Ionic Liquid Aqueous Two-phase System Research Articles

Partitioning of Cephalexin in Ionic Liquid Aqueous Two‐Phase System Composed of 1‐Butyl‐3‐Methylimidazolium Tetrafluoroborate and ZnSO4

Ionic liquid aqueous two‐phase system (ILATPS) was applied in the extraction and separation of hydrosoluble antibiotics. The partitioning behavior of cephalexin (CEX) in 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([Bmim]BF4)‐ZnSO4 aqueous two‐phase system was studied by the partitioning parameter of the extraction efficiency. The effect of the volume of [Bmim]BF4, the concentration of ZnSO4, temperature, pH, and the volume of ZnSO4 solution was discussed concretely. When the volume of [Bmim]BF4 was 2 mL and the concentration of ZnSO4 was 35%, the extraction efficiency of CEX could reach 92.64% with pH unadjusted. The effect of the volume of [Bmim]BF4 on the extraction efficiency was higher than that of the concentration of ZnSO4. The temperature influenced not only the formation of aqueous two‐phase system but also the extraction efficiency of CEX. The target was found to be preferentially extracted to the [Bmim]BF4‐rich phase at the pH below 4.3. The partition of CEX to the top phase was enhanced by increasing the volume of [Bmim]BF4, the concentration of ZnSO4, and temperature; however, the partition of CEX to the top phase increased by decreasing the pH.

Simultaneous extraction and determination of sulfadiazine and sulfamethoxazole in water samples and aquaculture products using [Bmim]BF4/(NH4)3C6H5O7 aqueous two-phase system coupled with HPLC

An ionic liquid aqueous two-phase system (ILATPS) of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4)/ammonium citrate ((NH4)3C6H5O7) coupled with high-performance liquid chromatography was developed for the separation and determination of sulfadiazine (SD) and sulfamethoxazole (SMX) in water samples as well as aquaculture products. The effect of such parameters as the types and concentrations of salts, temperature, the concentrations of SD and SMX and the extraction time on the partitioning behavior expressed in terms of extraction efficiency has been evaluated. Under the optimal conditions, this extraction method has been successfully applied to the analysis of SD and SMX in water samples and aquaculture products with the recoveries of 98.29–99.55 % (SD) and 92.09–99.82 % (SMX). The detection limits for two analytes were 0.9 ng mL−1 (SD) and 1.8 ng mL−1 (SMX). In comparison with the traditional solvent extraction, ILATPS is much simpler and more environmentally friendly for the separation and enrichment of the sulfonamides antibiotics.

The Research for the Extraction of Yeast’S Nucleic Acid with [BMIM] BF<sub>4</sub>-H<sub>2</sub>O-KH<sub>2</sub>PO<sub>4</sub> Ionic Liquid Aqueous Two-Phase System

Construct ionic liquid - salt aqueous two-phase system for extracting yeast DNA. By using NaOH solution to process yeast, leaching the nucleic acid by ultrasonic assisting, variety of salts’ aqueous two-phase influence on the ionic liquid 1-butyl-3-methylimidazolium fluoroborate are discussed, and the influence of additive quantity of KH2PO4 and PH on the ionic liquid aqueous two-phase system for extraction of nucleic acid are studied. The result shows that process the yeast with 0.3% NaOH solution, assisted by ultrasound with power of 80W, temperature 60 °C, 3 hours’ extraction. KH2PO4take obvious advantage in the formation of ionic liquid aqueous two-phase system. In the process of extraction nucleic acid from [BMIM] BF4-H2O-KH2PO4aqueous two-phase process of nucleic acid, the best B-R buffer PH is 8.95, when the additive dosage of KH2PO4is 2.000g, A260/A280 in the supernatant is smaller than control group, the substratum which rich in ionic liquid contains more nucleic acid than the supernatant, and A260 in the supernatant is more than that in the control group. Therefore, we conclude that the ionic liquid aqueous two-phase has a relatively good effect in extraction of nucleic.

Design of environmentally friendly ionic liquid aqueous two-phase systems for the efficient and high activity extraction of proteins

Ionic liquids (ILs) have numerous applications in industrial processes as a benign alternative to conventional volatile organic solvents. However, many of them are toxic to organisms and are poorly biodegradable. In this work, a series of environmentally friendly cholinium ILs have been designed and synthesized. It was found that these ILs could form aqueous two-phase systems (ATPSs) with polypropylene glycol 400 (PPG400) which is thermo-sensitive, non-toxic and biodegradable. In order to understand the phase formation processes and possible application of these ATPSs for extraction/separation of proteins, the binodal curves and tie lines of these ATPSs were measured at 25 °C, and the effects of anionic structure of the ionic liquids, nature of the proteins and difference in the concentration of top- and bottom-phases on the partitioning behavior of some typical proteins were investigated systematically. It was shown that bovine serum albumin (BSA), trypsin, papain and lysozyme could be enriched effectively into the ionic liquid-rich phase of the ATPSs, and single-step extraction efficiency could be as high as 86.4–99.9% under the optimized conditions. Furthermore, enzyme activity of the native trypsin in water and in aqueous ionic liquid solutions was determined by using N-a-benzoyl-L-arginine ethyl ester as a substrate, and activity increases to about 127% was observed after 13 months storage. In addition, PPG400 has been recovered simply by heating and reused in the next extraction processes. This avoids the non-sustainable issue of highly salty water produced in the application of the polyethylene glycol (PEG) + salt and ionic liquid + salt ATPSs.

