神经节苷脂毛细管电泳的关键分离条件

神经节苷脂毛细管电泳的关键分离条件陈义（中国科学院化学研究所北京１０００８０）关键词毛细管电泳神经节苷脂环糊精神经节苷脂在水溶液中易形成混合胶束［１～３］，通常不被毛细管电泳（ＣＥ）分离。Ｙｏｏ等［４］提出用一级添加剂的方法来促进分离，并发现α－ＣＤ...     

苯胺及其衍生物的毛细管电泳行为研究

采用紫外吸收检测，毛细管电泳分离，研究了九种苯胺及其衍生物在毛细管区带电泳(CZE)体系和胶束电动毛细管色谱(MECC)体系中的行为特征。讨论了缓冲溶液的浓度与pH、胶束浓度及混合胶束等在不同体系中对分离组分的影响，发现在CZE体系中，控制分离的主要因素是pKb值；在MECC体系中，控制分离的主要因素是溶质分子中碳原子数。建立了一种分离测定九种苯胺及其衍生物的高效毛细管电泳方法。     

寡糖的毛细管电泳分析

多种寡糖经α－萘胺衍生化后，用硼砂作为电泳介质，实现了高效毛细管电泳分离。比较了毛细管区带电泳和胶束毛细管电动色谱分离寡糖α－萘胺衍生物的电泳行为，对影响分离度的诸因素进行了考察，选择了最佳分离条件。     

应用毛细管电泳法分离测定6种取代苯化合物

采用毛细管电泳法对六种取代苯化合物进行了分离研究，考察了3种电泳模式对分离的影响。环糊精的胶束毛细管电泳法可使各组分达到基线分离，正交设计法得到了最佳实验条件，在质量浓度为30－300mg/L的范围内，可进行定量分析，该方法已应用于废液中苯类化合物的测定。     

无电渗流的毛细管电泳

无电渗流毛细管电泳是毛细管电泳的一种新技术。本文对基产生条件及其在毛细管区带电泳与胶束电动毛细管色谱中的分离特点进行了详细介绍。     

胶束电动毛细管色谱法分离酮康唑手性异构体

1引言胶束电动毛细管色谱法（MECC）综合了反相高效液相色谱的分配机理和毛细管区带电泳的电渗及电泳机理,实现了对电中性物的分离。由于环糊精（CD）外表面具有亲水性,当其与胶束共存时,不能进入胶束,所以溶液存在三相即：胶束相、水相和CD相。异构体通过与CD形成不同稳定常数的主-客体络合物而达到手性识别,由于十二烷基硫酸钠（SDS）的高疏水性,该方法对分离电中性和疏水性化合物具有突出的优越性。酮康华（ketoconazole）属口服咪唑类抗真菌合成药物,到目前为止,人们对其它手性药物拆分进行了较多的研究,但对酮康唑的研…     

泽泻乙醇提取物的HPCE分离研究

采用高效毛细管电泳的胶束电动毛细管色谱的分离模式(MEKC),对泽泻的乙醇(95％)提取物进行分离研究。以十二烷基硫酸钠(SDS)胶束为准固定相．硼砂为缓冲体系,甲醇为有机添加剂,考察了SDS浓度、硼砂浓度、pH、甲醇用量、电泳电压、电泳温度等对分离的影响。结果表明：硼砂缓冲体系为运行缓冲溶液(pH：9．18～9．20)、硼砂浓度30mmoL／L、SDS浓度45mmol／L、甲醇体积分数30％,分离电压25kv、分离温度25℃时分离效果最好。在此条件下,得到分离度和重现性均较好的泽泻乙醇提取物的HPCE色谱图。     

高效毛细管电泳的电导检测和紫外光度检测研究

本文自制商效毛细管电泳装置.研究了毛细管区带电泳电导检测和毛细管胶束电动色谱紫外光度检测。在电导检测中,制作铂丝微电导池,并由用电池隔膜制作的导电接口连接电泳毛细管和电导池,高压被有效隔离,实现柱后电导检测,用内径200μm、长70cm(到接口)石英毛细管在10kV电压下分离检测Li~-、Na~-、K~-。在电动色谱中将高效液相色谱仪与高压电源组成电泳装置,用内径100μm,长50cm(到检测器)石英毛细管和SDS胶束溶液在14kV电压下分离检测电中性化合物。     

基于胶束反向扫集的毛细管电泳量子点电化学发光研究

研究了胺分子对CdSe量子点电化学发光的增强作用，构建了CdSe量子点电化学发光传感器.结合胶束扫集预富集技术，发展了一种基于胶束反向扫集的毛细管电泳（CE）量子点（QD）电化学发光（ECL）新方法用于莱克多巴胺和克伦特罗的同时分离检测.毛细管内首先充满含有十二烷基硫酸钠（SDS）胶束的缓冲溶液，电动进样时，样品分子进入毛细管，在入口端被迎面而来的SDS胶束捕获并富集，经CE分离后顺次进入检测端，根据不同浓度的胺分子对CdSe量子点发光强度的增强作用不同，实现对不同胺分子的同时分离检测.胶束反向扫集富集技术，使胶束-样品结合物在毛细管中处于准静止状态，进样时间可达50 min，量子点电化学发光信号增强6000倍.该方法成功用于猪肉样品中莱克多巴胺和克伦特罗的同时分离检测，其线性范围分别为（0.8~2960）和（3.0~5520）μg/L，检出限分别为96.8和192.5 ng/L.     

芯片国管电泳及其在生命科学中的应用

芯片毛细管电泳（Chip-CE)技术在近几年已取得了很大的进展。本文着重介绍芯片毛细管区带电泳技术，对等电聚焦、等速电泳、自由溶液电泳及胶束电动色谱等其它芯片电泳模式也有所提及。讨论了芯片材料和制作技术、芯片的几何形状、样品的操作和衍生、检测及芯片毛细管电泳技术的应用，特别是在核酸和蛋白质的分离分析中的进展。     

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%.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

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.