替考拉宁在不同液液萃取体系中分配系数的测定

Teicoplanin is one of the macrocyclic glycopeptide antibiotics, which is active against Gram-positive bacteria, and has attracted a lot of attention in the field of chiral separation recently. In this work, the partition coefficients and extraction ratio of teicoplanin in three different solvent systems were studied: conventional extraction, reactive extraction and reverse micelle extraction. With conventional solvent extraction, n-butanol demonstrated high partition coefficient for teicoplanin, but low extraction ratio because of its high solubility in water. Reactive extraction of teicoplanin showed the highest partition coefficient with almost 100% recovery in organic phase when tri-n-octylmethyl ammonium chloride (TOMAC) was used as extractant and pH value was above 5.0. A reverse micelle system, consisted of isooctane 10 mmol-L^-1 TOMAC -t-1% n-octanol, also offered high separation factor for teicoplanin. The results are beneficial for the design of teicoplanin separation and purification process.     

Partition Behavior of Penicillin in Three-liquid-phase Extraction System

Partition behavior of penicillins G and V was studied in a novel three-liquid-phase extraction system, which is composed of butyl acetate (BA), polyethylene glycol (PEG), ammonia sulfate [(NH4)2SO4] and water (H2O). The main components in the top, middle and bottom phases are butyl acetate, polyethylene glycol aqueous solution and ammonia sulfate aqueous solution, respectively. Some parameters such as partition coefficients Di/j and mass fractions Ei of penicillins G and V were determined at the room temperature, respectively. Experimental efforts have been made to investigate the partition behavior of penicillin in the three-liquid-phase extraction system, including initial concentrations of phase-forming components [PEG and (NH4)2SO4], PEG molecular weight, pH, initial concentration of penicillin. The results indicated that penicillins G and V have the similar partition behavior. They preferentially distribute into the middle phase with the increase of initial concentration of phase-forming components and into the top phase with the decrease of pH, while partition coefficient Dm/b is hardly affected by pH value. The variation of PEG molecular weight has little effect on mass fractions of penicillin. The increase of initial concentration of penicillins G and V could lead to the increase of Dt/b, Dm/b and the decrease of Dt/m, while their mass fractions in all phases were almost independent on their initial concentrations.     

HNPC-A9908正辛醇/水分配系数的测定

采用摇瓶法,对HNPC-A9908[O-(3-苯氧苄基)-2-甲硫基-1-(4-氯苯基)丙基酮肟醚]这一新的非酯肟醚类拟除虫菊酯杀虫剂在醇/水体系中的分配系数的测定。测定结果表明,在25℃条件下,振荡5￣7h可达到平衡,分配系数平均为5.00。     

COSMO‐RS Calculations of Partition Coefficients: Different Tools for Conformation Search

This work is encouraged by the growing interest and recent success of quantum mechanics‐based methods in modeling of thermodynamic properties in the field of chemical engineering and life sciences. Among those, the COSMO‐RS model has become one of the most popular methods to predict phase equilibria in complex bio‐related systems. Recently, we have shown that the quality of predictions of n‐octanol/water and micelle/water partition coefficients is improved when the weighted mixtures of conformers are used to represent molecules, thereby demanding that the conformation analysis is performed for each component of the system. In this paper, different methods for performing the conformational search are evaluated. Micelle/water partition coefficients of solutes from different homologous series in aqueous solutions of Triton X100 as well as the n‐octanol/water partitioning of three common drugs (aminopinicillanic acid, ampicillin, and penicillin G) are calculated and compared with experimental data. Conformational analysis is made by the HyperChem program for the molecules placed in vacuum as well as by using the molecular dynamics simulation in a solvent medium (n‐octanol and water). It is demonstrated that molecular dynamics simulation is a promising tool to conduct conformational analysis. Along with the possibility of providing the conformers for large surfactant and pharmaceutical molecules, the method accounts for the solvent in a realistic manner. The results for micelle/water partition coefficients illustrate that n‐octanol is a reasonable approximation for the “micelle‐like” medium in molecular dynamics (MD) simulations. Predicted n‐octanol/water partition coefficients of three penicillins are in a good agreement with literature data and values calculated by a common quantitative structure‐activity relationship (QSAR).     

病毒星表观油水分配系数的测定

[目的]在建立水中病毒星的残留分析方法的基础上,测定病毒星在正辛醇-水中的表观油水分配系数.[方法]采用HPLC法测定病毒星的质量浓度,用摇瓶法测定病毒星在正辛醇-水中的表观油水分配系数.[结果]病毒星在0.05、0.11、1.13 mg/kg质量分数下的平均添加回收率为98.3％、98.4％、91.5％,变异系数为2.2％～3.9％.[结论]摇瓶法测得病毒星在二次蒸馏水中的平均lgK.w为3.08.     

