电化学分析的发展及应用

评述了从2001年1月-2002年12月间我国电化学分析发展的概况。内容分极谱与伏安法，微电极、超微电极和修饰电极，离子选择性电极与传感器，示波分析法，电泳及色谱电化学，光谱电化学、电致发光，扫描电化学显微镜及石英晶体微天平，化学计量学方法，电位分析及其它和仪器装置及实验技术等。引用文献591篇。     

原子荧光光谱进样技术的研究进展

原子荧光光谱已成为检测金属或类金属的重要手段,其仪器进样方式与所用原子化器类型直接相关。根据进样原理的不同,综述了原子荧光光谱仪器的直接进样、喷雾进样、化学蒸气发生进样和电热蒸发进样4种进样技术,详细介绍了原子荧光光谱各进样技术特别是化学蒸气发生进样和电热蒸发进样的发展历程、原理及优缺点,展望了原子荧光仪器进样技术的发展前景。引用文献75篇。     

农产品中重金属的检测方法研究进展

综述了农产品中重金属的检测方法如光谱分析法(包括原子吸收光谱法、电感耦合等离子体原子发射光谱法、原子荧光光谱法和X射线荧光光谱法)、色谱分析法、电化学分析法和快速检测方法(包括酶联免疫吸附法、生物传感器法、酶抑制法、试纸和试剂比色法)的研究进展,并对其发展前景进行了展望(引用文献83篇)。     

荧光分析法的近期发展

近10年来,由于微量分析的需要迅速增加,灵敏度高选择性强的荧光分析法日益受到重视。有关文献数量猛增,内容也从一般仪器及分析方法介绍发展到高精度、高灵敏度、自动化、多用途的新仪器新技术研究。荧光分析对象从以无机样品为主发展到以有机及生化样品为主,并从成分分析向化学结构、化学形式、微观分析、空间分布等状态分析发展,应用遍及各个领域。荧光光谱图册也陆续出版,美国费城Sadtler研究实验室自1974年起出版标准荧光光谱图及各专用荧光光谱图(如药物)。荧光分析法的应用范围与发射光谱法、火焰光度法、质谱法等相仿,成为一种重要的仪器分析方法。     

区分化学分析法与仪器分析法适用性的实践教学探索

根据方法原理,分析化学的常用分析方法可分为化学分析法和仪器分析法。高灵敏度、高选择性、高自动化、数字化和智能化已成为分析化学的发展方向,仪器分析法成为了分析化学发展的主流和热点。因此,在校本科生往往忽视化学分析法的重要作用以及适用范围,陷入仪器分析法为万能分析方法的误区。本文选用络合滴定法和原子吸收光谱法分别对常量含铅样品进行测试,通过考察测试结果的相对误差大小,探索了化学分析法和仪器分析法的适用范围,从而纠正了在校本科生的唯仪器分析法的错误观念。     

电化学分析的进展及应用

本文对2005年1月～2007年3月间我国电化学分析的发展进行了评述.文章按照电化学分析的不同领域分为极谱与伏安法,微电极、超微电极和修饰电极,离子选择性电极与传感器,示波分析法,电泳及色谱电化学,光谱电化学、电致发光法,石英晶体微天平,化学计量学方法,其他分析方法和仪器装置及实验技术等几部分.引用文献561篇.     

羟基的区别定量分析

从原理、可操作性、测定范围等方面论述了伯、仲、叔羟基的定量分析方法,并对化学动力学法、红外光谱法、紫外光谱法、极谱法和各种核磁法进行了综合比较。各种方法各有优势,宜根据实际条件进行选择,其中仪器分析法尤其是核磁法代表了羟基定量分析法的发展方向。     

水产养殖业使用抗生素造成的地表水污染及检测方法

介绍了水产养殖业使用抗生素对地表水的污染,分析了抗生素残留的危害,指出了我国水产养殖水域中抗生素分析的重要性及紧迫性。从检测分析角度,列举比较了国内外使用的主要抗生素分析方法,包括免疫分析法和化学仪器分析法两大类,阐明了我国近期对水产养殖水域抗生素研究的主要发展趋势。     

