The solvent extraction separation of lithium isotopes has become of growing interest due to the need for 6 Li and 7 Li isotopes in the nuclear industry. A one-step synthesis of room temperature ionic liquid with low viscosity 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIm][NTf 2 ]) (with reaction yields of 87.47%) was used by the ultrasonic method. The addition of ionic liquid [EMIm][NTf 2 ] in the system significantly improved the extraction efficiency and separation factor compared to the traditional organic solvent anisole for extraction separation of lithium isotopes. The distribution ratio increased from 0.00145 (with the single stage separation factor of 1.024 ± 0.001) to 0.134 (with the single stage separation factor of 1.034 ± 0.001). Furthermore, a multi-stage extraction process was intended to enhance lithium isotope separation performance. Each stage of stripping can be considered as an extraction separation equilibrium process, in which the strip liquor from the load organic phase is used for separation in the next stage as the “original aqueous solution”. The abundance of 6 Li + gradually improved with an increase in the extraction stages. The relative abundance of 6 Li + increased by 1.492% at the 20-stage extraction separation (from 7.53% to 9.022%). This new and simple approach (stripping cross-flow multistage method (SCFM)) was to achieve large enrichment of lighter isotopes of lithium ( 6 Li + ) by combined extraction and stripping process. In summary, the present study offers the possibility for the enrichment of 6 Li + during lithium isotope extraction separation.
Enantioselective extraction of esmolol (ES) enantiomers was performed with tartaric acid derivatives and boric acid (BA) as chiral extractant. The single–stage extraction experiments were carried out to construct the extraction system for ES enantiomers through investigating type of tartaric acid derivatives, type of the organic solvent and temperature. The optimal conditions for extraction system were achieved, which involves 1,2–dichloroethane as organic solvent, iso–butyl–D–tartrate (DT) as chiral selector and 278 K for extraction temperature. A single–stage extraction model was established based on an interfacial reaction mechanism and proved to be reliable by verified experiments. Based on the single–stage extraction model and the law of mass conservation, a fractional extraction model was explored to simulate and optimize the fractional extraction process. The optimal operation conditions at temperature of 278 K were obtained including ES concentration of 0.01 mol/L, DT and BA concentrations of 0.1 mol/L, F/W of 0.25 and O/W of 1.0347, feeding in the middle stage at pH of 5.50. The ee eq of 0.98 and Y eq of 0.99 can be achieved by symmetric separation with the number of stages of 32 under the optimal conditions. As S–ES is the desired product, 10 stages are enough to obtain 0.98 of ee raffinate for S–ES by asymmetric separation under the conditions containing ES concentration of 0.01 mol/L, DT and BA concentrations of 0.1 mol/L, F/W of 0.25 and O/W of 1.64, feeding in the Stage 2 at pH of 5.50.
3,4-Dihydroxybenzaldehyde (DHB) is a highly effective water-soluble compound in the traditional Chinese medicine Salvia miltiorrhiza Bge. Which demonstrates clear therapeutic effects against a variety of diseases. Therefore, the development of a selective approach for the separation of 3,4-dihydroxybenzaldehyde is of great significance. In this study, electro-driven extraction combined with multi-stage extraction technology was employed for the first time to separate 3,4-dihydroxybenzaldehyde from S. miltiorrhiza Bge. Decoction (Recovery ≥ 46.09%). Five long-chain fatty alcohols were selected as the supported liquid membrane (SLM) in the electro-driven extraction. Factors influencing extraction efficiency, including pH, voltage, and extraction time, were optimized using a design of experiments. Under the optimal conditions, the linearity of 3,4-dihydroxybenzaldehyde ranged from 0.01 to 100 μg·mL−1), with limits of detection (LOD) and quantification (LOQ) of 5 and 17 ng·mL−1, respectively. The precision of electro-driven liquid membrane extraction for 3,4-dihydroxybenzaldehyde was below 8.42%. This paper reports novel electro-driven liquid membrane extraction for selectively isolating 3,4-dihydroxybenzaldehyde from S. miltiorrhiza Bge.
危险品化学品经营许可证（带存储）