色谱分离技术在淀粉糖工业中的应用

本文论述了色谱分离技术在淀粉糖工业中的应用情况。并对模拟移动床色谱技术在淀粉糖工业中的发展和应用特点,以及作者在这方面的工作进行了介绍。     

新型多组分连续制备色谱系统--阵列式柱色谱

本文介绍了一种新型多组分连续制备色谱系统———阵列式柱色谱。该系统是在综合了模拟移动床色谱和旋转环状色谱的工作原理的基础上开发出来的 ,主要由控制部分、流体输送部分、分离部分、检测部分和收集部分所组成。在分离部分中 ,本系统用色谱柱阵列代替了旋转环状色谱的环形填料层 ,即避免了溶质横向扩散和动密封问题 ,又可以根据实际生产需要增减色谱柱数目 ;在收集部分中 ,使用了专门为本系统设计的收集器实现了所有色谱柱流出液的集中收集 ;本系统采用将试验和生产一体化的设计 ,通过将单柱模式下的使用在线检测得出的优化分离条件应用到多柱模式中 ,实现了系统的柔性设计 ,降低了设备成本 ;用户可以通过使用装有系统控制软件的上位机与系统进行实时交互 ,大大提高了系统运行自动化程度 ,简化了操作。具有上述优点的本系统必将有着广泛的应用前景     

木糖醇母液色谱分离性能优化

在实验室模拟移动床(SMB)分离设备上成功地实现了木糖醇母液中木糖和木糖醇组份的分离提纯。并在平衡理论的框架下,采用基于真实移动床(TMB)的简化数学模型,以产品纯度和收率为系统分离性能的优化指标,研究SMB分离性能与操作条件之间的关系。通过对木糖醇母液SMB色谱分离过程操作条件的寻优仿真研究,确定稳态时柱内的木糖和木糖醇浓度分布状态;计算出不同操作条件时两组分产品液各自的纯度和收率变化规律图。在阀门切换时间为15min,进料木糖醇母液中木糖浓度35gL-1,木糖醇浓度114gL-1,进料和出料总量恒定为16mLmin-1,循环洗脱剂流量恒定为18mLmin-1的操作条件下,木糖醇母液进料流量在1~2.3mLmin-1范围内都可同时获得纯净木糖醇与木糖产品。在实验室SMB分离设备上进行了验证,得到的木糖和木糖醇产品液纯度和收率均达到了100%,所有实验结果与仿真曲线基本吻合。因此采用基于TMB的简化的平衡理论模型进行仿真和优化研究可分析和预测木糖母液SMB色谱分离系统操作条件对系统分离性能的影响,有效地指导了产品分离实验、工业化放大设计和生产优化操作。     

制备型高效液相色谱技术的研究进展

制备型高效液相色谱是一种快速,有效的分析分离工具.本文介绍了制备型高效液相色谱基础理论及基本装置,介绍了样品的预处理和应用实例,分析了目前制备型高效液相色谱技术存在的问题并对该技术未来的发展进行了展望.     

木糖与木糖醇色谱分离操作的质量优化

利用模拟移动床（SMB）连续色谱技术分离木糖醇母液中的木糖和木糖醇组分。在平衡理论的框架下，提出了使用基于相应的真实移动床（TMB）的简化数学模型，来研究各进料液和产品流出液的流量等操作参数的变化，对SMB分离性能（以纯度和收率作为性能指标）影响的方法。采用本方法进行了操作条件寻优仿真，并取得满意结果。在实验室SMB分离设备上，基于此最佳操作条件所得到的木糖和木糖醇产品液纯度和收率均达到100％。     

SMB两组份色谱分离过程建模与优化

基于TMB建模方法建立了二组份SMB色谱分离过程的理想数学模型。以提高产品纯度和收率为目标,依据Massimo三角形理论,研究了主要操作参数对SMB性能的影响,针对具体的分离对象进行了操作条件寻优仿真,并以此指导实际分离实验,得到满意的结果。     

茄尼醇的SFC制备色谱分离工艺

采用ZORBAX SB-C18(250 mm×9.4 mm I.D.,5 μm)色谱柱为固定相,SC-CO2/甲醇为流动相,考察了超临界流体色谱分离提纯烟草萃取物中茄尼醇的工艺条件、流动相流速和改性剂含量对分离度的影响,以及温度和压力对茄尼醇容量因子、茄尼醇与相邻色谱峰组分分离度和选择性因子的影响.通过采用选定SFC分离工艺条件,茄尼醇产品纯度达到94.9%.     

