ABSTRACT
Objective: To verify the feasibility of vapor-permeable membrane technology for the separation of water bodies containing essential oil of Asari Radix et Rhizoma (ARR) essential oil, and then to apply vapor permeate technology to the separation of more essential oils of traditional Chinese medicine. Methods: The polydimethylsiloxane/polyvinylidene fluoride (PDMS/PVDF) composite flat membrane and polyvinylidene fluoride (PVDF) flat membrane were collected as the membrane material. The oil-bearing water body of ARR volatile oil was separated by vapor permeate technology, and the oil penetration rate of two kinds of membranes was calculated. At the same time, the changes of the composition and content of the essential oil before and after the membrane were analyzed by gas chromatography-mass spectrometry (GC-MS). Results: The results showed that the essential oil penetration rate was significantly higher than that of PDMS/PVDF membrane when PVDF membrane was used as membrane material. GC-MS qualitative analysis results showed that the composition of the essential oil in the penetrants of the two membranes was basically the same as that of the essential oil obtained by the traditional steam distillation method. The content of α-pinene, β-pinene, 3,5-dimethoxytoluene, and methyl eugenol were determined by double internal standard method. The results showed that the content of each component in the PVDF membrane permeation was significantly higher than that of the PDMS/PVDF membrane permeation solution. Conclusion: It is feasible to separate the oil containing water from the essential oil of ARR by vapor permeation membrane technology. Compared with the PDMS/PVDF membrane, the PVDF membrane is more suitable for separating the oil containing water of the essential oil of ARR.
ABSTRACT
To investigate the feasibility of vapor permeation membrane technology in separating essential oil from oil-water extract by taking the Forsythia suspensa as an example. The polydimethylsiloxane/polyvinylidene fluoride (PDMS/PVDF) composite flat membrane and a polyvinylidene fluoride (PVDF) flat membrane was collected as the membrane material respectively. Two kinds of membrane osmotic liquids were collected by self-made vapor permeation device. The yield of essential oil separated and enriched from two kinds of membrane materials was calculated, and the microscopic changes of membrane materials were analyzed and compared. Meanwhile, gas chromatography-mass spectrometry (GC-MS) was used to compare and analyze the differences in chemical compositions of essential oil between traditional steam distillation, PVDF membrane enriched method and PDMS/PVDF membrane enriched method. The results showed that the yield of essential oil enriched by PVDF membrane was significantly higher than that of PDMS/PVDF membrane, and the GC-MS spectrum showed that the content of main compositions was higher than that of PDMS/PVDF membrane; The GC-MS spectra showed that the components of essential oil enriched by PVDF membrane were basically the same as those obtained by traditional steam distillation. The above results showed that vapor permeation membrane separation technology shall be feasible for the separation of Forsythia essential oil-bearing water body, and PVDF membrane was more suitable for separation and enrichment of Forsythia essential oil than PDMS/PVDF membrane.