毛细管电泳的微机化安培法检测

毛细管电泳的微机化安培法检测胡深，李培标，程介克（武汉大学化学系，武汉，４３００７２）关键词毛细管电泳；微电极；安培法检测；微型计算机安培法电化学检测器用于毛细管电泳有独特的优点，如线性范围宽，选择性好，可以进行生物微环境电活性物质的分离检测［１，２...     

一种新型毛细管电泳柱端喷壁安培检测池

提出一种新型毛细管电泳柱端喷壁安培检测池。它制作简单，操作容易，具有很好的重现性和灵敏度。用这种安培检测池，可以不使用微动平台很容易地将工作电极与分离毛细管出口对准。为评价该安培检测池的分析性能，用毛细管电泳柱端安培检测法分别检测了酚、儿茶酚胺和芳香胺。考察了电动进样时间、分离电压以及毛细管出口与电极的间距对响应电流和分离效能的影响。通过对酚和儿茶酚胺测定的重现性、浓度线性范围及检出限的考察，结果表明该安培池是精密可靠的。同时，用该安培池对标准加入于血浆样品中的多巴胺（ＤＡ）、去甲基肾上腺素（ＮＥ）和原儿茶醛（ＰＡ）进行了测定，结果令人满意。     

高效毛细管电泳安培检测的进展

本文对高效毛细管电泳电化学检测方法中的安培检测进行了评述，安培检测具有灵敏度高，选择的特点，安培检测根据毛细管内径的大小有离柱安培检测和柱端安培检测，近年来脉冲安培分析法、化学修饰电极也已被引入毛细管电泳电化学检测。     

毛细管电泳安培法检测中的在柱场放大效应

本文首次报道用安培电化学检测器探讨毛细管电泳分离的场放大进样效应，分析了系统峰的形成以及场放大进样对电泳分离检测的影响。采用２５μｍ内径毛细管电泳分离，对去甲肾上腺素（ＮＥ）和儿茶酚（ＣＡＴ）分别可达０．４ｎｍｏｌ／Ｌ和１．５ｎｍｏｌ／Ｌ的浓度检测限，有效提高了毛细管电泳安培法检测的灵敏度。     

毛细电泳安培检测技术进展

对毛细管电泳离柱和柱端安培检测方式、不同形式电极在安培检测中的应用、安培检测在芯片毛细管电泳中的应用、安培检测池等内容进行了总结和讨论，并预测了安培检测技术未来发展方向。     

用于高效毛细管电泳的电化学检测器

阐述了高效毛细管电泳电化学检测器（包括电导、电势和安培检测）的研究现状，重点是检测器的研制及接口的制作技术。对各种电化学检测器的应用情况也进行了总结。展望了高效毛细管电泳电化学检测的发展前景。     

毛细管电泳安培检测技术进展

对毛细管电泳离柱和柱端安培检测方式、不同形式电极在安培检测中的应用、安培检测在芯片毛细管电泳中的应用、安培检测池等内容进行了总结和讨论 ,并预测了安培检测技术未来发展方向     

毛细管电泳多道电化学检测器的研制及其应用

报道了毛细管电泳多道电化学检测器的研制及其应用，安培检测器和电导检测器并联在同一毛细管电泳检测系统中，在同一缓冲体系，同一工作电极下对同一复杂的分析体系同时进行电导和安培检测；整个装置综合了电导检测和安培检测两种检测器的优点，性能优良，造价低廉，对实际样品的检测取得了令人满意的结果。     

毛细管电泳安培及电导检测最新进展

对毛细管电泳安培检测和电导检测的研究近况进行了综述,分别介绍了电导法和安培法与毛细管电泳的联接及应用,并对其发展方向作了展望。     

芯片毛细管理电泳中组分的迁移行为及其特征

在自组装的芯片毛细管电泳-激光透导荧光检测装置上，以单个染料和一组荧光素异硫氰酸酯（FITC）标记的氨基酸为对象。研究了芯片毛细管电泳与传统毛细管电泳之间的差别，考察了玻璃芯片上微通道内的伏安特性以及抑制电压、进样方式和检测点的位置等对芯片毛细管电泳分离分析的影响，特别注意到了其有别于传统毛细管电泳的各种行为特征。     

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%.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.