新型共聚物涂层毛细管电泳柱及其分离蛋白质的研究

研究新型共聚物——ＺＢ系列表面键合剂在毛细管电泳中的应用。采用物理吸附的方法制备了ＺＢ－００４,ＺＢ－０１４,ＺＢ－０１６等３种涂层毛细管柱,在ｐＨ３～５范围内,３种涂层均能有效地降低管壁对蛋白质的吸附作用和电渗流,其中亲水性较弱的ＺＢ－００４涂层的分离性能最好。在ｐＨ＜５时,涂层具有较高的稳定性和良好的分析重复性,但在更高的ｐＨ值条件下,仍然存在着峰形畸变和电渗流迅速增加的现象。     

用聚丙烯酰胺交联涂层毛细管电泳柱分离无机阴离子

研究了用涂层柱分离Ｉ＾－，ＮＯ＾－２，ＮＯ＾－３，ＳＣＮ＾－，ＭｏＯ＾２－４等５种具有紫外吸收的阴离了的毛细管电泳方法。采用涂层柱可以有效地抑制电渗流，因此无需在载体电解质溶液中加入电流改性剂。其优越性在于改善了由于电渗流改性剂与体积较大的阴离子发生离子对相互作用所导致的峰形拖尾现象，有助于准确定理。     

杂原子分子筛B－ZSM－5的合成与表征

在碱性介质（ｐＨ＝１０）中，用四丁基溴化铵、硅溶胶、硼酸在水溶液中合成了一种新型杂原子分子筛──Ｂ－ＺＳＭ－５型分子筛。用Ｘ射线衍射、扫描电镜、热重等方法进行了表征和研究。     

MoO3／HBZSM—5催化剂上甲烷的无氧芳构化反应

以含硼杂原子分子筛ＨＢＺＳＭ－５为载体,考察了其担载ＭｏＯ３后催化甲烷无氧芳构化反应的性能,并结合ＸＲＤ,ＩＲ,ＴＧ和ＳＥＭ等手段对催化剂进行了表征。实验结果表明,ＭｏＯ３／ＨＢＺＳＭ－５催化剂具有较高的甲烷芳构化活性,但稳定性较差,随着引入分子筛骨架中硼量的增大,甲烷的极值转化率增高;随着反应温度的升高,ＭｏＯ３／ＨＢＺＳＭ－５催化剂的甲烷芳构化活性升高。从产物分布的变化来看,硼的引入对于催化剂     

沸石催化剂上醇的醚化反应

研究了乙醇，正丁醇，仲丁醇和正戊醇有ＺＳＭ－５和Ｂｅｔａ沸石上的醚化反应。用ＮＨ３－ＴＰＤ和ＩＲ测定了ＺＳＭ－５沸石的表面酸性，讨论了沸石表面Ｂ酸和Ｌ酸和与醚化活性的关系。结果表明，乙醇的脱水反应既可以在Ｂ酸中心上进行，也可以在Ｌ酸中心中心上进行，既可以在强酸中心上进行，亦可以在弱酸中心上进行。     

植酸在络合滴定铜时作为掩蔽剂的研究

研究了植酸在络合滴定铜时的掩蔽性能。发现在ｐＨ５．５或ｐＨ４．５以５－Ｂｒ－ＰＡＤＡＴ为指示剂,用ＥＤＴＡ滴定Ｃｕ＾２＋时,可以用植酸掩蔽Ｆｅ＾３＋、Ａｌ＾３＋,Ｓｎ＾４＋、Ｔｉ＾４＋、Ｔｈ＾４＋、Ｌａ＾３＋和Ｃｅ＾３＋。本法已用于测定锡青铜,磷青铜和铝青铜中的铜。     

综合练习三参考答案

综合练习三参考答案一二二、盗杨日四、２７．ＣｔｉＺＯ;ＩＣＵＯ——ＺＣｌｌＺＯ－－Ｉ－－ＯＺ２８．（）③（２）］一５—６—２—３—４（３）Ｈ。ＳＯ;ｔ－ＺＨＢｒ。Ｂｒ。ｔ４ＳＯ。ｆ＋ＺＨ。ＯＣ。Ｈ。ＯＨ———、ＣＨＺ。ＣＨＺ千十ＨＺＯ浓Ｈ。ＳＯ’ＺＣ...     

