GC Optimisation for Compositional Assessment of Three Essential Oils

Abstract

Essential oils are complex mixtures of volatile compounds whose composition determines their characteristic properties and industrial applications. Their chemical profile may vary depending on geographical origin, plant material, cultivation system, extraction methods and storage conditions. This variability makes chromatographic analysis essential for the compositional assessment and differentiation of essential oils. This project focuses on the optimisation and application of GC–FID and GC–MS methodologies for the analysis of three essential oils of industrial interest in the Flavours & Fragrances sector: lavender, orange and clove essential oils. Eight lavender oil samples from Bulgaria and France, three orange oil samples from Brazil and four clove oil samples from Madagascar were analysed in order to identify compositional markers useful for chromatographic differentiation and compositional assessment. The optimised methods provided suitable separation and identification of the main compounds present in the analysed oils, demonstrating their applicability for essential oil compositional analysis and quality control. In lavender oils, the relationship between linalool and linalyl acetate represented one of the most relevant markers associated with compositional differentiation and ISO-related classification. Orange essential oils showed chromatographic profiles dominated by D-limonene, while aldehydes such as octanal and nonanal contributed to compositional differentiation between samples. In clove oils, differences between bud and leaf oils were mainly associated with variations in eugenyl acetate and β-caryophyllene relative abundances. Overall, the results obtained suggest that these compositional markers may constitute useful parameters for chromatographic differentiation and quality control of essential oils. Therefore, the methodologies developed in this study may provide a suitable basis for future analytical quality control strategies at Comercial Química Massó.