高效液相色谱手性流动相添加剂法拆分氯噻酮对映体

应用反向高效液相色谱,以羟丙基-β-环糊精(HP--βCD)作为手性流动相添加剂,拆分了氯噻酮(Chlorthalidone)对映体。对主要的影响因素如羟丙基-β-环糊精浓度、流动相pH值、三乙胺(TEA)、甲醇、柱温、流速等进行了系统研究,建立了羟丙基-β-环糊精流动相添加剂法拆分氯噻酮对映体的方法。使用HarbonLichrospher-C18色谱柱(5μm,150 mm×4.6 mm),流动相为V(甲醇)∶V(水相)=20∶80(水相含30 mmol/L HP--βCD0、.1 mol/L Na2HPO4、体积分数2%的TEA、pH5),流速为0.8 mL/min,室温下拆分,氯噻酮对映体可得到良好分离。     

四-(4-磺基苯)卟啉与环糊精超分子体系的电化学研究

以电化学方法研究了水溶性卟啉四-(4-磺基苯)卟啉(简称TPPS4)与两种环糊精羟丙基-α-环糊精(简称HP--αCD)、羟丙基-γ-环糊精(简称HP--γCD)的相互作用形成的超分子体系,结果表明TPPS4与HP--αCD、HP--γCD分别形成了1∶1、1∶2的包结物,它们的包结常数分别为8.78×103L/mol、4.58×109L2.mol-2。     

毛细管区带电泳对手性药物盐酸美西律和盐酸异博定的对映体分离

应用环糊精-毛细管区带电泳体系对手性药物盐酸美西律和盐酸异博定的对映体分离进行了研究。结果表明, 在所研究的手性选择剂α-环糊精, β-环糊精, 二甲基-β-环糊精, 羟丙基β-环糊精和γ-环糊精中, 羟丙基β-环糊精对所研究的手性药物分离效果较好。对盐酸美西律和盐酸异博定的最佳羟丙基-β-环糊精浓度分别为30mmol/L和9mmol/L, 最佳缓冲溶液浓度为100mmol/L Tris-H3PO4(pH2.3)。向缓冲溶液中加入0.05%羟丙基纤维素(HPLC)可改善分离。盐酸美西律获得了接近基线的手性分离, 而盐酸异博定亦获得了较好的分离。     

以羟丙基-β-环糊精为手性添加剂拆分2-取代芳基丙酸:取代基对手性识别的影响（英文）

以羟丙基-β-环糊精为手性添加剂,采用反相高效液相色谱法对2-取代芳基丙酸类物质进行了手性拆分。考察了流动相的组成,包括缓冲溶液、有机改性剂以及添加剂的浓度等。缓冲溶液的pH值、有机改性剂的种类与浓度,以及添加剂的浓度对色谱峰的保留时间和分离度均有较大的影响。以YMC ODS-C_(18)(150 mm×4.6 mm,5μm)为色谱柱,乙腈-0.10 mol/L磷酸盐缓冲液(pH 3.3,含25 mmol/L添加剂)为流动相,测定了各2-取代芳基丙酸与羟丙基-β-环糊精的包结常数,考察了羟丙基-β-环糊精对各物质的包结形式。实验结果表明,羟丙基-β-环糊精与各对映体均以1∶1的形式包结,同时发现推电子取代基更有利于羟丙基-β-环糊精的包结行为,为羟丙基-β-环糊精对手性拆分的影响提供了一个有利的参考因素。     

毛细管电泳拆分苯磺酸氨氯地平及机理的探讨

采用羟丙基-β-环糊精(HP-β—CD)作为手性选择试剂对外消旋的苯磺酸氨氯地平进行了拆分,研究了环糊精种类,浓度,缓冲液的pH值以及添加剂对分离的影响,结果表明以羟丙基-β-环糊精为手性选择剂,短链的阳离子表面活性剂四乙基氯化铵为电渗流改性剂可以使苯磺酸氨氯地平实现基线分离,对拆分的机理进行了探讨。     

原料配比对羟丙基-β-环糊精取代度的影响

以β-环糊精、氢氧化钠和环氧丙烷为原料,通过改变原料配比合成了不同取代度的羟丙基-β-环糊精(HP--βCD).利用1H NMR对样品进行了表征,进而计算了产物的取代度.结果表明,当固定β-环糊精与氢氧化钠用量摩尔比为1∶6,且环氧丙烷用量低于18倍的β-环糊精用量时,HP--βCD的取代度随环氧丙烷用量的增加呈现规律性增加,有利于获得所需取代度的HP--βCD.     

