高效液相色谱法分离和鉴别棉花中13种糖

应用一根Ｓｈｉｍ－ｐａｃｋＣＬＣ－ＮＨ２柱（６０ｍｍ×１５０ｍｍ）和一根Ｌｉｃｈｒｏｓｏｒｂ－ＮＨ２柱（５ｍｍ×２５０ｍｍ）串联组合，用ＲＩＤ－６Ａ折光检测器检测，以ＣＨ３ＣＮ＋Ｈ２Ｏ（７５＋２５）作流动相，成功地分离了鼠李糖、木糖、树胶醛糖、果糖、葡萄糖、半乳糖、蔗糖、纤维二糖、海藻糖、乳糖、蜜二糖、松三糖、棉籽糖，建立一种快速简便的测糖方法。     

The Rapid Determination of Neutral Sugars in Biological Samples by High-Performance Liquid Chromatography

Abstract

A procedure for the analysis of neutral sugars in biological specimens is described. The method entails acid hydrolysis of the sample to liberate monosaccharides, which are subsequently derivatized with dansyl hydrazine. The sugar-dansyl hydrazones are separated and quantitated by hplc on a 5μ C18 RadialPak column with a gradient of acetonitrile in 10mM ammonium sulfate at pH 7. Fluorescent detection of the derivatized sugars permits 100-fold increased sensitivity compared to previously published glc methods.

This procedure was applied to the neutral sugar analysis of a glycoprotein of known composition (thyroglobulin) and to hard keratin fibers. The latter substance served as a model to critically evaluate the method on a highly resistant biological matrix containing low concentrations of neutral sugars.     

磁性高分子微球固定化中性蛋白酶的研究

以表面带羟基的磁性高分子微球为载体，对位苯醌活化后，通过共价结合修饰中性蛋白酶，得到比活性为１０００Ｕ／ｇ的磁性固定化酶。偶联蛋白量２０～３０ｍｇ／ｇ载体，固定化酶活性保持达４０％，自由酶和固定化酶相比，最适温度从５０℃变到５０～６０℃，最适ｐＨ从７．５变到６．５，Ｋｍ从０．０５４％变到０．０８８％酪蛋白溶液，ｐＨ稳定性、热稳定性、贮存稳定性都有较大提高．     

Gas Separation with Polymer Membranes

Gas-selective polymer membranes have long been used in industrial applications. Studies of polymers with well-defined flexible phenyl ether segments such as 1 should contribute to the understanding of the selection mechanism and thus ultimately lead to the synthesis of optimized membrane materials. Various different bridging groups X were used in the studies.     

Neutral Lipid Class Fractionation and Further Separation of Simple Neutral Glycolipids by OPTLC

Abstract

In lipid preparation from biological sources extraction and chromatographic methods are widely used. The use of the OPTLC method is introduced in the present paper. The method is suitable for the class separation of the neutral fraction of a total lipid extract with a single isocratic run. With a step or an exponential gradient the simple neutral glycolipids can be separated. Either elution can be performed on a 10 × 20 cm plate on 12 parallel samples. The chromatograms were evaluated by densitometric scanning after staining with orcinol-H²SO₄ reagent.     

以分子印迹聚合物为固定相分离和测定氟喹诺酮类药物

以氧氟沙星作为模板分子合成了分子印迹聚合物,并通过高效液相色谱法研究了印迹聚合物的识别特性。实验结果表明,印迹聚合物对模板分子具有很强的亲和力和特定的选择性。作为色谱固定相,氧氟沙星印迹聚合物和目标分子之间的相互作用除了印迹部分的离子和氢键作用外,也存在非印迹部分的疏水作用。同时研究了色谱条件对氟喹诺酮类药物分离的影响。     

Analysis of Neutral Sugars of Asparagus officinalis Linn. Polysaccharide by CZE with Amperometric Detection

