光学吸收检测器检测池设计的研究进展（英文）

光学吸收检测器是液相色谱仪最常用的检测器之一,检测池是此种检测器的核心部分,是获得光穿过样品信息的重要部件,其设计影响检测器的性能。为了提高检测器的信噪比,减小检测池引起的色谱峰展宽,需要设计更长光程、更小体积的检测池,同时还要保证一定的光通量。受加工技术的限制,增大光程、减小池体积和保证光通量通常很难兼顾,这对优化检测池的设计和加工、提高检测器性能提出了挑战。本文以光学吸收检测器的检测原理为基础,从增大光程、减小体积、利用全反射等角度综述了检测池设计的研究进展,同时对部分检测池的设计进行了详细说明。这些不同的设计思路和结构对于检测池的设计以及光学吸收检测器的研发具有指导意义。     

电泳芯片无接触电导检测器的理论研究

目前电泳芯片大多数采用的是光学检测的方法,这为电泳芯片的微型化、一体化集成带来了一定的难度。为此,设计了一种新的电泳芯片高频无接触电导检测器,并对这种新型的检测器进行了理论研究和分析,建立了高频电导检测器等效电路模型,对高频电导检测器的结构进行了设计;综合考虑区带展宽等因素,确定了检测器的结构尺寸。该检测器具有应用范围广、结构简单、易于一体化集成的特点。     

毛细管电泳高频电导检测器的研制

设计了一种新的毛细管电泳检测器.根据高频电导滴定原理,将电导电极做成两个金属圆筒套于分离毛细管外,并向两个电极施加高频电压.经毛细管分离后的组分流过两个电极之间时,高频电流发生变化,得到毛细管电泳图.该检测器具有应用范围广、操作简便及重现性好等优点,已初步应用于混合无机离子的测定.     

毛细管电泳芯片简化安培检测系统的研制

摘要开发出一种新型电化学检测器,该检测器具有噪声低、基线漂移小、检测限低、整体体积小及便于现场使用等优点.在集成ITO电极的PDMS/玻璃毛细管电泳芯片上,利用多巴胺标准样品对该检测器的性能进行了评价.     

以多孔碳毡为工作电极的流动注射库仑检测器的研究及应用

本文设计了一个以多孔碳毡为工作电极的库化检测器并将其于用流动注射分析,以抗坏血酸、氢醌,没食子酸及二氧化硫为电活性物质检验该检测器的电化学特性。详细地研究了该检测器的库仑转换效率,选择性,线性范围,检测限及质量转移系数,并将该检测器作为双检测器流动注射分析系统中的“清除”电解池,用于酒中二氧化硫的测定,其结果与常规的吹气－氧化法非常吻合。     

高效液相色谱电生Mn(Ⅲ)化学发光法检测人体血清和尿样中的卡托普利

设计了一个HPLC在线电生Mn(Ⅲ)化学发光检测器, 实现在线电化学反应, 从而产生反应活性很高的初生态氧化剂Mn(Ⅲ), 并与色谱柱后CP混合产生化学发光. 同时还能够根据需要调节电极反应和发光反应两者的介质, 满足柱后发光反应的最佳环境. 在优化流动相和化学发光检测条件的基础上, 将该检测器应用于人体血清和尿液中CP的测定.     

新型色谱用微波等离子体离子化检测器的研究

自1965年McCormark提出微波等离子体应用于气相色谱法以来,人们相继研制出多种类型色谱用微波等离子体检测器,并在环保、医药、卫生等部门得到应用。在近几年研究工作的基础上,本文提出了我们新近研制的一种色谱用微波等离子体离子化检测器(MPID),并对检测器的一些分析特性进行了考察。 MPID的结构和工作原理 微波等离子体离子化检测器是我们自己设计和加工组装的,结构示意图见图1。     

多工作电极流动薄层电化学检测器及电解色谱

本文结合我们实验室所开展的一些工作,对多工作电极流动薄层电化学检测器及其电解色谱的一些新进展作了评述。着重介绍了三种结构类型即串联型、并联型和对向并列型的双工作电极检测器的设计和用途。本文还就双工作电极薄层电化学检测器与液相色谱结合的基本原理、优点和一些应用进行了讨论。最后简要地介绍了电解色谱的基本原理、进展及应用近况。     

供气相色谱仪使用的热导检测器的设计与实现

为了提高气相色谱仪用热导检测器的性能,设计了热导检测器的精密恒流源和差压检测电路。恒流源由场效应管IRF460、运算放大器AD8672和线性光耦HCNR201构成,低噪声电桥差压检测电路由2片AD8597构成。建立了差压检测电路的噪声模型,计算了噪声理论值。实际测试结果表明,该热导检测器的基线噪声达到4 μV, 50 min的基线漂移为15 μV,恒流源波动接近1 μA,优于现有热导检测器的技术指标。所介绍的设计方案和噪声分析方法对热导检测器的电路设计有较大的参考价值。     

凝胶色谱法测定氟醚橡胶相对分子质量及其分布

采用凝胶色谱法测定氟醚橡胶的相对分子质量及其分布.分别对单检测器(示差检测器)及三检测器(示差–光散射–黏度检测器)进行了方法研究.确立了以四氢呋喃为流动相,PLgel MIXED–B两柱串联,柱温为40℃,流量为1 mL/min的分析条件.利用本法测定聚苯乙烯标准物质的相对分子质量,测定值相对标准偏差均小于3％(n=...     

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.