柱吸附容量对蔗糖还原糖色谱分离过程产率和回收率的影响

本文采用了能反映流体轴向扩散的大型液相色谱分离过程数学模型,应用计算机模拟分析蔗糖和还原糖的色谱分离过程,从吸附剂吸附容量和柱装填密度两个方面;考察柱吸附容量对大型色谱分离的产率和回收率的影响。研究结果表明：在色谱柱中流体线速度恒定的条件下对多组分分离,回收率是随吸附剂吸附容量以及床层装填密度的增大而增大的;产率先随吸附剂吸附容量的增大而增大,而在出现峰值后下降;随着床层装填密度的增大,产率增加,但与此同时轴向扩散系数也增大,从而降低分离效率,导致在较高装填密度的范围内产率增力。的幅度减少。在相同的吸附剂用量下,采用短柱高装填密度的色谱柱将比长柱低装填密度色谱柱能获得更高的回收率和产率。     

循环制备液相色谱分离芳香新塔花中的化学成分

建立了交替循环和直接循环液相色谱相结合的方法用于制备芳香新塔花中的化学成分.芳香新塔花样品经溶剂提取、柱色谱和中压制备色谱初步分离后得到芳香新塔花的不同馏分.以甲醇-水为流动相,利用双柱交替循环法对组分进行分离,同时,流动相经恒流泵循环输入色谱柱.以馏分Ⅰ和馏分Ⅱ为例,在混合循环模式下分离得到5个化合物.通过核磁共振对其进行鉴定,确定分别为乔松素-7-O-芸香糖苷、白杨素-7-O-芸香糖苷、金合欢素-7-O-芸香糖苷、云杉素和原儿茶酸.实验结果表明,该制备方法分离效率高,节省流动相,是分离天然产物的有效手段.     

大型工业液相色谱分离山梨醇和甘露醇过程优化研究

本文采用非线性非平衡含轴向扩散色谱数学模型模拟山梨醇-甘露醇同分异构体系大型工业液相色谱分离过程。首先，通过对分离过程进行参数灵敏度分析，确定了被优参数为进料浓度和色谱柱柱长；然后，以山梨醇的产率为目标函数，限定山梨醇的产品纯度和最小回收率，利用改进的单纯形法对分离过程进行两参数优化，分析了不同进料量和流体线速对最优条件的影响。结果表明：进料量和流体线速对回收率和最大产率的影响程度与参数灵敏度分析结果基本一致，从而证明了利用参数灵敏度分析方法选择色谱分离过程被优参数的可行性。本文还对改进的单纯形法寻优过程进行了探讨，构造了单纯形法优化大型液相色谱的基本方法和框图。     

加压毛细管电色谱及其新型固定相的制备和应用

毛细管电色谱(Capillary electrochromatography,CEC)是一种结合了高效毛细管电泳(HPCE)的高柱效和微柱液相色谱(μHPLC)的高选择性的一种新型分离方法.由于在CEC分离中采用电渗流(EOF)作为推动力推动流动相,因而使得CEC具有比HPLC更高的分离效率和峰容量.因为在CEC分离过程中不存在反压,在HPLC中很难使用的微米和亚微米颗粒已经开始在CEC分离柱中获得应用,这也使得CEC获得了比HPLC高得多的分离效率.虽然根据理论预测,使用亚微米颗粒将获得更高的分离效率,然而,到目前为止,只有很少人尝试过使用亚微米颗粒作为填充固定相.     

二维液相色谱-质谱联用分离中药复方葛根芩连汤中的有效成分

建立了二维液相色谱-质谱联用方法分离中药复方葛根芩连汤的成分。以CN柱作第一维色谱柱,水和甲醇梯度洗脱分离;以ODS柱作第二维色谱柱,20 mmol/L乙酸铵缓冲液和乙腈梯度洗脱分离;质谱检测采用电喷雾电离/大气压化学电离（ESI/APCI）复合离子源,正负离子扫描。实验结果表明搭建的二维液相色谱的峰容量显著高于一维色谱,分离效率得到了明显的提高。以第一维色谱的第3个流分为例,对其二维分离进行仔细分析,发现质谱比紫外光谱检测到的组分多,质谱中采用负离子模式比正离子模式检测到的组分多。表明搭建的二维液相色谱-质谱分离平台分离效果好,提高了液相色谱的峰容量和分离效率。该方法操作简便,可作为中药等复杂体系分离分析的有效手段。     