书刊征订

《现代近红外光谱分析技术》(第二版)新书出版近红外光谱是20世纪80年代中期才为人们所关注的一种新技术。该书系统地介绍了近红外光谱技术的概貌、近红外吸收光谱的基本原理、近红外光谱仪器、常用化学计量学方法及软件、定性与定量分析、在线过程分析技术,并重点介绍了该技术的最新进展和在石油化工领域的应用。该书可供从事分析化学、仪器分析、过程优化、化工和石油化工生产以及农业、食品、纺织、制药和环保等专业的广大科技工作者和大专院校有关师生阅读参考。《现代近红外光谱分析技术》由陆婉珍院士主编,中国石油化工出版社出版。欲…     

电化学分析

本文是《分析试验室》定期评述中电化学分析第六篇评述文章。它评述了从１９９７年１月至１９９８年１０月期间我国电化学分析的进展。内容分基础理论与应用研究两大部分。前者包括电化学分析理论研究、电分析化学中的化学计量学方法,后者包括极谱与伏安法,络合吸附波与催化波,线性扫描伏安法,示差脉冲伏安法,吸附溶出分析法,示波分析法,微电极、超微电极与化学修饰电极,离子选择电极与各类传感器,光谱电化学,扫描隧道显微法和液／液界面电化学分析,电化学检测／电泳、色谱技术,电化学免疫法,电位分析法及其它等。共引用文献４８３篇。     

Sample preparation and current applications of liquid chromatography for the determination of non-structural carbohydrates in plants

This article summarizes the current methods of determination of non-structural carbohydrates (NSCs) in plant samples based on liquid chromatography (LC). NSCs comprise several types of carbohydrates: sugar alcohols (e.g., sorbitol), monosaccharides (e.g., glucose and fructose), disaccharides (e.g., sucrose), oligosaccharides (e.g., raffinose) and polysaccharides [e.g., starch and polyfructans (e.g., inulin)]. NSCs are important in plant metabolism and have to be strictly distinguished from all sorts of structural carbohydrates (e.g., polysaccharide cellulose) that make up the backbone of the plants. Consequently, preservation of structural carbohydrates is a crucial step during sample preparation for NSC determination and is therefore addressed.Sugar alcohols, monosaccharides, disaccharides and those oligosaccharides that are easily soluble in polar solvents can be analyzed directly by high-performance LC. They are also referred to as free carbohydrates (FCs).However, polysaccharides are generally submitted to hydrolyzation into monomers prior to their quantitative analysis. This can be done either chemically, using acids, or enzymatically - both methods are discussed. For identification and quantification of the NSCs after LC separation, the following detectors are used: pulsed amperometry, refractive index, evaporate light scattering and finally, mass spectrometry.     

Inflation of correlation in the pursuit of drug-likeness

Drug-likeness is a frequently invoked, although not always precisely defined, concept in drug discovery. Opinions on drug-likeness are to a large extent shaped by the relationships that are observed between surrogate measures of drug-likeness (e.g. aqueous solubility; permeability; pharmacological promiscuity) and fundamental physicochemical properties (e.g. lipophilicity; molecular size). This article draws on examples from the literature to highlight approaches to data analysis that exaggerate trends in data and the term correlation inflation is introduced in the context of drug discovery. Averaging groups of data points prior to analysis is a common cause of correlation inflation and results from analysis of binned continuous data should always be treated with caution.     

Numerical solution of hydraulic models based on the axially-dispersed plug flow model by Laplace transforms

The problem of solving hydraulic models based on the axially-dispersed plug flow model which are applicable for the mathematical modelling of different flow-through systems both in chemical analysis (e.g., chromatography, flow injection analysis) and chemical industry (e.g., different tubular reactors) is discussed. Methods for numerical inversion of the model solution in the Laplace domain by expanding it into series of orthogonal functions are compared. Best results with respect to precision and consumption of computation time are given by the methods employing Chebyshov polynomials of the first kind and Fourier sine series. These methods were found to be better in these respects than some other frequently used numerical inversion methods.     