填料粒径对制备色谱生产的影响

随着绿色精细化工工业的发展,对制备色谱和模拟移动床色谱(SMBC)的需求越来越大。填料粒径的选择是制备色谱和模拟移动床色谱分离中的关键问题。填料粒径主要从柱效和压力两方面影响着制备色谱的应用。压力影响着运行成本,柱效影响着分离效果,但两者又互相制约。该文利用板高曲线和压力变化曲线斜率积对填料性能进行了比较。斜率积消除了填料粒径的影响,却又联系着其他与柱压力和柱效相关的因素。利用斜率积来评价填料性能对问题的分析更加深入。该文通过对不同粒径填料所填充柱的孔隙率、柱压和柱效的比较发现,随填料粒径减小,柱压力的上升幅度小于随填料粒径平方反比例增大的幅度,理论塔板高度减小。从银杏黄酮的模拟移动床色谱分离结果可以看出,使用粒径为20~25μm的填料,其产品纯度低于使用粒径为30~40μm的填料。     

吸附分离技术在PX工业生产中的运用

工业化的吸附分离技术生产PX,需要对从设备的接收到最终产品合格的整个过程严格的控制。本文以国内某石化厂PX装置的原始开工为例,详细介绍了：制造工艺的标准化,设备清洁化,装填密度可控化,仪表控制准确化,操作条件的不断优化。而所有的一切都要建立在准确计算和模拟的基础上。     

A new thermoset for separation of polystyrene and naphthalene in preparative chromatography

Many research groups in recent years have demonstrated the importance of obtaining new materials and reducing environmental impact. In this context, the chemical modification of cellulose and its derivatives has received much attention. This study synthesized cellulose acetate gel (CAMDIH) obtained through the modification of cellulose acetate (CA) with a degree of substitution of 2.5, by crosslinking reactions using 4,4′‐diphenylmethane diisocyanate in homogeneous medium. The formation of crosslinks were observed by the presence of Fourier transform infrared spectroscopy absorption bands at 3046 and 864 cm^?1, which correspond to the absorption of aromatic groups associated with the incorporation of 4,4′‐diphenylmethane diisocyanate in the CA structure. The potential applications of the gel as a stationary phase were tested using column chromatography in the fractionation and separation of standard solutions of polystyrene and naphthalene. The findings showed the effectiveness of the gel as a stationary state in the separation of mixture compounds. Furthermore, the study found that CAMDHI is an innovative material when considering its simple synthesis and the low costs involved in the process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46063.     

A new instrument for preparative gel permeation chromatography

A preparative liquid-phase chromatograph was built for the purpose of obtaining sufficiently large quantities of very narrow fractions of different polymeric species, such as polystyrene, PVC, polybutadiene, and polyethylene. This apparatus allows the fractionation of approximately 20 g of polymer per day; the fractions so obtained have polydispersities of about 1.1 over a very wide range of molecular weights. Polydispersities of less than 1.01 were obtained after recycling of the sample.     

生 化 分 离 技 术──制备型高效液相色谱

制备型高效液相色谱（ＨＰＬＣ）是在传统的分析型ＨＰＬＣ的基础上发展起来的一种高效分离纯化技术，主要用于制备高纯度生物活性物质。本文介绍了制备型ＨＰＬＣ的装置组成、制备规模及应用实例。     

Protein separation by high-performance membrane chromatography

High-performance membrane chromatography (HPMC) is a very effective Chromatographic method that combines the advantages of both membrane technology and column chromatography. In this work, proteins (myoglobin, conalbumin and soybean trypsin inhibitor) were separated by HPMC. The separation mechanism involved anionexchange, and the stationary phases were used anion CIM DEAE and QA disks (12x3 mm). Two types of mobile phase, buffer A (20 mM Tris-HCl, pH 7.4) and buffer B (buffer A+1 M NaCl) were used. As the amount of sodium chloride dissolved in buffer linearly increased, the retention time shortened and the resolution of the components was greatly improved. The optimum mobile phases and operating conditions were experimentally determined. From the experimental results, the proteins were separated within 2 min at a mobile phase flow rate of 4 ml/min.     

