高比表面季铵基树脂的结构调控及在三七叶总皂甙纯化中的应用研究

利用Davankov后交联反应,合成了一类兼具高比表面积和高功能基含量的季铵基(—N+(CH)3)吸附树脂,考察了树脂比表面积和功能基含量的调控规律,并将其用于三七叶总皂甙的进一步纯化.结果表明,当树脂比表面积为692m2/g,交换量为2.1mmol/g时,树脂具有最佳的纯化效果,只通过吸附—解吸一步工艺,产品纯度即可从32.0%提高到90%以上,皂甙的回收率高于95%.最后,初步探讨了树脂对皂甙和色素的吸附机理,认为树脂对皂甙的吸附是单纯的疏水性作用力,而对色素的吸附应为疏水-离子交换双重作用的协同效应.     

泽泻醇类化合物与血清白蛋白相互作用的分子机理研究

中药泽泻具有抗肿瘤作用,可能与血清中蛋白成分的改变有关.利用荧光光谱、圆二色谱结合分子模拟技术研究了模拟生理条件下泽泻有效成分泽泻醇类化合物与人血清白蛋白的相互作用.实验结果表明,23-乙酰泽泻醇B与蛋白的结合作用远强于24-乙酰泽泻醇A.分子模拟结果与实验一致,并且表明,结合强弱的差异与小分子的侧链结构有关.该结果可...     

氢键吸附树脂的合成及高纯度沙棘叶黄酮的制备

针对黄酮分子的酚羟基结构特点,有目的地选择了4种结构不同的商品化树脂,考察了它们对沙棘叶中黄酮类有效成分的吸附能力和吸附选择性.在此基础上优化了树脂结构设计方案,合成了具有氨基功能基、可形成氢键作用、疏水性可调变的大孔吸附树脂.以沙棘叶粗提物为原料,考察了树脂骨架疏水性、功能基间隔臂长短等对树脂纯化效果的影响规律.研究结果表明,当吸附发生在水体系中,一定强度的疏水性作用是树脂与吸附质之间形成氢键的必要条件,对于尺寸较大的黄酮分子,氢键功能基的间隔臂长短也显著影响了树脂对它的吸附能力.最后,我们选择了疏水性和氢键功能基间隔臂长短适宜的XM20-2树脂,对吸附和洗脱条件进行了优化,将其用于沙棘叶粗提物中黄酮类有效成分的进一步纯化,可将黄酮纯度从粗提物中的10.4%提高到50%以上,且树脂具有很好的重复使用性.     

液相色谱指纹图谱在泽泻动态研究中的应用

应用指纹图谱技术,结合指标成分测定,采用高效液相色谱法,乙腈-水梯度洗脱,流速1．0mL／min,柱温20℃,色谱图光谱采集范围200～800nm,探讨了泽泻动态积累的规律。以泽泻标准对照药材为参照,用指标成分24-乙酰泽泻醇A和23-乙酰泽泻醇B进行了定位和测定,找出了21个共有峰,其中12号和20号峰分别为24-乙酰泽泻醇A和23-乙酰泽泻醇B。结果表明：泽泻样品指纹图谱及指标成分测定可为泽泻的最佳采收期提供科学依据。     

泽泻三萜类成分的提取工艺优化及活性评价

建立泽泻中三萜类成分的最佳提取工艺,并考察其对老年性耳聋小鼠血清生理学指标的影响.通过正交试验优化泽泻三萜类成分的提取工艺,并用紫外分光光度法(UV)测定含量.采用D-半乳糖建立小鼠老年性耳聋模型,灌胃给予泽泻三萜类成分提取物后,测定小鼠血清丙二醛(MDA)含量和超氧化物歧化酶(SOD)活力.结果表明:泽泻三萜类成分的...     