一种新型的蛋白质分离技术——反胶团萃取

本文综述了反胶团特点、萃取蛋白质的原理、方法及应用。     

Partition Coefficients of Alkyl Parabens and Ibuprofen in Micellar Systems

The partitioning of alkyl parabens and ibuprofen in aqueous solutions of nonionic and ionic surfactants is studied experimentally and via a priori predictions using the COSMO‐RS model. The effects of organic (Bu₄NBr) and inorganic (NaCl) electrolytes are examined. Addition of NaCl results in a slight increase in the partition coefficients of parabens in solutions of octylphenolpoly(ethyleneglycolether) and a more pronounced increase in the sodium dodecyl sulfate (SDS) system. The partition coefficients of ibuprofen increase on addition of NaCl to aqueous solutions of SDS and decrease if Bu₄NBr is added to dodecyl trimethyl ammonium bromide (DTAB) solutions. Good agreement between experimental and calculated data shows a high potential of COSMO‐RS in the prediction of micelle/water partition coefficients in the presence of electrolytes and makes it a valuable tool in drug and drug‐carrier design as well as in optimizing micellar reactions or micelle‐enhanced separation processes.     

草铵膦的正辛醇/水分配系数的测定

[方法]采用摇瓶法测定草铵膦的正辛醇/水分配系数,并用萃取法对有机相中的草铵膦进行浓缩、反相液相色谱法分别对两相中的草铵膦进行测定.[结果]萃取法的回收率为95.2％～99.3％,方法的变异系数为1.69％Ⅰ[结论]方法的精密度较高,具有简便、快速的优点,适用于草铵膦的正辛醇/水分配系数测定.     

Liquid-Liquid Extraction of Acids by a Malonamide: II-Anion Specific Effects in the Aggregate-Enhanced Extraction Isotherms

Non-electrostatic ion-specific effects are strong for anions when water is involved. We study here the thermodynamic equilibrium of a water-in-oil microemulsion stabilized by a surface-active extractant in a Winsor-II regime. Acid extraction isotherms for different anions located differently in the Hofmeister series have been investigated. A Langmuir like model was written for the specific case of acids treated as electrolytes, describing acid extraction as the adsorption of extracted electrolytes on the polar/apolar interface of the aggregates. Except for sulfate, isotherms can be described at first approximation as simple Langmuir-type isotherms when plotted as a function of the acid activity in the aqueous phase. The validity of the model being hence demonstrated, acid extraction free energies could be derived and compared, taking into account the effect of the anion position in the Hofmeister series. The case of phosphate, chloride, and sulfate as kosmotropes can be distinguished. They are significantly extracted, only above a threshold since the sphere-to-rod transition of the reverse aggregates has to be triggered by high chemical potential of the acid required to compensate anion dehydration.     

不同强化方法对超临界CO2萃取人参皂甙的影响

为改善超临界CO2在萃取极性物质和传质方面的缺点,用自行设计的超声强化超临界CO2萃取设备,研究了夹带剂、超声和反相微乳技术对超临界CO2萃取人参皂甙的强化效果。实验条件设定为:萃取压力、温度与时间分别为25 MPa、45℃、4 h,CO2流量为2.0 L/h,分离压力与温度分别为6 MPa和55℃,超声频率、功率密度和辐照方式分别为20 kHz、100 W/L和6 s/6 s。实验结果发现,超声联合超临界CO2反相微乳萃取的人参皂甙萃取率分别是SC、MSC、UMSC和SCRM的13.9、4.9、3.1和1.8倍,其萃取固形物中皂甙的质量分数分别是SC和MSC的4.5和2.1倍;MSC、UMSC、SCRM和USCRM的人参皂甙萃取速率大小顺序依次为:USCRM>SCRM>UMSC>MSC;超声的加入不会改变对萃取人参皂甙的选择性和人参皂甙的结构。     

一个物理化学设计实验的探讨与改进——离子液体溶液平均活度系数的测定

文章制备了溴化1-十二烷基-3-甲基咪唑[C12mim]Br和1-十二烷基-3-甲基咪唑四氟硼酸盐[C12mim][BF4]两种离子液体。在不同温度下,测定了两种离子液体水溶液的电导率,根据电导率-浓度曲线转折点求出了两种离子液体水溶液的临界胶束浓度。由Debye-Hücker和Osager-Falk-enhangen公式计算出离子液体的平均活度系数。结果表明：[C12mim]Br和[C12mim][BF4]的水溶液临界胶束分别为5.75×10-3 mol·L-1和6.00×10？3 mol·L-1。25℃下,平均活度系数随浓度的增大而降低。     

反相高效液相色谱法测定酚类化合物的正辛醇/水分配系数

应用反相高效液相色谱法测定了几种酚类化合物的正辛醇/水分配系数(Kow),建立了容量因子(k’)与Kow的关系方程,考察了标样化合物结构对测定结果的影响。实验结果表明,反相高效液相色谱法是一种有效测定物质Kow的方法,且标样化合物的结构对测定结果有较大影响,方程logKow=1.647403 logk’+3.292482(R=0.98)较方程logKow=2.042692 logk’+3.298356(R=0.94)对待测物有更好的预测能力,可使logKow值与文献值的平均偏差由0.397降低为0.23。     