水杨酸及其氯代物的毛细管电泳分析研究

建立了分析水杨酸、５－氯代水杨酸、三氯水杨酸等水杨酸类化合物的毛细管区带电泳法（ＣＺＥ）。讨论了电压、缓冲溶液的浓度和ｐＨ值对分析结果的影响。其中缓冲溶液的ｐＨ值对分析结果的影响最为显著。ｐＨ〈７．４０时,三种化合物的出峰顺序为：三氯水杨酸、５－氯代水杨酸、水杨酸;当ｐＨ〉７．４０时,三种化合物的出峰顺序为：５－氯代水杨酸、水杨酸、三氯水杨酸。水杨酸、５－氯代水杨酸、三氯水杨酸的检出限分别为０．１     

吡啶—2,6—二羧酸体系导数荧光法同时测定铀,钐,铕,铽,镝

本研究了吡啶－２，６－二羧酸（ＤＰＡ）体系导数荧光法同时测定铀，钐，铕，铽，镝的最佳条件。在ｐＨ５．５，４．８×１０＾－＾５ｍｏｌ／ＬＤＰＡ，激发波长２７２ｎｍ的条件下，可分别在５１８，６３９，６２１，５３９和６６ｎｍ处测定铀，钐，铕，铽和镝，检测限分别达到７，０．４，０．００４，０．０２６和０．２５ｎｇ／ｍＬ。应用本法测定了混合成试液中上术五种离子含量，回收率为９２．３－１０８．１％。     

正电荷聚合物动态涂敷毛细管电泳柱对碱性蛋白的分离

以１，５－二甲基－二杂氮十一烷亚甲基聚Ｎ－甲溴化物（ＨＤＢ）为添加剂对毛细管柱进行动态修饰，对４种碱性蛋白质进行分离。实验结果表明：ＨＤＢ可使电渗流（ＥＯＦ）反转，很好地抑制了碱性蛋白质在石英毛细管壁上的吸附。ＨＤＢ浓度（Ｗ／Ｖ）为０．０１２％，ｐＨ４．０～８．０之间时平均柱效为１．０ ×１０~５～１．５×１０~５理论塔板数／ｍ。每次运行之间（ｎ＝６），天与天之间（ｎ＝６），迁移时间的相对标准偏差（ＲＳＤ）分别小于１％和４％，表明该动态涂敷方法具有良好的重现性和稳定性。     

Capillary electrophoresis using core‐based hyperbranched polyethyleneimine (CHPEI) static‐coated capillaries

With unique 3‐D architecture, the application of core‐based hyperbranched polyethyleneimine (CHPEI), as a capillary coating in capillary electrophoresis, is demonstrated by manipulation of the electroosmotic mobility (EOF). CHPEI coatings (CHPEI5, M_w ≈? 5000 and CHPEI25, M_w ≈? 25 000) were physically adsorbed onto the inner surface of bare fused‐silica capillary (BFS) via electrostatic interaction of the oppositely charged molecules by rinsing the capillaries with different CHPEI aqueous solutions. The EOF values of the coated capillaries were measured over the pH range of 4.0–9.0. At higher pH (pH >6) the coated capillary surface possesses excess negative charges, which causes the reversal of the EOF. The magnitudes of the EOF obtained from the coated capillaries were three‐fold lower than that of BFS capillary. Desirable reproducibility of the EOF with % RSD (n = 5) ? 2 was obtained. Effect of ionic strength, stability of the coating (% RSD = 0.3) and the dependence of the EOF on pH (% RSD = 0.5) were also investigated. The CHPEI‐coated capillaries were successfully utilized to separate phenolic compounds, B vitamins, as well as basic drugs and related compounds with reasonable analysis time (<20 min) and acceptable migration‐time repeatability (<0.7% RSD for intra‐capillary and <2% RSD for inter‐capillary).     

