Analysis of the volatile compounds inNepeta crispawilld. Using improved HS-SPME-GC-MS and comparison with conventional methods

Abstract

In this study, gas chromatography-mass spectrometry (GC-MS) following microwave distillation and solid-phase microextraction (MD-SPME) was developed for the analysis of essential oil compounds in Nepeta crispa. To improve the headspace (HS) method, microwave powers, irradiation times, and SPME fiber coatings were studied. The optimal experiment parameters obtained were 65-μm PDMS/DVB SPME fiber, a microwave power of 400 W, and an irradiation time of 3 min. MD-SPME was compared with headspace solid-phase microextraction (HS-SPME) and conventional hydrodistillation (HD) for the extraction of essential oil compounds in N. crispa. A comparative qualitative and quantitative study on the composition of the oils was carried out. For this, 26 compounds, constituting 98.2% of the oil, were identified in the essential oil by MD-SPME, and 23 compounds, representing 91.3% of the oil, were characterized in the SPME and HD methods; 25 compounds, constituting 94.6% of the oil, were separated and identified. The main compounds identified by all methods were 1,8-cineol, β-bourbonene, α-terpineol, and β-pinene. The relative standard deviation (RSD) values of less than 8% show that the MD-SPME method has good repeatability.It has been shown that the extraction of essential oils from N. crispa with MD-SPME was better in terms of energy saving, extraction time, plant material, oxygenated fractions, and product quality.

Chemical composition and antinociceptive activity of volatile fractions of the aerial parts of Solidago chilensis (Compositae)

“…Medicinal plants in post-harvest processing should be dried between 30 and 60 o C, and medicinal plants containing essential oils should be dried at temperatures below 40 o C (Azar et al 2012). Aerial parts of S. chilensis were dried in electric oven inflated at 37 o C with air velocity of 0.45 m/s and relative humidity not exceeding 30%, for 48 hours.…”

Volatile compositions and glandular trichomes of Zataria multiflora in different phenological stages under normal and drought stress conditions

“…This technique is widely used to identify the volatile compounds in particular aromatic and medicinal plants [12]. The most common extraction technique used to obtain essential oil from aromatic plants is conventional hydrodistillation [13]. In the headspace method, volatile compounds from solid or liquid matter are separated by gas chromatography and it was used preferably for samples that cannot be injected into the machine, including fresh or dried tissue of plants, in cases where the sample amount is low [14].…”

GC-MS analysis and comparison of volatile compounds ofSalvia aucheriBoiss. var.mesatlanticaMaire., obtained by hydrodistillation and headspace solid phase microextraction (HS-SPME)

“…Compared with HD, headspace-solid phase microextraction (HS-SPME) is a simple, sensitive, and solvent-free sampling and concentration technique. Combined with gas chromatography-mass spectrometry (GC-MS), HS-SPME can be used for the analysis of volatile components of natural products and foods [3,4]. In SPME, analytes are adsorbed from a solid sample by headspace extraction, using a polymer-coated fused silica fiber.…”