木屑在鼓泡流化床和循环流化床中气化特性的对比研究

对木屑在内径分别为0.3m×0.3m的鼓泡流化床气化炉（BFBG）和内径0.4m的循环流化床气化炉(CFBG)中的气化特征进行了对比，重点考察了当量比对生物质气化特性的影响。实验结果表明,在相同当量比下，由于CFBG操作气速明显高于BFBG，床内强烈的气固传热传质，使得CFBG可以获得较高的热解速率,同时可以使 CFBG在较高温度下运行。较高的运行温度不仅有利于二次裂解气化反应，使可燃气体质量明显好于BFBG，同时也减少了燃气中焦油的量。在较低气化当量比下(ER≤0.28)，CFBG比BFBG可以获得更高的气体产率、碳转化率和气体效率;在较高当量比下,(ER＞0.28)，CFBG和BFBG的气体产率、碳转化率和气体效率则相差不大。     

C18柱串联冠醚手性柱高效分离3种芳香族氨基酸对映体

将C18柱与手性冠醚柱串联,建立了一种反相高效液相色谱法用于3种芳香族氨基酸对映体同时拆分的方法.考察了反相色谱流动相的组成、pH值、柱温、流速对对映体拆分的影响.实验结果表明,当流动相为HClO4-乙睛溶液(86:14,V/V,pH 2.0)、柱温20℃、流速0.4 mL/min时,3种氨基酸对映体可获得基线分离.进一步对比了C18柱、冠醚手性柱和串联顺序不同的4种分离模式,结果表明,C18柱不能拆分氨基酸对映体,仅能分离不同种类氨基酸;冠醚手性柱可分离氨基酸映体,但不同种类氨基酸色谱峰出现重叠;串联模式能实现3种氨基酸对映体的基线分离,实现双柱优势互补,而串联顺序对分离影响不大,仅影响色谱峰的峰形.     

双柱切换色谱制备系统设计和实现

在模拟移动床色谱和循环色谱分离手性样品原理的基础上,设计了双柱切换系统及控制软件。该系统具有固定相的利用率高和溶剂的消耗量小的特点。为了验证分离原理的可行性。用该系统对华法令进行了连续制备。     

全二维液相色谱(IEC/RP)的构建与评价

以IEC/RP模式构建了二维液相色谱系统,采用平行交替柱捕集分析的2位十通切换阀作接口,第一维洗脱产物按10:1的分流比分流后,得到IEC和RP切换谱图.以5个标准蛋白混合物的分离评价该系统,在单独一维模式中不能分离的样品在全二维液相色谱中得到了很好的分离.     

聚合物假冠醚研究（Ⅰ）单体乙二醇二苯醚的合成与表征

本文以乙二醇为底物,通过中间体乙二醇二苯磺酸酯,合成出了乙二醇二苯醚。对两合成产物进行了红外光谱、薄层色谱。溶解性能及结晶分析,实验结果表明,在乙二醇二苯磺酸酯的合成中,因为使用苯磺酰氯代替了传统的对甲苯磺酰氯磺酰化试剂,并用氯仿做稀释剂以控制催化剂吡啶的恰当使用量,使合成不但经济而且获得82．5％,的较高收率,在乙二醇二苯醚的合成中,采用回流,蒸馏交替使用的实验方法,同时用馏出物沸点数值监控和及时排除体系的水份,使产率达到78．0％。     

A FAD-SMT Model of Large Scale Liquid Adsorption Chromatography

The paper proposes a FAD-SMT model of large-scale liquid chromatography by which a continuous equation of chromatographic separation is decomposed into a convection dispersion partial differential equation and a set of ordinary differential equations. The numerical method for the FAD-SMT model is established. The stability and the convergence condition of numerical solution, and the choice of time and space interval are discussed. The FAD-SMT model is used to simulate liquid adsorption chromatography and cycling adsorption chromatography. Results show that the elution curves calculated by FAD-SMT model are good agreement with the experimental elution curves of the separation of glucose and fructose, the separation of sucrose and reducing sugar and the separation of mannitol and sorbitol. The result of parameter sensitivity analysis shows that the chromatographic elution curves are more sensitive to the changes of the parameter ai in Langmuir isotherms than to the changes of other parameters in the studied system.     