A novel cationic triblock copolymer as noncovalent coating for the separation of proteins by CE

A novel noncovalent adsorbed coating for CE has been prepared and explored. This coating was based on quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(ethylene oxide)-block-poly(2-(dimethylamino)ethyl methacrylate) (QDED) triblock copolymer which was synthesized by atomic transfer radical polymerization (ATRP) in our laboratory. The polycationic polymer and the negatively charged fused-silica surface attracted each other through electrostatic interactions and hydrogen bonds. It was demonstrated that the coated capillaries provided an electroosmotic flow with reverse direction, and the magnitude of the electroosmotic flow can be modulated by varying the molecular mass of poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) block and pH value of the buffer. The effects of the molecular mass of PDMAEMA block in QDED triblock copolymer and pH value of the buffer on the separation of basic proteins were investigated in detail. The triblock copolymer coatings showed higher separation efficiency, better migration time repeatability and would apply to wider range of pH than bare fused-silica capillary when used in separating proteins. Proteins from egg white were also separated through this QDED triblock copolymer-coated capillary. These results demonstrated that the QDED triblock copolymer coatings are suitable for analyzing biosamples.     

Open‐tubular capillary electrochromatographic determination of ten sulfonamides in tap water and milk by a metal‐organic framework‐coated capillary column

In this study, a metal‐organic framework (MOF), [Mn(cam)(bpy)], was synthesized and characterized by thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectrometry. An open‐tubular capillary column was fabricated from [Mn(cam)(bpy)] via the amide coupling method. Ten types of sulfonamides were separated through the fabricated capillary column, which showed a good limits of detection (<0.07 μg/mL) and linear ranges (1–100 or 5–100 μg/mL) with a high correlation coefficients (R² > 0.9987). The intra‐day, inter‐day and column‐to‐column relative standard deviations (RSDs) in the migration times ranged from 0.44 to 4.87%, and the peak area RSDs ranged from 0.80 to 7.28%. The developed capillary electrochromatography method can be successfully utilized for the determination of sulfonamides in tap water and milk samples.     

Organotin polymers—II.Copolymerization parameters for tributyltin methacrylate with methyl acrylate,ethyl acrylate,butyl acrylate and acrylonitrile

Copolymerizations of tributyltin methacrylate (M₁) with methyl acrylate, ethyl acrylate, n-butyl acrylate and acrylonitrile were carried out in solution at 70° using azobisisobutyronitrile as initiator. Copolymer compositions were determined by tin analysis; monomer reactivity ratios were calculated by Fineman-Ross and Kelen-Tüdös methods. The reactivities of acrylic esters decrease as the alkyl group becomes bulkier. Azeotropic copolymers could be formed from tributyltin methacrylate with butyl acrylate and with acrylonitrile. The structures of M₁ and its azeotropic copolymers have been investigated by infrared spectroscopy.     

Vinyl polymerization. 410. Polymerizations of vinyl monomers initiated by poly(styrene-co-sodium acrylate) or poly(methyl methacrylate-co-sodium methacrylate). A verification of the concept of hard and soft hydrophobic areas and monomers

It was found that the copolymers of sodium acrylate (AA-Na) with styrene (St) and of sodium methacrylate (MAA-Na) with methyl methacrylate (MMA) could polymerize vinyl monomers in an aqueous phase without the usual initiator. Interestingly, there was a definite composition of the copolymer for the polymerization of a given monomer; for example, when poly(St-co-AA-Na) was used, St, MMA, vinyl acetate, ethyl acrylate, methyl acrylate, and acrylonitrile were polymerized by the copolymer having mole ratios of AA-Na:St of 0.61:0.29, 0.47:0.53, 0.38:0.62, 0.30:0.70, 0.24:0.76, and 1.00:0, respectively. The copolymers of various compositions can form hydrophobic areas (HAs) in the water phase. As has been repeatedly reported, the polymerization proceeds in the HAs, and the following new hypothesis was recently proposed that the hard (the less hydrophilic) HA prefers to incorporate the hard monomer and the soft (the less hydrophobic or the more hydrophilic) HA prefers to incorporate the soft monomer. The results mentioned above support this hypothesis.     