Computational algorithm to predict peak profiles in preparative high-performance chromatography

The computational algorithm and the Prep-LEAR program have been performed on the basis of the LEA model of chromatography. This program intends for calculation of peak profiles in non-linear high-performance chromatography and uses unsimplified adsorption isotherm equations. The computational algorithm and program have been tested by applying these to experimental data of thymine adsorption under conditions of reversed-phase high-performance liquid chromatography. The results of numerical calculations for different sample size introduced agree satisfactorily with experimental data and show the characteristic properties of high-performance chromatography. The usefulness of the Prep-LEAR program was confirmed by predicting peak profiles in preparative adsorption Chromatographic processes.     

A new preparative method for cyclohexenyl alkenyl ketones

New cyclohexenyl alkenyl ketones are prepared by the reaction of various methyl cyclohexenyl carboxylates and vinylmagnesium chloride; for example, 1-(4′-methyl-3′-cyclohexene-1′-yl)-1-oxo-4-pentene is obtained from methyl 4-methyl-3-cyclohexene-1-carboxylate and vinylmagnesium chloride.     

An electrostatic precipitator for preparative gas-liquid chromatography

The effect of the operating variables of electrostatic precipitators on the recovery and structure of methyl esters and related aerosol forming compounds collected in preparative gas-liquid chromatography was studied. Aerosol formation was prevented by AC or DC voltages of 5000 to 12000 volts. AC was more effective than DC but caused changes in structure which were detectable by both thin-layer and gas-liquid chromatographic methods of analysis. An apparatus of simple construction and operation was designed for the collection of methyl esters and its use demonstrated with several model compounds.     

Two-way chromatography: Flow reversal in non-linear preparative liquid chromatography

A liquid chromatographic process is described in which the mixture to be separates and the eluant are introduced alternately at either end of the colum The products are also withdrawn alternately at either end or in side-streams. Difrerent operating schemes are shown to be possible, according as the el is more, or less strongly retained by the adsorbent than the components to be separated.Experiments are presented on the ion-exchange chromatography of Na⁺ = K⁺ mixtures with H⁺ as eluant. A theoretical analysis is given using the non-linear multicomponent equilibrium theory and performance criteria are determined. Both experiments and theory lead to the following salient fea of the process, which permit to distinguish it from existing, analytical or preparative chromatographic processes: the process is preparative: it treats large injections of highly concentrated components; the process is separative: it does not merely remove solutes from a solvant, it separates solutes from each other; the process is a binary split: it gives two products; thus multicomponent mixtures require several steps if complete separation is desired; the process is non-linear, as a result of the high concentrations used; the tailing of the peaks induced by the non-linearity is counteracted by recompression due to flow-reversal; the process reduces dilution and saves eluant: one of the components may be collected highly concentrated, even pure, avoiding thus secondary separation; the process requires slightly more adsorbent capacity than conven chromatography, for the same production; the process works best when the eluant is more, or less strongly retained than the components to be separated, but not intermediately; the process uses intermediate storage of part of the effluents, and their “reflux” in subsequent steps.     

Comparison of process concepts for preparative chromatography

Preparative chromatography is a widely used unit operation in downstream processing. A major step for its implementation is the choice of the process concept. The most popular concept is batch chromatography (BC), which is easy to implement. But also the more complex simulated moving bed chromatography (SMBC) has reached a high significance over the last years. Between these two concepts, closed loop recycling (CLRC) and steady state recycling chromatography (SSRC) promise higher performance than BC and less complexity than SMBC. This paper will analyze the advantages and disadvantages of CLRC and SSRC compared to the both BC and SMBC.These four chromatographic concepts for different separation tasks are compared by dynamic process simulation. Therefore, six isotherms for two component systems are generated and three different feed compositions are regarded. For each case, all mentioned process concepts are optimized and compared with regard to performance. The results show that CLRC and SSRC can be a good choice, especially for difficult separations.