高效毛细管电泳I. 分析化学中的一个新的前沿领域

本文是关于高效毛细管电泳(HPCE)的详细综述的第一部分,概括了HPCE技术发展的历史、国内外研究现状,总结了HPCE的基本原理、主要操作方式以及HPCE所具有的特点,并讨论了该技术目前存在的问题及可能的解决方法。     

高效毛细管电泳Ⅱ. 最新进展

自80年代末高效毛细管电泳(HPCE)引起广泛重视以来,经过短短5年的时间。它在理论、仪器以及应用技术方面都已取得了高速的发展,并正在走向成熟。本文作为HPCE详细综述的第二部分,介绍HPCE在技术和应用方法方面的进展。     

21世纪毛细管电泳技术及应用发展趋势

在21世纪，毛细管电泳技术面临着新的挑战和机遇，在其检测手段，仪器的小型化和集成化，以及分离模式上都存在着极大的发展空间，文中针对这三方面的发展趋势和毛细管电泳的应用进行了讨论。     

毛细管电泳用于胞嘧啶脱氨反应动力学研究

DNA中的胞嘧啶在化学致变剂作用下会发生脱氨反应，被认为是导致基因损伤的重要原因之一，本文采用毛细管电泳测定胞嘧啶和尿嘧啶，并将此种新方法用于过氧化氢存在下胞嘧啶脱氨反应的动力学研究，结果显示该反应对过氧化氢和胞嘧啶均为一级反应，反应活化能为70.35kJ.mol^-1，明显低于自发脱氨反应，表明过氧化氢可以加速胞嘧啶脱氨反应。     

糖类的毛细管电泳及芯片毛细管电泳

 糖类化合物在生物体内发挥多方面的作用。糖研究的复杂性在于其结构的复杂多变。高效毛细管电泳作为一种快速、高效的分离分析手段已广泛应用于糖的研究。芯片毛细管电泳是近几年来发展起来的新的分析技术 ,并已经在生命科学的研究中得到较广泛的应用。就各种糖类化合物的毛细管电泳的分析策略、检测条件及糖类化合物的芯片毛细管电泳进行了阐述 ,共 4 8篇。     

基于电迁移率差异而分离的新型聚焦电泳技术

基于电迁移率差异而分离的新型聚焦电泳技术①陈东英林华水周勇亮毛秉伟谢兆雄卓向东田昭武＊（固体表面物理化学国家重点实验室及化学系厦门大学厦门３６１００５）毛细管区带电泳已成为十几年来发展最快的分离分析技术．Ｈｊｅｒｔéｎ于１９６７年在玻璃管中进行了自由...     

毛细管区带电泳

一、历史与现状 毛细管区带电泳(CZE)或高效毛细管电泳(RPCE)是继色谱之后的又一高效快速分析方法,近年来发展极快(图1)。CZE的研究热潮正在英国掀起,并向其他国家扩展。CZE是第六届国际等速电泳会议的主题之一,在88年的Pitts-burg会上受到高度重视。其首届专题国际会议也     

集成毛细管电泳芯片研究进展

 介绍了一种多功能化的快速、高效、高灵敏度和低耗的微型装置集成毛细管电泳芯片的发展和最新研究动向 , 39篇。     

亲和毛细管电泳技术及其应用

对近几年新发展起来的亲和毛细管电泳技术（ACE）的原理、分类及方法作了简要介绍,着重介绍了亲和毛细管区带电泳、毛细管亲和凝胶电泳、胶束电动色谱中的亲和电泳、亲和毛细管等电聚焦、亲和探针毛细管电泳等过程和方法。对ACE在分子生物学、生物化学中的应用及该技术在亲和常数测定、核酸片段识别、竞争免疫分析、药物先导化合物的筛选等方面的应用也作了介绍。     

Flow “Fine” Synthesis: High Yielding and Selective Organic Synthesis by Flow Methods

The concept of flow “fine” synthesis, that is, high yielding and selective organic synthesis by flow methods, is described. Some examples of flow “fine” synthesis of natural products and APIs are discussed. Flow methods have several advantages over batch methods in terms of environmental compatibility, efficiency, and safety. However, synthesis by flow methods is more difficult than synthesis by batch methods. Indeed, it has been considered that synthesis by flow methods can be applicable for the production of simple gasses but that it is difficult to apply to the synthesis of complex molecules such as natural products and APIs. Therefore, organic synthesis of such complex molecules has been conducted by batch methods. On the other hand, syntheses and reactions that attain high yields and high selectivities by flow methods are increasingly reported. Flow methods are leading candidates for the next generation of manufacturing methods that can mitigate environmental concerns toward sustainable society.     