Connections between structure and performance of four cationic copolymers used as physically adsorbed coatings in capillary electrophoresis

In this work, the properties of four cationic copolymers synthesized in our laboratory are studied as physically adsorbed coatings for capillary electrophoresis (CE). Namely, the four copolymers investigated were poly(N-ethyl morpholine methacrylamide-co-N,N-dimethylacrylamide), poly(N-ethyl pyrrolidine methacrylate-co-N,N-dimethylacrylamide), poly(N-ethyl morpholine methacrylate-co-N,N-dimethylacrylamide) and poly(N-ethyl pyrrolidine methacrylamide-co-N,N-dimethylacrylamide). Capillaries were easily coated using these four different macromolecules by simply flushing into the tubing an aqueous solution containing the copolymer. The stability and reproducibility of each coating were tested for the same day, different days and different capillaries. It is demonstrated that the use of these coatings in CE can drastically reduce the analysis time, improve the resolution of the separations or enhance the analysis repeatability at very acidic pH values compared to bare silica columns. As an example, the analysis of an organic acids test mixture revealed that the analysis time was reduced more than 6-times whereas the separation efficiency was significantly increased to nearly 10-times attaining values up to 595,000 plates/m using the coated capillaries. Moreover, it was shown that all the copolymers used as coatings for CE allowed the separation of basic proteins by reducing their adsorption onto the capillary wall. Links between their molecular structure, physicochemical properties and their performance as coatings in CE are discussed.     

Controlled copolymerization of acrylonitrile in bulk via the reversible addition-fragmentation chain-transfer mechanism

The pseudoliving radical binary copolymerization of acrylonitrile with methyl acrylate, styrene, n-butyl acrylate, and tert-butyl acrylate in bulk in the presence of the reversible addition-fragmentation chain-transfer agent dibenzyl trithiocarbonate is performed for the first time. The addition of trithiocarbonate makes it possible to prepare a narrowly dispersed visually optically transparent copolymer in a wide range of monomer-feed compositions even at limiting conversions. Conditions for the synthesis of acrylonitrile copolymers with controlled molecular masses and narrow molecular-mass distributions are ascertained. In the above copolymers, the trithiocarbonate group is shown to be located within the chain.     

Fast and easy coating for capillary electrophoresis based on a physically adsorbed cationic copolymer

In this work, a new copolymer synthesized in our laboratory is used as physically adsorbed coating for capillary electrophoresis (CE). The copolymer is composed of ethylpyrrolidine methacrylate (EPyM) and methylmethacrylate (MMA). The capillary coating is easily obtained by simply flushing into the tubing an EPyM/MMA solution. It is demonstrated that the composition of the EPyM/MMA copolymer together with the selection of the background electrolyte (BGE) and pH allow tailoring the direction and magnitude of the electroosmotic flow (EOF) in CE. It is also shown that the EOF obtained for the EPyM/MMA-coated capillaries was reproducible in all cases independently on pH or polymer composition. Thus, RSD values lower than 1.9% (n=5) for the same capillary and day were obtained for the migration time, while the repeatability interdays (n=5) was observed to provide RSD values lower than 0.5%. The stability of the coating procedure was also tested between capillaries (n=3) obtaining RSD values lower than 0.6%. It is demonstrated with several examples that the use of EPyM/MMA coatings in CE can drastically reduce the analysis time and/or to improve the resolution of the separations. It is shown that EPyM/MMA-coated capillaries allow the separation of basic proteins by reducing their adsorption onto the capillary wall. Also, EPyM/MMA-coated capillaries provide a faster separation of samples containing simultaneously positive and negative analytes. Moreover, it is demonstrated that the use of EPyM/MMA-coated capillaries can incorporate an additional chromatographic-like interaction with nucleosides that highly improves the separation of this group of solutes.     

BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate(EA) as comonomer (5--23 wt%) was prepared by free-radical copolymerization. The per-meability coefficients of the copolymers to oxygen and carbon dioxide were measured at1.0 MPa and at 30℃, and those to water vapor also measured at 100% relative humidityand at 30℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate contentincrease, the permeability coefficients of the copolymers to oxygen and carbon dioxide areincreased progressively but those to water vapor are decreased progressively The gas per-meability coefficients of the polymers were correlated with free-volume fractions or the ratioof free volume to cohesive energy.