Extraction of Theanine from Waste Liquid of Tea Polyphenol Production in Aqueous Two-phase Systems with Cationic and Anionic Surfactants

Extraction of theanine from waste liquid of tea polyphenol production was studied in aqueous surfactanttwo-phase system （ASTP） with cationic surfactant （CTAB） and anionic surfactant （SDS）. Results indicate that the region of ASTP is narrow and there is only a two-phase region of cationic surfactant. The increase in concentrations of NaBr and Na2SO4 are beneficial to the formation of ASTP. Theanine concentration in the bottom phase increases with increasing concentration of theanine, whereas the Partition coefficient and extraction rate only change a littlewhen the concentration of theanine is above 0.2 g.L-＇. With the increase of SDS concentration, the phase ratio and the partition coefficient decrease, while the extraction efficiency of theanine increases and the concentration of theanine changes a little in the range from 2.4/7.5 to 2.8/7.2 for SDS/CTAB ratio. The temperature has a notable ef- fect on the concentration of theanine in the bottom phase, partition coefficient and extraction rate of theanine. The increase of waste liquid decreases the phase ratio, increases the concentration and extraction rate of theanine in the bottom ohase, since the orotein and the saccharide enter the bottom nhase with theanine.

Ionic Liquid-salt Aqueous Two-phase System, a Novel System for theExtraction of Abused Drugs

A 1-butyl-3-methylimidazolium chloride-salt aqueous two-phase system was studied on extraction of abused drugs. The effects of sorts of salts, temperature, concentration of salt and drugs on system were investigated systematically. A satisfactory extraction efficiency of 93% was obtained for papaverine while that of morphine was 65%. The extraction mechanism was primarily discussed.

Extraction of Tetracycline via Ionic Liquid Two-phase System

A new method to extract and separate tetracycline（TC） in a new aqueous tyro-phase system（ATPS） consisting of hydrophilic [Bmim]BF4 and NaH2PO4 was investigated. The effects of the amount of salt, ionic liquid as well as tetracycline on extraction efficiency were studied systematically. The results show that ionic liquid-ATPS exhibited the highest extraction efficiency higher than 90%. When the concentration of NaH2PO4 was 33.3%--38.5% （mass fraction）, the amounts of ionic liquid and TC were 1.0--2.0 mL and 1.8 mL, respectively, and ionic liquid could be re-used.

COSMO-RS prediction and experimental verification of 1,5-pentanediamine extraction from aqueous solution by ionic liquids

1,5-Pentanediamine(PDA)produced by biological fermentation becomes popular,but the separation of PDA from the broth is a typical difficult problem.In this work,the performance of 200 ionic liquids(ILs),formed by combining 25 cations and 8 anions,in the extraction of PDA from aqueous solution were evaluated using COSMO-RS model.The extraction mechanism was investigated with the help ofσ-profile and interaction energy analyses.Both the cation and anion have impacts on the extraction efficiency,where cation mainly influences the interaction of IL with PDA and anion affects the hydrophobicity of IL.The IL composed of long alkyl-chain in cation and the anion of[PF6]-or[TF2 N]-,which has theσ-profile more likely distributed in the nonpolar region but less distributed in the polar region,is favorable for extraction.The experimental liquid-liquid equilibrium demonstrated the effects of cation and anion on extraction performance,which validated the reliability of COSMO-RS model in IL screening for PDA extraction.The IL[IM-1,8][PF6]could serve as a promising extractant for the downstream separation process of the biological production of PDA.

Phase Behavior of Ionic Liquids-Cesium Carbonate-Water Aqueous Two-phase Systems and Their Extraction of L-Tryptophan

Phase behavior and extraction ability of aqueous two-phase systems（ATPs） consisting of ionic liquids（ILs）, Cs2CO3 and water were investigated in this paper. Four kinds of ionic liquids, namely, 1-amyl-3-methylimidazolium bromide（[Csmim]Br）, 1-hexyl-3-methylimidazolium bromide（[C6nim]Br）, 1-heptyl-3-methylimidazolium bromide （[C7mim]Br） and 1-octyl-3-methylimidazolium bromide（[C8mim]Br）, were examined to discuss the influence of alkyl groups. Binodal curves and tie-lines at 288.15, 298.15 and 308.15 K were obtained. The partitioning behavior for L-tryptophan in such ATPs was further investigated. The effect of temperature, pH, Cs2CO3 concentration and the structure of ionic liquids on the partitioning were discussed in detail.

