with Quality Evaluation of Lavender Essential Oil Through Volatile Profiling

The study aimed to characterize Romanian lavender essential oils (LEOs) according to geographical regions and harvested years by combining gas chromatography–mass spectrometry (GC/MS) with chemometric analysis and quality evaluation. Sixty-four LEO samples were collected from three Romanian areas (Moldova, Transylvania, Muntenia) during three consecutive years (2023–2025). GC–MS profiling identified 45 volatile compounds, with linalool, linalyl acetate, 1,8-cineole as predominant constituents. Oil quality was assessed using both a quality scoring algorithm based on characteristic volatile compounds and compliance with the ISO 3515:2002 standard. Most samples were classified as very good quality according to the proposed quality score, whereas only three samples fully complied with all ISO requirements. Pearson correlation analysis revealed significant positive associations among several biosynthetically related compounds, indicating identical variation within the volatile fingerprint. Linear discriminant analysis (LDA) successfully discriminated samples according to both geographical origin and harvest year, identifying characteristic combinations of volatile compounds responsible for sample classification. The results demonstrate that the overall volatile fingerprint, rather than individual compounds, provides a reliable basis for the authentication and differentiation of Romanian lavender essential oils. The combined GC–MS and chemometric approach represents an effective tool for quality evaluation, geographical traceability and authenticity assessment of lavender essential oils.