Optimization by experimental design of headspace sorptive extraction and solid-phase microextraction for the determination of terpenes in spices

Headspace sorptive extraction (HSSE) was compared with solid-phase microextraction (SPME), a reference method for the extraction of volatiles. HSSE and SPME were optimized by experimental design for the extraction of terpenes and terpenoids from spices. The different extraction parameters studied were the extraction time, the extraction temperature, the sample mass, and the equilibrium time (only for SPME). Extracts were obtained by HSSE and SPME from six spices: cinnamon, cumin, thyme, fennel seeds, nutmeg, and clove. Those extracts were analyzed by gas chromatography coupled to a mass spectrometer (GC-MS) qualitatively and quantitatively. The quantitative analysis was conducted using 28 standards. For each standard, calibration curves, limits of detection (LOD) and quantification (LOQ) were determined. The study shows that HSSE is selective, sensitive, and highly repeatable method for the extraction of volatile terpenes and terpenoids from spices and allows to produce extracts concentrated in the μg/g range of terpenes.