| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 167217 | Chinese Journal of Chemical Engineering | 2014 | 6 Pages |
Gas-assisted three-liquid-phase extraction (GATE), which has the advantages of both three-liquid-phase extraction and solvent sublation, is a novel separation technique for separation and concentration of two organic compounds into different phases in one step. This highly effective and economically applicable method has been developed for separating emodin and rhein from herbal extract. In a GATE system composed of butyl acetate/PEG4000/ammonium sulfate aqueous solution, influence of various parameters including gas flow rate, flotation time, salt concentration, initial volume of PEG and butyl acetate was investigated. Within 50 min of 30 ml·min− 1 nitrogen flow, removal ratio of emodin and rhein from aqueous phase could be over 99% and 97%, respectively. Mass fraction of emodin in the BA phase and rhein in the PEG phase could reach 97% and 95%, respectively. It is demonstrated that gas bubbling is effective for partitioning of emodin and rhein into butyl acetate and PEG phase respectively, and dispersed PEG and butyl acetate could be captured from the aqueous solution. Experimental results show that GATE could be an effective and economical technology for concentration and separation of co-existed products in medicinal plants.
Graphical abstractThe figure is schematic diagram of gas-assisted three-liquid-phase extraction system. The flotation column is made of glass, and is equipped with a G4 sintered glass sparger (pore size 3–4 μm). The inner diameter of the column is 36 mm and the length is 450 mm. There are three coexisting phases in the column, i.e. organic phase, polymer phase and aqueous phase (containing ammonium sulfate solution and simulated herbal exact). Three ports are open at different parts along the column to obtain samples of the three phases. In the process of gas bubbling, emodin and rhein initially contained in the aqueous phase are extracted into organic phase and polymer phase, respectively.Figure optionsDownload full-size imageDownload as PowerPoint slide