Capillary electrochromatography of peptides on a column packed with tentacular weak cation-exchanger particles

Silica-based, tentacular weak cation-exchanger particles were prepared for use as the stationary phase in the separation of positively charged sample components by capillary electrochromatography (CEC). Silica beads were first silanized with 3-(trimethoxysilyl) propyl methacrylate that served as a heterobifunctional linker, which reacted with 2-acrylarmidoglycolic acid in a second step by radical polymerization in aqueous solution. Baseline separation of basic peptides with good column efficiency was obtained on packed capillary columns by isocratic elution CEC with NaCl as the mobile phase modulator. The retention mechanism in the electrochromatographic process was studied by examining the effect of salt concentration on the migration behavior of the peptides. The chromatographic retention factor k'(lc) for charged sample components in the electrochromatographic process was estimated on the assumption that the overall migration rate of a charged migrant can be taken as the sum of the rate of chromatographic elution and the rate of electrophoretic migration. The estimated k(lc) values from experimental results were plotted against the molal salt concentration on a double logarithmic scale. The linear correlation is in good agreement with the prediction by the theory on the basis of traditional ion-exchange chromatography. The comparison of CEC results, obtained with open tubular and packed capillary columns having the same retentive functions as the stationary phase, supports the notion that variation of the phase ratio in the column offers an additional means to modulate the electrochromatographic migration behavior.     

SYSTEM IDENTIFICATION METHOD OF LINEAR AND NON-LINEAR LIQUID PREPARATIVECHROMATOGRAPHIC SEPARATION

1.INTRODUCTIONThechromatographicproblemistorelatetheconcentrationprofileofthebandattheoutletofthecolumntotheequilibriumisothelm,themasstransferkineticsandtheprofileoftheinjectionbandandperformtheoptimumdesignofseparationprocess['J.Togettheobjective,Itisnecessarytoidentifythesystemof.ProjectsupPOrtedbyTheNationalNaturalScienceFoundationofChinatheliquidadsorptionchromatographylinearornon-linear,andthendeterminethethermodynamicanddynamicsparametersofthesystemaccuratelysothatthecomputersim…     

特征线法在求解非线性液相吸附色谱模型中的应用

本文应用特征线法求解非线性液相吸附色谱分离过程模型，论述了特征线法的原理和步骤，讨论了时间步长和空间步长对模型数值解的影响，并用色谱分离甘露醇和山梨醇以及分离蔗糖和还原糖的实验进行验证，用特征线法计算的理论流出曲线与实验流出线吻合较好。本文还分折了模型中各个参数的灵敏度，结果表明：吸附等温方程Q＝Ci*／（ai＋biCi*）中参数ai比参数bi以及总传质系数ki有更高的灵敏度。     

Theoretical background of short chromatographic layers. Optimization of gradient elution in short columns

Although linear salt gradient elution ion-exchange chromatography (IEC) of proteins is commonly carried out with relatively short columns, it is still not clear how the column length affects the separation performance and the economics of the process. The separation performance can be adjusted by changing a combination of the column length, the gradient slope and the flow velocity. The same resolution can be obtained with a given column length with different combinations of the gradient slope and the flow velocity. This results in different separation time and elution volume at the same resolution. Based on our previous model, a method for determining the separation time and the elution volume relationship for the same resolution (iso-resolution curve) was developed. The effect of the column length and the mass transfer rate on the iso-resolution curve was examined. A long column and/or high mass transfer rate results in lesser elution volume. The resolution data with porous bead packed columns and monolithic columns were in good agreement with the calculated iso-resolution curves. Although the elution volume can be reduced with increasing column length, the pressure drop limits govern the optimum conditions.     

