Comparison of headspace solid-phase microextraction, headspace single-drop microextraction and hydrodistillation for chemical screening of volatiles in Myrtus communis L.

Headspace solid-phase microextraction (HS-SPME) and headspace single-drop microextraction (HS-SDME) methods have never been used for the extraction and analysis of the volatile compounds of Myrtus communis. For that reason, in this work, these two techniques were compared with the traditional hydrodistillation (HD) extraction technique. To compare SPME and SDME with HD for the extraction and analysis of Myrtus communis volatiles. Three extraction methods, i.e. SPME, SDME and HD, coupled to gas chromatography-mass spectrometry were used and optimised for the analysis of Myrtus communis volatiles. The SPME extraction was performed on a 100 µm PDMS fibre and for SDME a drop of n-octadecane containing 0.7% of menthol as internal standard was used as extracting solvent. The results were compared from different viewpoints including efficiency of extraction, different kinds of species extracted and quantity of extracted compounds with HD. The main analytes extracted by SPME were found to be α-pinene, limonene, 1,8-cineole, linalool, linalyl acetate, α-terpinyl acetate and geranyl acetate, whereas for SDME α-pinene, limonene, 1,8-cineole, linalool, linalyl acetate and β-myrcene were extracted as major components. Hydrodistillation could extract α-pinene, limonene, 1,8-cineole, linalool, α-terpineol, linalyl acetate, α-terpinyl acetate, geranyl acetate and cis-isoeugenol better than other volatiles from Myrtus communis. The results demonstrated that HS-SPME and HS-SDME can be applied successfully for the extraction and separation of volatiles in aromatic plants, and these techniques are easier to perform, and more effective than HD for collection of more volatile compounds.