原位电离实时直接分析串联质谱法鉴别中药泽泻化学成分

建立原位电离实时直接分析串联质谱法快速鉴别中药泽泻中的化学成分。使用质谱正离子全扫描采集泽泻的DART MS特征图谱,通过与已报道的泽泻化学成分的相对分子质量比对确证泽泻醇类成分。在正离子模式下,泽泻固体样品直接显示特征指纹离子,液体样品图谱中出现文献报道的23-乙酰泽泻醇B(m/z 515)、泽泻醇C(m/z 487)、泽泻醇A(m/z 491)、泽泻醇B(m/z 473)、11-去氧泽泻醇A(m/z 475)等成分的[M+H]~+离子。该法操作简便、专属性强。能快速、直接、原位、高通量定性、定量分析,为药材、饮片的快速鉴别提供了新方法,具有良好的应用前景。     

二乙烯苯-异氰酸三烯丙基酯-丙烯腈共聚物大孔树脂对原花青素的吸附

根据原花青素含有疏水性的苯环和酚羟基的特点,设计合成了含有苯环和酰胺基的大孔二乙烯苯-异氰酸三烯丙基酯-丙烯腈(DTA)共聚物吸附树脂,DTA树脂通过疏水作用和氢键吸附原花青素.比较了DTA吸附树脂和3种商品化吸附树脂ADS-5(非极性)、ADS-8(弱极性)和ADS-17(中极性)对原花青素的吸附性能.结果表明,DTA、ADS-8、ADS-17对原花青素的吸附既包含疏水作用又有氢键参与.在合适的单体和致孔剂配比情况下合成的DTA吸附树脂对原花青素有很好的吸附性能.     

后交联St-DVB吸附树脂对水中低浓度高水溶性有机物的吸附、解吸与回收研究

分别测定后交联苯乙烯-二乙烯基苯(St-DVB)大孔吸附树脂XDA对于浓度在500～1000mg/L且能与水完全互溶的几种低分子含氧有机物的静态和动态吸附性能,采用蒸汽解吸与冰水冷凝精馏一体化技术,探索树脂吸附能力与有机物分子疏水值之间的相关性,以及采用该工艺从含有高价值高水溶性有机污染物废水中分离回收污染物资源的可能性。结果显示,该树脂对浓度500～5000mg/L的8种低级醇、醛和丙酮等均具有一定的吸附能力,其吸附能力与吸附质分子的疏水值呈正相关性,对疏水值较高的丙酮和四氢呋喃的吸附能力最强;树脂吸附饱和后采用蒸汽解吸法可达98%的解吸率,解吸液浓度较吸附原液溶质浓度提高了30～40倍,采用冰水冷凝法精馏工艺前段浓解吸液,回收率达70%～80%。     

大孔吸附树脂法柚皮果胶脱色工艺研究

比较了AB-8、S-8、X-5、聚酰胺、NKA-Ⅱ、NPD-600等6种大孔吸附树脂对柚皮果胶的脱色效果.在静态吸附试验研究的基础上,筛选出效果较好的树脂进行动态试验研究.实验表明:AB-8型大孔吸附树脂对柚皮果胶提取液具有较好的吸附脱色效果和较低的果胶损失率,该树脂对柚皮果胶脱色的适宜工艺参数为:室温(约20℃),流速3BV/h,溶液处理量为5BV,上柱液pH值为4～6.此工艺对果胶提取液中色素的吸附率约80%.树脂吸附后可用70%乙醇进行洗涤再生,果胶提取液脱色后经喷雾干燥所得的果胶成品质量符合QB2484-2000标准.     

树脂对化工废水中有毒有机化合物的吸附作用机理与技术研究

超高交联吸附树脂对多种芳香有机化合物较高的吸附容量主要源于其密集的微孔和双峰孔分布.对大孔吸附树脂及超高交联吸附树脂采用不同极性功能基团进行化学修饰可以制得系列离子交换与吸附双重功能吸附树脂,该类树脂对亲水性有机污染物同时具有疏水、静电、络合等多重作用.丙烯酸酯类吸附树脂在吸附芳香磺酸盐时,树脂的骨架和功能基团对吸附过程都有重要的贡献.     