Linear-scaling computation of excited states in time-domain

The applicability of quantum mechanical methods is severely limited by their poor scaling.To circumvent the problem,linearscaling methods for quantum mechanical calculations had been developed.The physical basis of linear-scaling methods is the locality in quantum mechanics where the properties or observables of a system are weakly influenced by factors spatially far apart.Besides the substantial efforts spent on devising linear-scaling methods for ground state,there is also a growing interest in the development of linear-scaling methods for excited states.This review gives an overview of linear-scaling approaches for excited states solved in real time-domain.     

橡胶贮存寿命预测方法研究进展与思考建议

概述了用数学模型法预测橡胶贮存寿命的方法,包括阿伦尼斯模型,用ASTM D412评估橡胶拉伸性能,应力应变老化模型,压缩永久变形的预测方法,橡胶疲劳寿命损伤模型,用有限元法考核橡胶的裂纹长度与抗裂能之间的关系,基于叠加原理的寿命预测模型等,针对上述模型预测研究结果提出了相关思考建议。认为以老化动力学为基础预测材料寿命的数学模型法发展非常迅速,建议深入研究并拓宽应用;在透彻了解和掌握必需的分子结构参数的基础上,如果结合计算机技术模拟长期贮存或使用条件,对橡胶老化反应机理的研究可能是一个有前景的发展方向。     

Rapid ultraviolet spectrophotometric and liquid chromatographic methods for the determination of natamycin in lactoserum matrix

Two rapid and simple methods were developed for the determination of natamycin in lactoserum matrix by ultraviolet (UV) spectrophotometry and liquid chromatography (LC) with diode-array detection. The methods involve protein precipitation with methanol, followed by centrifugation. No cleanup is necessary. The applicable concentrations of natamycin in lactoserum range from 2 to 500 mg/L for samples analyzed by both methods. The detection and quantitation limits are 0.07 and 0.23 mg/L, respectively, for the UV spectrophotometric method and 0.1 and 0.32 mg/L, respectively, for the LC method. The methods were applied satisfactorily to the determination of natamycin in various commercial lactosera. Both methods were validated independently by standard additions and Youden methodologies, which verified their accuracy. Once the 2 proposed methods were validated independently, the validation of one method was carried out with the other.     

The determination of fluoride in environmentally relevant matrices

This report covers analytical methods for the determination of total fluoride in gaseous emissions, rain water and aqueous effluents, vegetation, human urine, factory air and environmental air. All the methods are based on final measurement of fluoride by means of the fluoride ion-selective electrode. Interferences which cannot be eliminated by the masking power of the TISAB buffer solution are avoided by separation of fluoride by steam distillation. Decomposition methods are used for vegetation and for samples which may contain insolubles such as stack gases or aqueous effluents. Sampling of fluoride from air is done by alkaline absorption for the high concentration range (stack gases) and by filter methods for low fluoride concentrations, e.g., in factory and environmental air. Detection limits as low as 0.3 μg m^?3 fluoride can thus be achieved. The methods were established after the individual analytical procedures, common in the various member countries of CTEF, had been compared. Thus, the most practicable method was selected or an optimized version was designed for full testing. The accuracy of the different methods was verified by comparative tests.     

Comparison of isothermal and dynamic methods for the determinationof activation energy by thermogravimetry

Several dynamic methods for estimating activation energies have been developed. This development has arisen largely as a matter of convenience and the desire to minimize analysis time. While these methods generally afford values which are somewhat similar, the agreement among values from various methods is never outstanding. Further, the values obtained are often, at best, only approximations of the values obtained by the traditional isothermal approach. To better ascertain the utility of dynamic methods for the determination of activation energies, the activation energy for the thermal degradation of a standard vinylidene chloride/methyl acrylate (five-mole percent) copolymer has been generated by a variety of methods. The degradation of this polymer is an ideal reaction for evaluation of the various methods. At modest temperatures (<200°C), the only reaction that contributes to mass loss is the first order evolution of hydrogen chloride, i.e., there is only one significant reaction occurring and it is not impacted by competing processes. The best values (most reproducible; best correspondence to values obtained by titrimetry and other methods) are those obtained by plotting the natural logarithm of rate constants obtained at various temperatures vs. the reciprocal of the Kelvin temperature. Various dynamic methods yield values which are less reproducible and which approximate these values to a greater or lesser degree. In no case is the agreement good.     