吸附剂性能和操作参数对液相色谱流出峰不对称性的影响

色谱流出峰的拖尾现象普遍存在于制备和大型色谱分离过程中,它直接影响分离的产率和回收率．本文提出采用色谱流出峰形的不对称偏差度来表征色谱流出峰的拖尾程度;并基于液相制备色谱分离过程FAD－SMT模型及吸附速率理论,通过计算机模拟,定量分析了吸附剂性能和操作参数对色谱流出峰形不对称性的影响。结果表明：不仅是吸附剂的热力学和动力学性能（包括吸附相平衡关系、液固两相间的传质阻力）;而且柱的设计和吸附剂的装填状况（包括轴向扩散系数）,以及色谱分离的操作条件（进料时间、浓度和流速等）都直接影响色谱流出峰形的不对称性。随着吸附相平衡等温线的非线性程度增大,或者总传质系数的减小,色谱流出峰形的不对称偏差度明显增大;吸附剂吸附容量的减小也将引起色谱流出峰形的不对称偏差度的增加;色谱流出峰形的不对称偏差度与进科体积、浓度和流体线速,以及轴向扩散系数的增大成正比。     

On the optimization of the solid core radius of superficially porous particles for finite adsorption rate

Packed chromatographic columns with the superficially porous particles (porous shell particles) guarantee higher efficiency. The theoretical equation of the Height Equivalent to a Theoretical Plate (HETP), for columns packed with spherical superficially porous particles, was used for the analysis of the column efficiency for finite rate of adsorption-desorption process. The HETP equation was calculated by the application of the moment analysis to elution peaks evaluated with the General Rate (GR) model. The optimal solid core radius for maximum column efficiency was estimated for a wide spectrum of internal and external mass transfer resistances, adsorption kinetic rate and axial dispersion. The separation power of the shell adsorbent for two component mixture, in analytical and preparative chromatography, was discussed. The conditions of the equivalence between the solutions of the General Rate model with slow adsorption kinetic and the Lumped Kinetic Model (LKM) or the Equilibrium Dispersive (ED) model were formulated.     

DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS OF LARGE SCALE CHROMATOGRAPHIC SEPARATION OF SUGAR AND REDUCING SUGAR

The parameter identification model of large scale chromatography separation process is proposed.The phase equilibrium constants and lumped mass transfer coefficients of sugar and reducing sugar adsorption on D1,D2 and D3 resins as well as the axial dispersion coefficients of the fluid through packed columns are determined by means of the pulse-response experiment technique with an inert substance as a tracer and the chromatography measuring technique.The elution curve calculated from these parameters is good agreement with the experimental elution curve.The sensitivity analysis of these parameters is carried out ,and the result shows that the elution curves of chromatography separation are more sensitive to the variations of the phase equilibrium relationship than to the variation of the axial dispersion as well as the lumped mass transfer coefficients.     

DETERMINATION OF THERMODYNAMIC AND KINETIC PARAMETERS OF LARGE SCALE CHROMATOGRAPHIC SEPARATION OF SUGAR AND REDUCING SUGAR

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Stationary phase modulation in liquid chromatography through the serial coupling of columns: A review

Liquid chromatography with single columns often does not succeed in the analysis of complex samples, in terms of resolution and analysis time. A relatively simple solution to enhance chromatographic resolution is the modulation of the stationary phase through the serial coupling of columns. This can be implemented with any type of column using compatible elution conditions and conventional instruments. This review describes the key features of column coupling and published procedures, where two or more columns were coupled in series to solve separation problems. In all reports, the authors could not resolve their samples with single columns, whereas significant enhancement in chromatographic performance was obtained when the columns were combined. Particularly interesting is the reduction in the analysis time in the isocratic mode, which alleviates the “general elution problem” of liquid chromatography, and may represent a stimulus for the proposal of new procedures, especially in combination with mass spectrometric, electrochemical and refractometric detection. Developments proposed to make the serial coupling of columns useful in routine and research laboratories are outlined, including optimisation strategies that facilitate the selection of the appropriate column combination and elution conditions (solvent content, flow rate or temperature) in both isocratic and gradient modes. The availability of zero dead volume couplers, able to connect standard columns, and the commercialisation of short columns with multiple lengths, have expanded the possibilities of success.