相溶解度法研究不同环糊精对蛇床子素的增溶作用

通过测定蛇床子素(OST)在不同浓度的β-环糊精(-βCD)、羟丙基-β-环糊精(HP--βCD)、甲基-β-环糊精(M--βCD)中的溶解度,绘制出蛇床子素的相溶解度曲线,得到蛇床子素在三种环糊精中的相溶解度曲线均为AL型,说明蛇床子素与环糊精以1∶1包合,其表观结合常数分别为296.0 L.mol-14、41.8 L.mol-1、397.9 L.mol-1。实验结果表明,羟丙基-β-环糊精、甲基-β-环糊精对蛇床子素的增溶作用要优于β-环糊精。     

鼠血中烯丙洛尔对映体的毛细管电泳分离与测定

建立了一种双手性拆分试剂(羟丙基-β-环糊精和羧甲基-β-环糊精)拆分烯丙洛尔对映体的毛细管电泳方法。烯丙洛尔对映体在pH 3.8的80 mmol/L Tris-H3PO4+15 mmol/L羟丙基-β-环糊精(HP--βCD)+5.0 g/L羧甲基-β-环糊精(CM--βCD)条件下获得成功分离。以(1R,2R)-2-氨基-1-苯基-1,3-丙二醇为内标,采用内标法定量,烯丙洛尔对映体在0.25~50 mg/L范围内具有良好线性关系,检出限(S/N=3)为0.25 mg/L,日内、日间RSD均不大于6%,平均回收率为97%~102%。该方法可用于鼠体内烯丙洛尔的药代动力学研究。     

手性流动相HPLC法拆分对羟基苯甘氨酸对映体的研究

将β-环糊精、羟丙基-β-环糊精作为手性流动相添加剂,系统地研究了D,L对羟基苯甘氨酸在RP-HPLC系统中的拆分。分别考察了手性流动相的种类,手性试剂β-环糊精的浓度,流动相的pH,修饰剂的种类及浓度,色谱柱温度等对拆分效果的影响,以-βCD为手性流动相添加剂,建立了-βCD手性流动相分离对羟基苯甘氨酸对映体的方法。结果表明:用ODS柱(250 mm×4.6 mmi.d.),以V(甲醇-β环糊精)∶V(pH 4.5磷酸盐缓冲液)=30∶70为流动相,流速0.2 mL/min,柱温25℃,检测波长为230 nm时对羟基苯甘氨酸对映体得到了良好的基线分离,分离度可达1.71。     

毛细管电泳拆分2-(9-蒽基)-2-羟基乙酸对映体

以羟丙基-β-环糊精为手性选择试剂,首次对外消旋的2-（9-蒽基）-2-羟基乙酸对映体的毛细管电泳分离进行了研究.比较了环糊精的种类、浓度、背景电解质的类型及pH对分离的影响.实验结果表明,采用15mmol/L羟丙基-β-环糊精为手性选择试剂,在20 mmol/L的三羟甲基氨基甲烷（Tris）-磷酸缓冲体系中（pH6.0）,2-（9-蒽基）-2-羟基乙酸对映体达到基线分离,分离度为1.58.     

气体分离膜研究进展

全面综述了近几年气体分离膜研究的最新进展,主要包括气体分离膜材料、制膜方法、表征方法三个方面。     

Lipophilic ternary complexes in liquid–liquid extraction of trivalent lanthanides

The formation of ternary complexes between lanthanide ions [Nd(III) or Eu(III)], octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO), and bis-(2-ethylhexyl)phosphoric acid (HDEHP) was probed by liquid–liquid extraction and spectroscopic techniques. Equilibrium modeling of data for the extraction of Nd(III) or Eu(III) from lactic acid media into n-dodecane solutions of CMPO and HDEHP indicates the predominant extracted species are of the type [Ln(AHA)₂(A)] and [Ln(CMPO)(AHA)₂(A)], where Ln?=?Nd or Eu and A represents the DEHP^? anion. FTIR (for both Eu and Nd) and visible spectrophotometry (in the case of Nd) indicate the formation of the [Ln(CMPO)(A)₃] complexes when CMPO is added to n-dodecane solutions of the LnA₃ compounds. Both techniques indicate a stronger propensity of CMPO to complex Nd(III) versus Eu(III).     