Analysis of the neutral sugars of Asparagus officinalis Linn. polysaccharide by different methods has yielded inconsistent results. In the work discussed in this paper, capillary zone electrophoresis with amperometric detection (CZE–AD) was used for analysis of neutral sugars in A. officinalis Linn. polysaccharide. The configuration of the wall-jet and the diameter of the copper disk electrode were investigated to achieve optimized detection sensitivity. The separation electrolyte, separation voltage, and injection time were studied for their effects on CZE separation. Under the optimum CZE–AD conditions, seven monosaccharides were separated to baseline by using 120 mM NaOH as separation electrolyte. Linear response was excellent and repeatability was satisfactory. It was found that Asparagus polysaccharide was composed of fucose, galactose, glucose, rhamnose, arabinose, fructose, and xylose at a mole ratio of 0.2:16.2:5.0:1.0:15.5:0.6:18.8. Compared with other methods, analysis of the composition of Asparagus polysaccharide by CZE–AD had the merits of rapidness, accuracy, and lower sampling volume.

     

Separation of Hydrophobic Neutral Compounds by Microemulsion Electrokinetic Chromatography

Electrokineticchromatography(EKC)istheonlymodeofcapillaryelectrophoresisfOrtheseparationofelectricalneutralcompounds.Theseparationprincipleisbasedonthedifferentpartitionofsolutesbetweenthepseudostationaryphaseandthesurroundingaqueousphase.MicellarEKC(MEKC)provideshighspeedandhighefficiencyseparationforneutralcompoundswithsignificantsolubilityinaqueoussystem'.Theseparationofhydrophobiccompounds,however,givessomeproblems,becauseoftheirpoorsolubilityinaqueousphase.Inourpreviouswork"',somepol…     

Separation of Neutral Amino Acids with Ligand Exchange Resins

Four neutral amino acids (Gly, Ala,.Val and Leu) were separated with ligand exchange resins. The separation capacity of the ligand exchange resins is compared with that of common ion exchange resins. The effects of eluent, column temperature, and central metal ions of the support on the separation are studied. The relationship between matrix structure of resins and their separation capacity is analysed.     

聚合物共混物的相容性及相分离

综述了聚合物共混物相容性和相分离的研究现状。介绍了聚合物共混物的相容性理论,影响相容性的因素及改善和相容性的方法和表征相容性的手段。聚合物共混物的相分离机理制约着材料的性能,旋节分离和成核－增长相分离分别形成不同的形态结构。旋节分离和成核－增长相分离所对应的动力学过程是不同的,散射光强与相分离时间分别满足指数和幂指数关系。     

粘度对聚合物共混物相分离动力学的影响研究

模拟了粘度反差二元流体混合物的相分离,考察了粘度对相分离动力学的影响,发现相区域的增长主要由粘度较大的组分所控制,合理地解释了粘度效应所导致的一些实验现象.证明了即使组分间的粘度比很大,也没有出现反转相结构,说明在不施加剪切流场情况下,粘度反差不是形成反转相的原因.     

高分子相分离的分子动力学模拟

用粗粒化分子动力学(MD)模拟方法从分子层次研究两组分聚合物共混体系相分离过程中的动力学. 在相分离初期, 相区尺寸不随时间增加而变化; 在相分离中期, 相区尺寸与时间有很好的标度关系, 标度指数(α=1/3)符合Lifshiz-Slyozov提出的以扩散为主导的蒸发-凝聚机理的标度预测; 在相分离后期, 体系实现宏观相分离, 相区尺寸不再随时间改变而变化. 体积分数小的高分子链尺寸在相分离过程中先收缩再扩张, 在实现宏观相分离后, 高分子链尺寸又回到本体状态尺寸.     

Thin-Layer Chromatography of Neutral Sugars as Influenced by the Nature of the Cation of Impregnating Salt

Thin-layer chromatography of neutral sugars contained in water-soluble binders (gum and honey) was studied on silica gel plates impregnated with solutions of alkali, alkaline-earth, and transition metal sulfates at different pH and concentrations.     