The Kinetics of Droplet Sedimentation in Liquid-Liquid Extraction

Liquid-liquid extraction is a major separation process in chemical industry. Beside appropriate design of mass transfer equipment, successful design of phase separation equipment is an important issue. Therefore, the separation of liquid-liquid dispersions was investigated and modeled with kinetic approaches to gain information for settler design. A modified first-order sedimentation rate model, a first-order consecutive step rate model, and a mixed-order rate model were applied and compared to the experimental data. The advantage of kinetic modeling of the rate of sedimentation, specifically addressing the impact of viscosity and electrolyte concentration, was successfully demonstrated.     

Removal of Cu2+ from Water Using Liquid-Liquid Microchannel Extraction

The very good extraction selectivity of Cu²⁺ from water was demonstrated with a new microchannel equipment, by employing di-(2-ethylhexyl)phosphoric acid (D2EHPA) as an extractant and kerosene as a solvent. The effects of different experimental parameters on the extraction efficiency E, the volumetric mass transfer coefficient K_La, and the entrainment were experimentally investigated. The results showed that the extraction efficiency increased with increasing temperature, extractant concentration, phase ratio (organic/aqueous), and pH. The total flow rate, phase ratio, and pH were found to have a great effect on the mass transfer, whereas the temperature and the extractant concentration showed little effect.     

Investigation of Three-liquid-phase Extraction Systems for Simultaneous Separation of Emodin and Rhein

Several three-liquid-phase extraction systems comprised of organic extractant,polymer and salt aqueous solution were applied to isolate and purify simulated herbal extract containing emodin and rhein.Some influential factors on the partitioning behaviors were studied.The results revealed that extractant type and solution pH value were crucial factors for improving the separation performance.The optimal separation results were obtained at pH 8.00 with methyl isobutyl ketone as the extractant,10%（ω） polyethylene glycol with the molecular weight 4000 Da,and 10%（ω） ammonium sulphate.Under the optimized conditions,95%emodin and 97%rhein were simultaneously extracted into the organic phase and polymer-rich phase from simulated herbal solution with the initial concentration of 100×l0^-6（ω）,respectively,and their separation factor of over 10000 was achieved.By adjusting pH value,back extraction rate of both emodin and rhein could be up to about 99%.With the assistance of molecular simulation program XLOGP3 and molecular orbital package,the possible mechanism of extraction was analyzed,and hydrophobic interaction and hydrogen-bonding interaction might be the major driving forces affecting the partitioning behaviors of emodin and rhein.     

苯酚羟化液萃取脱水的液液相平衡数据的测定

本文研究了异丙醚和甲基异丁基甲酮作为苯酚羟化液萃取脱水剂在20℃时的液-液相平衡关系。采用浊度法和色谱法相结合的策略测定了体系的相平衡曲线,并绘制了三元相图：从三元相图的平衡曲线看,所用萃取剂具有较好的萃取性能。     

Overview of Innovative Technologies in Liquid-Liquid Extraction Regarding Flexibility

As a result of increasing market volatility and product diversification the technology requirements will change in the future. Flexibility needs to be increased, enabling a large operating window while maintaining intensive mass and energy transfer and resource-efficiency. A promising approach is using innovative small-scale technologies. To assess flexibility, the technologies must be characterized in a wide range of operating parameters and physical properties. Therefore, research work on innovative technologies for liquid-liquid extraction is presented.     

囊泡、微乳和胶束有序体系中纳米无机矿物的生长及其在生物矿化领域的应用前景

综述了在囊泡、微乳、胶束和反胶束等有序体系中纳米无机矿物如草酸钙、磷酸钙等的生长及其影响因素。讨论了其在生物矿化领域的应用前景     

Partition coefficients for fatty acid esters in supercritical fluid CO2 with and without ethanol

The complex nature of fish oils was exploited to study the dependence of structural factors upon fatty acid ester solubility in supercritical fluid carbon dioxide (SCF-CO₂). Partition coefficients were determined for a number of components present in two mixtures of fatty cid ethyl esters derived from menhaden oil in SCF-CO₂ at 60°C and 125 bar. Analogous data also were obtained for SCF-CO₂ with 5% (w/w) ethanol added. The addition of ethanol was found to increase partition coefficients for all species, but resulted in a decrease of fluid selectivity. Aside from the chain length of a component, both the degree and position of unsaturation were found to be structural factors that affect the value of the partition coefficient.     

离子液体及其在萃取中的应用研究进展

环境问题日益成为人们关注的焦点,离子液体作为一种绿色溶剂可以较好的解决原有的挥发性有机溶剂造成的环境污染问题。综述了室温离子液体的研究情况以及它在液液萃取中的应用进展。