Selective removal of caffeine from tea extracts using macroporous crosslinked polyvinyl alcohol adsorbents

The hydrolysis reaction of ester groups in vinyl acetate (VAc) was used to introduce hydroxyl groups into the matrix of a macroporous adsorbent, which was itself prepared by free radical suspension copolymerization of triallyl isocyanurate (TAIC) and VAc. Therefore, the copolymerization incompatibility between the hydrophilic and the hydrophobic monomer was overcome successfully and the hydrophobic matrix of the polymeric adsorbent containing a polyvinyl alcohol (PVA) segment was obtained. Introduction of the PVA segment decreased the hydrophobic adsorption affinity of the adsorbent while producing the hydrogen-bonding interaction. When isolating the two active components, polyphenols (TPh) and caffeine (CAF), from green tea extracts, this polymeric adsorbent, namely poly(TAIC-co-VA), exhibited good adsorption selectivity towards TPh over CAF. The adsorption mechanism leading to this selectivity involved a hydrophobic interaction mechanism for CAF and multiple weak hydrophobic and hydrogen-bonding interactions for TPh. The adsorption thermodynamics for TPh on poly(TAIC-co-VA) were studied. The effects of adsorbent structure and gradient desorption conditions on isolation were investigated. The result showed that adsorbent, with 20% TAIC content, was able to efficiently remove CAF from different tea extracts with different ratios of TPh and CAF. Finally, almost no CAF was detected in the TPh fraction and the recovery of TPh was greater than 95%.     

Amino acid adsorption on mesoporous materials: influence of types of amino acids, modification of mesoporous materials, and solution conditions

In order to disclose the dominant interfacial interaction between amino acids and ordered mesoporous materials, the adsorption behaviors of five amino acids on four mesoporous materials were investigated in aqueous solutions with adjustable amino acid concentration, ion strength, and pH. The selected amino acids were acidic amino acid glutamic acid (Glu), basic amino acid arginine (Arg), and neutral amino acids phenylalanine (Phe), leucine (Leu), and alanine (Ala), and the selected mesoporous materials were SBA-15, Al-SBA-15, CH3(10%)-SBA-15, and CH3(20%)-SBA-15. The adsorption capacities of Glu and Arg were strongly dependent on pH and surface charge of the mesoporous adsorbent. The adsorption of Phe showed pH insensitivity but depended on the surface organic functionalization of mesoporous adsorbent. On the basis of the theoretical analysis about the interaction between amino acid and adsorbent, such a remarkable difference was attributed to the different nature of the interaction between amino acid and adsorbent. Arg could be readily adsorbed on the surface of SBA-15, especially Al-SBA-15, under appropriate pH in which the electrostatic interaction was predominant. The driving force of Phe adsorption on mesoporous adsorbent mainly came from the hydrophobic interaction. Therefore, the adsorption capability of Arg decreased with increasing ion strength of solution, while the adsorption capability of Phe increased with the increasing degree of CH3 functionalization on SBA-15. For neutral amino acid Phe, Ala, and Leu, the adsorption capability increased with the increase of the length of their side chains, which was another evidence of hydrophobic effect. Thus, all the adsorption of amino acids on mesoporous silica materials can be decided by the combined influence of two fundamental interactions: electrostatic attraction and hydrophobic effect.     

Calorimetric investigation of the adsorption of nitrogen bases and nucleosides on a hydrophobic interaction sorbent

Heats of adsorption for nitrogen bases and nucleosides on Sepharose CL-6B, a hydrophobic interaction adsorbent, were collected through flow microcalorimetry in order to ascertain the thermodynamic driving force for adsorption in each case. It was determined that enthalpy changes associated with base stacking self-interactions can contribute significantly to the observed heats of adsorption. Accordingly, the observed heats were the net effect of the adsorbate/adsorbent interactions and the adsorbate stacking self-interactions. Since base stacking proceeds beyond the dimer stage, multi-layer adsorption of these compounds is possible, even at low solution concentrations.     