毛细管电泳法在手性分离中的应用及进展

近年来,毛细管电泳(CE) 手性分离方法的研究主要集中在各种手性添加剂与对映体药物的匹配及实验条件的最优化选择上.目前,较为成熟的CE分离模式有:区带电泳(CZE)、凝胶电泳(CGE)、等速电泳(CITP)、胶束电动色谱(MEKC)和非水电泳(NACE)等,并已成功地用于手性化合物对映体的分离.CE手性分离研究正朝着新型手性选择剂的研制和实现与其他各种定性分析仪器及其他色谱分离模式的联用方向发展.     

Comparison of Overpressured-Layer Chromatography and High-Performance/High-Pressure Layer Electrochromatography Using the New Prototype Equipment in Various Operational Modes

In our previous paper we have presented the new prototype equipment and introduced a new analytical technique—high-performance/high-pressure layer electrochromatography (HPLEC), a combination of overpressured-layer chromatography (OPLC) and pressurized planar electrochromatography (PPEC). In this paper, the work of the equipment in various operational modes is investigated. Some difficulties and challenges related to various aspects of separation are discussed. The OPLC and HPLEC techniques are compared in terms of selectivity and performance. The results show that our equipment can be successfully used for singe- and multichannel OPLC and HPLEC separations in various sample application and detection modes. It includes the high-throughput, multichannel, and fully automated online separation of multiple samples simultaneously. The equipment allows for the independent optimization of various operational parameters. HPLEC combines the advantages of column/capillary and planar separation techniques while overcoming their limitations. It also combines the advantages and overcomes the drawbacks of OPLC and PPEC. It provides hydrodynamic flow of the mobile phase, irrespective of the voltage used and/or the mobile phase composition. Thus, any optimization of the composition and the voltage can be used independently. Both can be used to obtain the required selectivity of separation. The voltage can be used to facilitate the mobile phase flow and accelerate the analysis.     

Applications of magnetic materials separation in biological nanomedicine

As a result of their advantages for superparamagnetic properties, good biocompatibility, and high binding capacity, functionalized magnetic materials became widely popular over the past couple of decades, being applied on large scale in various processes of sample preparation for biomedicine. In this work, we perform an in‐depth review on the current progress in the field of magnetic bead separation, discussing in detail the physical basis of this process, various synthesis methods and surface modification strategies. We place special focus of attention as well on the latest applications of magnetic polymer microspheres in cell separation, protein purification, immobilized enzyme, nucleic acid separation, and extraction of bioactive compounds with low molecular weight. Existing problems are highlighted and possible trends of magnetic separation techniques for biomedicine in the future are proposed.     

Fabrication of Matrimid/polyethersulfone dual-layer hollow fiber membranes for gas separation

We have developed almost defect-free Matrimid/polyethersulfone (PES) dual-layer hollow fibers with an ultra-thin outer layer of about 10 × 10⁻⁶ m (10 μm), studied the effects of spinneret and coagulant temperatures and dope flow rates on membrane morphology and separation performance, and highlighted the process similarities and differences between single-layer and dual-layer hollow fiber fabrications. The compositions of the outer and inner layer dopes were 26.2/58.8/15.0 (in wt.%) Matrimid/NMP/methanol and 36/51.2/12.8 (in wt.%) PES/NMP/ethanol, respectively. It is found that 25 °C for both spinneret and coagulant is a better condition, and the fibers thus spun exhibit an O₂/N₂ selectivity of 6.26 which is within the 87% of the intrinsic value and a calculated apparent dense-layer thickness of about 2886 × 10⁻¹⁰ m (2886 Å). These dual-layer membranes also have impressive CO₂/CH₄ selectivity of around 40 in mixed gas tests. The scanning electron microscopy (SEM) studies show that low coagulant temperatures produce dual-layer hollow fibers with an overall thicker thickness and tighter interfacial structure which may result in a higher substructure resistance and decrease the permeance and selectivity simultaneously. The elemental analysis of the interface skins confirms that a faster inter-layer diffusion occurs when the fibers are spun at higher spinneret temperatures. Experimental results also reveal that the separation performance of dual-layer hollow fiber membranes is extremely sensitive to the outer layer dope flow rate, and the inner layer dope flow rate also has some influence. SEM pictures indicate that the macrovoid formation in dual-layer asymmetric hollow fiber membranes is quite similar to that in single-layer ones. It appears that macrovoids observed in this study likely start from local stress imbalance and weak points.     

