Headspace solid-phase microextraction-gas chromatography--mass spectrometry analysis of the volatile compounds of Evodia species fruits

In this study the investigation of the aroma compounds of dried fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e. E. officinalis Dode) (Rutaceae family) was carried out to identify the odorous target components responsible for the characteristic aroma of these valuable natural products. To avoid the traditional and more time-consuming hydrodistillation, the analyses were carried out by means of headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The SPME headspace volatiles were collected using a divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber. The extraction conditions were optimized using a response surface experimental design to analyze the effect of three factors: extraction temperature, equilibrium time and extraction time. The best response was obtained when the extraction temperature was around 80 degrees C, equilibrium time near 25 min and extraction time close to 18 min. Analyses were performed by GC-MS with a 5% diphenyl-95% dimethyl polysiloxane (30 m x 0.25 mm I.D., film thickness 0.25 microm) capillary column using He as the carrier gas and a programmed temperature run. The main components of the HS-SPME samples of E. rutaecarpa (concentration >3.0%) were limonene (33.79%), beta-elemene (10.78%), linalool (8.15%), myrcene (5.83%), valencene (4.73%), beta-caryophyllene (4.62%), linalyl acetate (4.13%) and alpha-terpineol (3.99%). As for E. officinalis, the major compounds were myrcene (32.79%), limonene (18.36%), beta-caryophyllene (9.92%), trans-beta-ocimene (6.04%), linalool (5.88%), beta-elemene (7.85%) and valencene (4.62%).