电中性物质的毛细管胶束电动色谱

在自制的高效毛细管电泳装置上,使用内径为0.05毫米,长为450毫米的熔融石英毛细管,十二烷基硫酸钠胶束溶液,254nm检测波长,进行了电中性化合物的毛细管胶束电动色谱研究。并将乙醇-水混合溶剂引入体系,成功地进行了多环芳烃的分离。考察了电场强度,SDS浓度及乙醇含量对柱效的影响。     

Separation into Phases of Polymer Mixtures in Solution

When three different polymers are dissolved in a common solvent and the total polymer concentration is above a certain value, three liquid layers are obtained because of the limited compatibility of the polymer components with one another. Tests have been carried out at room temperature on solutions of polystyrene t polyvinyl acetate + polyvinyl chloride in tetrahydrofuran, and polystyrene t polyvinyl acetate t atactic polypropylene in benzene. Analysis of the individual layers yielded the following results: each polymer is always contained in each layer; the mixing ratios of the polymers in the three layers are generally different from one another and differ also from the mixing ratio of the starting mixture; each of the three layers is distinguished from the others by the fact that a specific polymer has been accumulated therein in preference to the other polymers. Concerning the quantitative distribution of the polymers among the layers, some laws could be found which can be explained qualitatively on the grounds of molecular-physical considerations. A solution of polystyrene t polyvinyl acetate t polyvinyl chloride t atactic polypropylene in tetrahydrofuran (equal amounts of polymers, total concentration about 10 g/100 ml) forms four layers, the composition of which was also determined by analysis.

When solutions of polymer mixtures are evaporated, separation into phases takes place because the polumers become incompatible with one another when the concentration exceeds a certain value. As a result, strongly inhomogeneous films are obtained after evaporation of the solvent. If the inhomogeneity of the films is not taken into consideration, misleading results may be obtained in the analysis of the films.

It is shown that in the system polystyrene + polyvinyl acetate, with tetrahydrofuran as solvent, surprising phenomena appear on the addition in stages of cyclohexane. The phenomena are due to the overlapping of separating and dissolving processes which have, in part, opposite actions.     

高分子混合物薄膜的相分离行为

从高分子混合物薄膜的相分离行为的机理，相分离后期粗化动力微区尺寸与时间的标度关系，影响高分子混合物薄膜表面形态形成的因素等几个方面对近年来高分子混合物薄膜相行为的研究进展进行总结，概述了今后可能的发展趋势。     

Separation of a CaCl2-HCl Model Mixture on Neutral Nanoporous Hypercrosslinked Polystyrene under Static and Dynamic Conditions

The distribution of CaCl₂ and HCl (separately and in a mixture) between the aqueous and nanoporous hypercrosslinked polystyrene sorbent phases was studied under static conditions. It was shown that virtually the whole pore volume of the sorbent was accessible to HCl, whereas CaCl₂ was largely excluded from small pores. It was found that the distribution isotherms of the electrolytes between the phases changed significantly in going from the pure electrolytes to their mixture. Under dynamic (chromatographic) conditions, the elution profiles of CaCl₂ and HCl (separately and in a mixture) were studied. It was shown that the components of the mixture competed for the pore space of the sorbent: small HCl molecules were displaced from large pores and the interstitial space into small pores inaccessible to CaCl₂. (This is why the retention of HCl in the chromatography column significantly increased as the concentration of the mixture grew; that is, both the efficiency and selectivity of separation increased as the column became loaded heavier.) It was found that the degree of hydration of ions decreased as the concentration of the solution increased.     

配位体交换树脂对中性氨基酸分离性能的研究

采用配位体交换树脂对中性氨基酸(Gly,Ala,Val和Leu)进行了分离,并与一般阳离子交换树脂的分离性能进行了比较,对淋洗剂、柱温等分离条件进行了实验;研究了树脂载体结构、功能基及配位中心离子对分离性能的影响。