Sulfonated polysulfone-preparative routes and applications in membranes used for pressure driven techniques

There is much enthusiasm now-a-days for efforts to improve membrane performances. Membrane modification is one of the critical approaches needed for the development of membrane science and technology. The beauty of research in this orientation is that it is a dynamic process that moves forward slowly and recommendations are made based on the science available. In this regard sulfonation of polysulfones is an excellent move. The present review demonstrates different sulfonation strategies of polysulfones as well as promoting applications in pressure driven separation sciences (viz. salt, macromolecule, organic separation from water). It shows that marked path is promising one.     

混合萃取剂拆分氧氟沙星外消旋体

将混合萃取剂技术应用于氧氟沙星外消旋体的萃取分离,主要研究了氧氟沙星对映体在水和有机溶剂两相中的萃取分配行为。研究结果表明:在L-(-)-对甲基二苯甲酰酒石酸(L-DTTA)的浓度为0.18mol/L,L-(-)-二苯甲酰酒石酸(L-DBTA)的浓度为0.12mol/L,氧氟沙星浓度为0.2mg/mL,萃取温度为25℃,pH为7.00时,L型对映体和D型对映体的分配系数分别达到10.2和4.20,手性选择性达到2.43。     

Modelling of multifrequency IRMPD for laser isotope separation

The process of infrared multiple photon dissociation (IRMPD) of molecules is of great fundamental importance and has practical significance, such as isotope separation etc. Unfortunately, a clear insight into the process has been hindered by the bewildering array of important variables affecting MPD. The dissociation probability γ (φ) i.e. the yield has been found to be a sensitive function of laser fluence φ along with numerous other parameters like laser frequency, gas pressure etc. We have shown that in single frequency IRMPD, an accurate quantitative characterization of the dissociation probability can be adequately expressed by a ‘power law’ model with two fitting parameters namely critical fluence, φ_c and multiphoton order,m. This model was exploited in analysing our MPD results on various systems. However, the small isotope shift encountered in heavy elements and the sticking phenomenon observed in small light molecules restrict respectively the separation factor and the dissociation yield. These problems can effectively be tackled by irradiation with multifrequency laser beams which can be chosen appropriately on the basis of spectroscopic features. Based on our success in single frequency model, multifrequency IRMPD is modelled by a functional form containing the product of power law terms for individual fluences on irradiation frequencies. This model is successfully benchmarked with our experimental results on multifrequency LIS of tritium. Such knowledge can be utilized for appropriate separation process design, evaluation and optimization.     

Sheath-assisted versus sheathless dielectrophoretic particle separation

Lab-on-chip devices are widely being used for binary and ternary cell/particle separation applications. Among the lab-on-chip methods, dielectrophoresis (DEP) is a cost-effective and label-free method, with great capabilities for size-based separation of cells and particles, which is mostly performed in sheath-assisted forms. However, the elimination of the sheath flows offers advantages such as ease of operation and higher sample throughput. In this work, we present a comparison of sheath-assisted and sheathless DEP separation of three sizes of microparticles using tilted electrodes. The sheath-assisted design was capable of separating the 5, 10, and 15 μm particles with a separation efficiency as high as 98.0% for 15 μm particles. By adding a DEP focusing region, a sheathless DEP separator was proposed, which offered higher throughputs (up to 10 times) at the cost of lowering the separation efficiency (a reduction up to 10.3% for 15 μm) compared to the sheath-assisted design. To enhance the separation efficiency, a combination of the DEP focusing accompanied by weak sheath flows from both sides was proposed. This design achieved the highest sample separation yield in the outlets (as high as 98.7% for 15 μm) with a sample throughput of more than 4.2 μL/min. This study provides insights into the choice of an appropriate platform for any application in which the yield, purity, throughput, and portability must be considered.