Separation/Richment Total Flavonoids in Phellinus Igniarius by Ionic Liquid/Salt Aqueous Two-phase Flotation

Ionic liquid/salt aqueous two-phase flotation coupled with UV spectrophotometry was developed for the separation/enrichment and analysis of total flavonoids in Phellinus igniarius(Sanghuang).The method was combined with ionic liquid aqueous two-phase system based on ionic liquid(1-butyl-3-methylimidazolium chloride,Cl) and inorganic salt(K2HPO4) with solvent sublation.The effect on the flotation efficiency was studied.The best conditions were as follows: the concentration of K2HPO4 was 50%;pH of solution was 9.53;the amount of Cl was 3 mL;the flotation time was 50 min;the nitrogen flow rate was 30 mL/min.The flotation efficiency was 85.31%,the enrichment factor was 8.59.These values are higher and larger than those of two-phase extraction.The method is suitable for the separation and enrichment of the active ingredient of Chinese medicine.

Effect of anionic structure on the phase formation and hydrophobicity of amino acid ionic liquids aqueous two-phase systems

Compared with the conventional ionic liquids, amino acid ionic liquids are more biodegradable and biocompatible, and can enhance stability of biomaterials. In this work, amino acid ionic liquids 1-butyl-3-methylimidazolium L-serine ([C(4)mim][Ser]), 1-butyl-3-methylimidazolium glycine ([C(4)mim][Gly]), 1-butyl-3-methylimidazolium L-alanine ([C(4)mim][Ala]) and 1-butyl-3-methylimidazolium L-leucine ([C(4)mim][Leu]) have been synthesized. These ionic liquids are found to form aqueous two-phase systems (ATPSs) by the salted-out of K(3)PO(4) in aqueous solutions. Phase diagram of the ATPSs and the Gibbs energies of transfer of methylene group from the bottom salt-rich phase to the top ionic liquid-rich phase have been determined at 298.15K and pH 14, and the effect of anionic structure of the ionic liquids on phase formation of the ATPSs and the relative hydrophobicity between the top and the bottom phases are then examined. In order to understand the effect of relative hydrophobicity of the phases in equilibrium in the ATPSs on the extraction/separation capability of biomolecules, the partition coefficients of cytochrome-c (as a model biomolecule) in the ATPSs are measured by spectrophotometry. It is suggested that hydrophobic interactions are mainly responsible for the higher partition coefficients of cytochrome-c in aqueous two-phase systems at pH 14, and the extraction and separation capacity of biomolecules can be improved by the modulation of the relative hydrophobicity of the phases and/or the pH of the system.

Determination of Trace Chlorophenols Endocrine Disrupting Chemicals in Water Sample Using [Bmim]BF4-NaH2PO4 Aqueous Two-Phase Extraction System Coupled with High Performance Liquid Chromatography

Abstract Determination of trace endocrine-disrupting chemicals such as chlorophenols in a water sample was carried out by utilizing ionic liquid aqueous two-phase extraction systems coupled with high-performance liquid chromatography (HPLC). In our study, the target analytes were 2,4-dichlorophenol (2,4-DCP), 2,6-dichlorophenol (2,6-DCP) and 4-chlorophenol (4-CP). The effects of salt concentration, pH value of aqueous phase, extraction time and the amount of ionic liquid on extraction efficiency were investigated. The highest extraction efficiency for these three target analytes were obtained as the concentrations of NaH 2 PO 4 aqueous, pH value, extraction time and the amount of ionic liquid were 0.5 g mL −1 , 4.0, 4 min and 2 mL, respectively. Ionic liquid phase was analyzed by HPLC directly with the detection limits of 2, 11 and 5 μg L −1 ( S/N = 3) for 2,4-DCP, 2,6-DCP and 4-CP, respectively. Good recovery results (90.2%–107.0%) with relative standard deviation ranging from 1.2% to 5.2% ( n = 5) were obtained when this method was applied to determine these three chlorophenols in tap water, lake water, waste water of chemical industry.

Separation, concentration and determination of chloramphenicol in environment and food using an ionic liquid/salt aqueous two-phase flotation system coupled with high-performance liquid chromatography

Ionic liquid–salt aqueous two-phase flotation (ILATPF) is a novel, green, non-toxic and sensitive samples pretreatment technique. ILATPF coupled with high-performance liquid chromatography (HPLC) was developed for the analysis of chloramphenicol, which combines ionic liquid aqueous two-phase system (ILATPS) based on imidazolium ionic liquid (1-butyl-3-methylimidazolium chloride, [C 4mim]Cl) and inorganic salt (K 2HPO 4) with solvent sublation. In ILATPF systems, phase behaviors of the ILATPF were studied for different types of ionic liquids and salts. The sublation efficiency of chloramphenicol in [C 4mim]Cl–K 2HPO 4 ILATPF was influenced by the types of salts, concentration of K 2HPO 4 in aqueous solution, solution pH, nitrogen flow rate, sublation time and the amount of [C 4mim]Cl. Under the optimum conditions, the average sublation efficiency is up to 98.5%. The mechanism of ILATPF contains two principal processes. One is the mechanism of IL–salt ILATPS formation, the other is solvent sublation. This method was practical when applied to the analysis of chloramphenicol in lake water, feed water, milk, and honey samples with the linear range of 0.5–500 ng mL −1. The method yielded limit of detection (LOD) of 0.1 ng mL −1 and limit of quantification (LOQ) of 0.3 ng mL −1. The recovery of CAP was 97.1–101.9% from aqueous samples of environmental and food samples by the proposed method. Compared with liquid–liquid extraction, solvent sublation and ionic liquid aqueous two-phase extraction, ILATPF can not only separate and concentrate chloramphenicol with high sublation efficiency, but also efficiently reduce the wastage of IL. This novel technique is much simpler and more environmentally friendly and is suggested to have important applications for the concentration and separation of other small biomolecules.

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.