毛细管电泳无接触电导检测研究进展

毛细管电泳(CE)电导检测(CD)是相对较灵敏和仪器结构简单的一项溶液分析技术,尤其是对于无生色团的无机离子分析更具有突出优势,因此,CE-CD技术近年来得到了较快发展[1],并已推出商品化的毛细管电泳电导检测器[2]。但CE和CD的偶联目前还存在如下几个问题:第一,加工适合于毛细管     

一种组装的毛细管电泳系统

毛细管电泳(Capillary Electrophoresis,CE)作为一种新兴的高效快速分离分析技术近年来发展极为迅速,国外已经有多种CE整机实现了商品化,并开始进入中国市场。这些CE仪器各具特色,应用也非常成功。但对于国内用户来说,价格显然太     

毛细管电泳电化学发光检测体系中正高压进样条件下正负离子电场放大进样效应

毛细管电泳 (CE)正向着实际体系分析和微型化分析的方向发展[1,2 ] .为提高分离效率 ,CE的进样量一般很小 (1 0 - 12 ～ 1 0 - 9L ) ,因此常采用在线样品富集方式以提高检测灵敏度 .电场放大进样 (FASI)是 CE中实现在线样品富集的简便方式[3] ,随着 CE和检测技术的发展 ,其应用范围和研究体系不断扩大[4 ] .三联吡啶钌 [Ru(bpy) 2 + 3]电化学发光 (ECL )作为一种高灵敏、高选择性的检测方法被逐渐应用于 CE分析 (CE-ECL) .我们对这种技术进行了研究 ,并将其应用于临床分析[5～ 7] .实验中发现 ,在施加正高压的条件下 ,不同进样条…     

毛细管电泳法在手性分离中的应用及进展

近年来,毛细管电泳(CE) 手性分离方法的研究主要集中在各种手性添加剂与对映体药物的匹配及实验条件的最优化选择上.目前,较为成熟的CE分离模式有:区带电泳(CZE)、凝胶电泳(CGE)、等速电泳(CITP)、胶束电动色谱(MEKC)和非水电泳(NACE)等,并已成功地用于手性化合物对映体的分离.CE手性分离研究正朝着新型手性选择剂的研制和实现与其他各种定性分析仪器及其他色谱分离模式的联用方向发展.     

毛细管电泳吡啶钌电化学发光检测天仙子中生物碱

1 引言 天仙子是一种天然中草药,它的主要活性成分为阿托品和东莨菪碱 .目前,分析天仙子的方法主要有:核磁共振技术、紫外分光光度法、高效液相色谱法和毛细管电泳分离法等.毛细管电泳技术(CE)具有进样体积小、分离效率高等优势.吡啶钌(Ru(bpy)2+3)电化学发光法具有激发态寿命长、发光效率高、试剂可循环再生等优点. CE与Ru(bpy)2+3电化学发光联用技术(CE-ECL)将二者优势有机组合,已成为分析化学领域中很好的分析工具.     

CAPILLARY ELECTROPHORETIC SEPARATION OF GANGLIOSIDES USING CYCLODEXTRIN AS BUFFER ADDITIVE

A new method for the rapid separation of gangliosides(GLS)by capillaryelectrophoresis(CE)is described which is based on the use of β—cyclodextrin(β—CD)asbuffer additive.The effects of β—CD concentration,pH,electrolyte composition were dis-cussed.Under optimum conditions,the complete separation of a mixture of GM1,GD1a,GD1b and GT1b was obtained within 5 min.     

Synthesis and Characterisation of Water-Soluble Carboxymethyl-Cyclodextrin Polymer as Capillary Electrophoresis Chiral Selector

Cyclodextrin (CD) and its water-soluble derivatives have been used as chiral selectors incapillary electrophoresis successfully. Among them, the water-soluble CD polymerperforms intramolecular synergistic effect in CE chiral separation and thecarboxymethyl-CD (CM-CD) migrates in the opposite direction of the electroosmoticflow because of its negative charge in water. It is interesting to synthesizecarboxymethyl-CD polymer (CM-CD polymer), which has properties of both the neutralCD poly…     

2018年毛细管电泳技术年度回顾

本文归纳总结了ISI Web of Science中检索的2018年度毛细管电泳（CE）技术相关的研究论文，并从生命科学研究、药物分析、手性拆分、医学及临床检验、CE相关仪器改进、食品安全检验和环境监测7个方面进行分类说明；介绍了2018年度涉及CE技术的8个会议情况；补充了国内外现行的CE技术标准。最后，列出了主要的国产毛细管电泳仪型号。     

毛细管电泳在毒品分析中的应用

综述了近年来毛细管电泳(CE)在毒品分析中的应用进展,介绍了不同的CE模式并给出了应用实例,展望了CE在毒品分析中的应用前景.     

聚丙烯酸酯类毛细管整体柱的制备及其在加压毛细管电色谱中的应用

毛细管电色谱(CEC)是毛细管电泳(CE)和微径液相色谱(micro—HPLC)技术的结合,是集CE的电子迁移机制和micro-HPLC的分配分离机理发展起来的一种高效微分离技术．CEC以塞子流型的电渗流代替抛物线流型的压力流,具有CE的高效性,能够分离电中性化合物而具有HPLC的高选择性．     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.