Gas chromatography/mass spectrometry(GC-MS) analysis of the essential oil from Asarum by molecular distillation(MD) separation
The essential oil extracted from Asarum through steam distillation was fractionated using molecular distillation(MD). The crude essential oil was used for two molecular distillation processes. One residue(RF2) and two distillate fractions(DF1 and DF2) were prepared by MD. Three fractions were obtained under the operation parameters of 30°C and 5.0 mbar for the first process and 60°C and 5.0 mbar for the second process. The chemical components of different fractions were analyzed using gas chromatography/mass spectrometry(GC-MS). The results showed that the yields of DF1, DF2, and RF2 were 68.30%, 13.27%, and 15.95%(w/w), respectively. GC-MS results revealed that 35 ingredients were detected in the essential oil, including(+)-Limonene, α-Pinene, β-Pinene, Terpinen-4-ol, Eucalyptol, Terpinolene, and(-)-Carveol et al. Concentrations and compositions of these chemical components in different factions were significantly different. In conclusion, molecular distillation is a feasible separation method for essential oil.