Effect of Different Parameters on Volatile Composition of the Different Parts of Cymbopogon schoenanthus L. Spreng (Poaceae) Extracted by Headspace Solid-phase Microextraction and Hydrodistillation

Abstract

In the present study, volatiles from different organs (leaves, roots, and spikelets) of Cymbopogon schoenanthus L. Spreng were investigated. The samples were collected from Oued Sbaa, El-Menia (Algeria) and analyzed for the first time by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). In addition to this green technique, cryogenic grinding using liquid nitrogen was performed on all samples to minimize the volatile loss. Results of HS-SPME (adsorption and affinity-based) were compared with those of essential oils extracted by hydrodistillation (heating-based) as a conventional extraction method and revealed remarkable variability. Findings showed also similarities in leaves and spikelets volatile mainly composed of monoterpene and sesquiterpene hydrocarbons; however, the volatile profile of the roots presented a specific composition dominated by sesquiterpene hydrocarbons and oxygenated sesquiterpenes. The effects of HS-SPME extraction parameters such as the temperature of headspace (45°C and 55°C), type of fiber coating (PDMS and PDMS/CAR), and the salting-out effect (sodium chloride at 20 %) were also studied. The results display that salt adding has considerably reduced the extraction efficiency of the analytes. Temperature presented two opposing effects on the composition. PDMS/CAR fiber revealed a great performance over PDMS. The multivariate statistical analysis including the hierarchical cluster analysis (HCA) and the principal component analysis (PCA) were used and showed many differences amongst the selected plant parts and the studied parameters. The results showed the possibility of HS-SPME-GC-MS application as a complementary tool for the characterization of the chemical composition of C. schoenanthus L. Spreng.