Factors affecting drug adsorption on beta zeolites

The adsorption behaviour of three commonly used drugs, namely ketoprofen, hydrochlorothiazide and atenolol, from diluted aqueous solutions on beta zeolites with different SiO₂/Al₂O₃ ratio (i.e. 25, 38 and 360) was investigated by changing the ionic strength and the pH, before and after thermal treatment of the adsorbents. The selective adsorption of drugs was confirmed by thermogravimetry and X‐ray diffraction. The adsorption capacity of beta zeolites was strongly dependent on both the solution pH and the alumina content of the adsorbent. Such a remarkable difference was interpreted as a function of the interactions between drug molecules and zeolite surface functional groups. Atenolol was readily adsorbed on the less hydrophobic zeolite, under pH conditions in which electrostatic interactions were predominant. On the other hand, ketoprofen adsorption was mainly driven by hydrophobic interactions. For undissociated molecules the adsorption capability increased with the increase of hydrophobicity.     

稻壳吸附剂提高啤酒稳定性的研究

利用稻壳良好的吸附特性,制备成吸附剂用于提高啤酒的稳定性。稻壳粉碎与稀硫酸混合,240℃密封干馏,再以高温灼烧活化,得到对单宁有较强吸附能力的稻壳吸附剂。以此吸附剂去除啤酒中的部分单宁,以提高酒体的胶体稳定性,试验表明,每100ml啤酒以0．4g吸附剂在15℃下搅拌吸30min,可使酒中单宁量下降16．7％,从而减缓了引起啤酒混浊的缔合反应,使酒体稳定性明显提高。与聚乙烯聚吡咯烷酮比较,具有吸附速度快、吸附单宁更强及成本低廉的优点。     

A Multipurpose Lignin‐based Adsorbent for Metallic Ions,Nanoparticles and Various Organophosphate Pesticides in Hexane

A lignin‐based adsorbent for metallic ions, nanoparticles and various agricultural organophosphate pesticides in hexane is immobilized on silica gel without further fractional purification. For most organophosphate analytes examined in this study under the same conditions, the percentage of adsorption achieved was well above 90% in 15 min, was found to be highly related to the dipole‐dipole attractions that occurred among the oxygen‐containing functional groups attached to analyte and lignin molecules and was greatly enhanced in hexane. The adsorption is believed to be reversible and surface oriented; furthermore, the interaction leading to the adsorption is not as significantly subject to the steric hindrance effect caused by the bulky group or elements surrounding the phosphorus element. Other types of interactions enhanced in hexane, such as the π‐π interaction, and hydrogen bonding in some cases, were also observed and contributed less to the percentage of adsorption. However, the adsorption of ions and nanoparticles under aqueous conditions is thought to be mainly a result of the complexation of the oxygen‐bearing hydrophobic cleft of the lignin molecule. In all cases, the nature of the analyte, the amount of adsorbent and the acidic or basic origin of the additive in matrix also affect the percentage of adsorption.     

MODIFICATION OF X-5 RESIN AND ADSORPTION PROPERTY OF THE MODIFIED RESINS

1. INTRODUCTION Adsorption capacity and selectivity are improved when some ion exchange groups or hydrogen bonding acceptor or/and donors are introduced into common polymeric adsorbents [1~5]. R. F. Shi et al have synthesized a series of bifunctional ads…     

An Analysis of the Interactions of BSA with an Anion-Exchange Surface Under Linear and Non-Linear Conditions

The interactions of BSA with an anion-exchange adsorbent have been studied to aid in the understanding of protein adsorption in ion-exchange chromatography. Linear chromatography, flow microcalorimetry and isotherm measurements were used to analyze adsorption energetics in the linear and overloaded regions of the equilibrium isotherm. The effects of salt type, salt and protein concentration, and temperature are reported. It was observed that under all conditions studied the adsorption process was entropically driven. This was contrary to expectations, since at the pH selected ion exchange is expected to dominate. A major driving force for the adsorption of BSA on the anion exchanger was concluded to be the increase in entropy from the release of water due to interactions between hydrophobic regions on the protein and adsorbent. The data further suggest that the conformational entropy change accompanying protein adsorption on the ion exchanger may also be significant.