RNAA in metrology: A highly accurate (definitive) method

The idea of highly accurate (definitive) methods by radiochemical neutron activation analysis (RNAA) is presented and illustrated with several examples of methods worked out in this Laboratory over the past several years. Definitive methods by RNAA are constructed by combining reactor neutron activation with very selective and quantitative post-irradiation separation of the indicator radionuclide by column chromatography followed by γ-ray spectrometric measurement. All conditions for the determination of the individual element are optimized and uncertainties associated with every step of the analytical procedure are minimized. Even after the method has been thoroughly elaborated and validated through the analysis of appropriate certified reference materials (CRMs), the results obtained in each series of measurements are acknowledged as obtained by definitive method only when a series of previously formulated criteria is simultaneously fulfilled. The examples of definitive methods for the determination of cadmium, cobalt and molybdenum, respectively, in biological materials are presented. Each of these methods has detection limit of the order of ng g⁻¹ or better, and yields accurate and precise results. The expanded standard uncertainty is of the order of 2.6% for the case of single-element determination (Co) and 3.4-5.2% for the less favourable case (Mo) where there is necessity for simultaneous determination of uranium to correct for interference due to fission reaction. Definitive methods by RNAA may constitute an option or alternative with respect to ID-MS as methods of “guaranteed accuracy” being also a perspective solution in the case of monoisotopic elements, for which ID-MS cannot be used.     

Supramolecular interaction of transition metal complexes with albumins and DNA: Spectroscopic methods of estimation of binding parameters

Binding parameters of metal complexes with albumins and DNA since the middle of 1990s are considered and summarized. The most widespread spectroscopic methods of estimation of binding parameters are discussed – direct fluorescent methods, indirect fluorescent methods (by fluorescence quenching parameters), and ways of estimation of binding constants by other optical spectroscopic methods. The methods and approaches to calculations used for the determination of binding constants are discussed. The data on the already found binding constants and kinetic parameters is systematized.     

Bestimmung von stickstoff in refraktärmetallen—I molybdän und wolfram

This is a report on round-robin tests concerning the determination of nitrogen traces in molybdenum and tungsten, which were carried out by the refractory metals group of the chemistry section of the Gesellschaft Deutscher Metallhütten- und Bergleute. The following methods were used: classical and modified Kieldahl methods (in particular, a newly developed micro-Kjeldahl method), inert-gas fusion, vacuum fusion and ultrahigh-vacuum diffusion extraction. As the nitrogen values obtained by the first round-robin test exhibited considerable scatter, possible shortcomings of the various Kjeldahl methods, as well as the quantitative nitrogen recovery by the extraction methods, were carefully examined. The second round-robin test then gave the following results: the nitrogen content of the investigated molybdenum sheet was 2 ppm, the content of the tungsten sheet 0.5 ppm. Classical Kjeldahl methods are not applicable to the determination of nitrogen contents below 10 ppm. Frequently, detection limits of Kjeldahl methods range considerably above 10 ppm, mainly because of contamination by reagents and/or the laboratory atmosphere. The micro-Kjeldahl method and the hot-extraction and fusion-extraction methods are capable of determining nitrogen contents down to 1 ppm at best. The only method available for nitrogen determinations in metals at sub-ppm levels is by ultrahigh-vacuum diffusion extraction. The good agreement between the nitrogen values obtained for molybdenum by the micro-Kjeldahl method and by the various extraction methods is the most reliable proof of the quantitative nitrogen recovery by the extraction methods.     

Determination of uranium by neutron activation analysis using substoichiometric separation

Three analytical methods for uranium by neutron activation are described. The methods are based on the substoichiometric separation of barium or lanthanum, which are the fission products of uranium-235 by neutron irradiation. Uranium contents in high purity materials were determined by the methods, which were found to be useful for the determination of a trace amounts of uranium.