The phase behavior of n-ethylpyridinium tetrafluoroborate and sodium-based salts ATPS and its application in 2-chlorophenol extraction

In this paper,the aqueous two-phase systems(ATPS)containing n-ethylpyridinium tetrafluoroborate([EPy]BF_(4)),sodium-based salts,and water were studied and the extraction efficiency of 2-chlorophenol was measured to study the ATPS performance in extracting phenolic compounds.The binodal curves of[EPy]BF_(4)+sodium carbonate(Na_(2)CO_(3))ATPS and[EPy]BF_(4)+sodium dihydrogen phosphate(NaH_(2)PO_(4))ATPS have been determined at 308.15 K,318.15 K,and 328.15 K and atmospheric pressure.After getting good correlation with Merchuk equation,the binodal curves together with gravimetric method were used to calculate the tie-lines data.Furthermore,the reliability of tie-lines data was verified using Othmer-Tobias and Bancroft equations.Then,the salt influence and temperature influence on the phase behavior were discussed and the results show the salt-outing ability of Na_(2)CO_(3) is better than NaH_(2)PO_(4).With the aim of studying the ATPS performance in extracting phenolic compounds,extraction efficiency for 2-chlorophenol at different temperatures were studied and the results show that[EPy]BF_(4)+Na_(2)CO_(3) ATPS is preferred than[EPy]BF_(4)+NaH_(2)PO_(4) ATPS in applications.

Selective separation of protein and saccharides by ionic liquids aqueous two-phase systems

In the present work,it was found that aqueous solution of a hydrophilic ionic liquid (IL),1-butyl-3-methylimidazolium dicyanamide ([C4mim][N(CN)2]),could be separated into an aqueous two-phase system (ATPS) by inorganic salts such as K2HPO4 and K3PO4.The top phase is IL-rich,while the bottom phase is phosphate-rich.It was shown that 82.7%-100% bovine serum albumin (BSA) could be enriched into the top phase and almost quantitative saccharides (arabinose,glucose,sucrose,raffinose or dextran) were preferentially extracted into the bottom phase in a single-step extraction by [C4mim][N(CN)2] + K2HPO4 ATPS.The extraction efficiency of BSA from the aqueous saccharide solutions was influenced by the molecular structure of saccharides.The conductivity,dynamic light scattering (DLS) and transmission electron microscopy (TEM) were combined to investigate the microstructure of the IL-rich top phase and the possible mechanism for the selective separation.It is suggested that the formation of the IL aggregate and the IL aggregate-BSA complex plays a significant role in the separation of BSA from aqueous saccharide solutions.This is the first example for the selective separation by ILs-based ATPSs.It is expected that these findings would have potential applications in bio-analysis,separation,and IL recycle.

Recovery of natural active molecules using aqueous two-phase systems comprising of ionic liquids/deep eutectic solvents

Due to environmental protection requirements,extraction of bioactive compounds from plant materials using environment-friendly green solvents has always been a research hotspot.And great efforts of scholars have been made in this direction,as well as environment-friendly solvents have been used to develop many innovative extraction techniques.Ionic liquids(ILs)and deep eutectic solvents(DESs)are two kinds of typical designable green solvents,which are potential replacements for traditional volatile organic solvents used for extracting.Under the substances action of inorganic salts or polymers,ILs/DESs can form an aqueous two-phase system(ATPS),which has obvious advantages for separating natural products.This paper discussed the phase separation principle of ILs/DESs-based ATPSs and reviewed the applications in the extraction of natural active molecules in recent years,as well as to promote the development of separation of the active constituents in Chinese materia medica.

Efficient Purification of Camptothecin via Aqueous Two-phase System Composed of 1,1,3,3-Tetramethylguanidinium Benzoate Ionic Liquid and K2CO3

After being hydrolyzed into corresponding hydrosoluble carboxylate by 1,1,3,3,-tetramethylguanidine （TMG）, camptothecin was extracted via the aqueous two-phase systems composed of ionic liquid 1,1,3,3- tetramethylguanidinium（TMGM） carboxylate and K2CO3, and was regenerated at the final by dilute aqueous hy- drochloric acid. Among the ionic liquids, TMGM benzoate showed the best effect, TMGM formate the worst, this results were consistent with the liposolubilities of different carboxylic acid components in the ionic liquids. Through two-step extraction of TMGM benzoate ionic liquid/K2CO3 aqueous two-phase under a favorable condition, camptothecin was obtained in a purity of 98.3% and a total yield of 85.1%, from the crude camptothecin extract with a purity of 14.2%.