Digital simulation of the effect of dispatching rules on the performance of a routine laboratory for structural analysis

Several output characteristics of a laboratory for structural analysis are shown to be identical with the output of a model of that laboratory, e.g. the histograms of the input and output density (samples/day), the histograms of the number of samples present in the laboratory, the histograms of the delays and several cross-correlations. The effect of various strategies concerning priorities between various groups of samples is forecast, e.g. samples with a different expected analysis time, samples from various sources, samples with a different history in the laboratory. The effects of the introduction of an adaptable routing procedure, several technician assignment decisions and strategies on the termination of the analysis are simulated.     

GC-MS analytical methods for the determination of personal-care products in water matrices

This article discusses the more recent methods combining gas chromatography and mass spectrometry (GC-MS) for analysis of personal-care products (PCPs) in water matrices. We describe different procedures for sample extraction and preparation as well as different instrumental methods commonly used for these compounds. GC-MS and GC-tandem MS (GC-MS²), which are complementary to liquid chromatography combined with MS (LC-MS), allow identification and quantification of PCPs belonging to different classes with the sensitivity and the selectivity necessary for environmental monitoring. The compounds investigated include fragrances (e.g., nitro and polycyclic musks), antimicrobial compounds (e.g., triclosan), ultraviolet blockers (e.g., methylbenzylidene camphor), antioxidants and preservatives (e.g., phenols and p-hydroxybenzoic acid (parabens)) and insect repellents (e.g., N,N-diethyl-m-toluamide (DEET)). We critically review data in the literature by focusing attention on analytical methods devoted to simultaneous detection and quantification of structurally diverse pharmaceuticals and PCPs.     

Vibronic coupling in benzene cation and anion: vibronic coupling and frontier electron density in Jahn-Teller molecules

Vibronic coupling constants of Jahn-Teller molecules, benzene radical cation and anion, are computed as matrix elements of the electronic part of the vibronic coupling operator using the electronic wave functions calculated by generalized restricted Hartree-Fock and state-averaged complete active space self-consistent-field methods. The calculated vibronic coupling constants for benzene cation agree well with the experimental and theoretical values. Vibronic coupling density analysis, which illustrates the local properties of the coupling, is performed in order to explain the order of magnitude of the coupling constant from view of the electronic and vibrational structures. This analysis reveals that the couplings of the e2g2 and e2g3 modes in which the large displacements locate on C-C bonds are strong in the cation. On the other hand, they are greatly weakened in the anion because of the decrease of electron density in the region of the C-C bonds, which originates from the antibonding nature of the singly occupied molecular orbital of the anion. However, the difference of the electronic structure has a little influence on the vibronic coupling of the e2g4 mode. These results indicate that the vibronic coupling depends not only on the direction of the nuclear displacement but also on the frontier electron density.     

Life cycle assessment and sustainability analysis of products, materials and technologies. Toward a scientific framework for sustainability life cycle analysis

There are many approaches to study the environmental and sustainability aspects of production and consumption. Some of these reside at the level of concepts, e.g., industrial ecology, design for environment, and cleaner production. Other approaches are based on the use of quantitative models, e.g., life cycle assessment, material flow accounting and strategic environmental assessment. This paper focuses on the development of a framework that is able to incorporate different models for environmental analysis, with the option of a broader scope that also includes economic and social aspects, thus covering the three pillars of sustainability. This framework builds on the ISO-framework for life cycle assessment, but takes a broader view, and allows us to move from micro questions on specific products, via meso questions on life styles up to macro questions in which the entire societal structure is part of the analysis.     

Trace element speciation by ICP-MS in large biomolecules and its potential for proteomics

Latest studies on the chemical association of trace elements to large biomolecules and their importance on the bioinorganic and clinical fields are examined. The complexity of the speciation of metal-biomolecules associations in various biological fluids is stressed. Analytical strategies to tackle speciation analysis and the-state-of-the-art of the instrumentation employed for this purpose are critically reviewed. Hyphenated techniques based on coupling chromatographic separation techniques with ICP-MS detection are now established as the most realistic and potent analytical tools available for real-life speciation analysis. Therefore, the status and potential of metal and semimetals elemental speciation in large biocompounds using ICP-MS detection is mainly focused here by reviewing reported metallo-complexes separations using size-exclusion (SEC), ion-exchange (IE), reverse phase chromatography (RP) and capillary electrophoresis (CE). Species of interest include coordination complexes of metals with larger proteins (e.g. in serum, breat milk, etc.) and metallothioneins (e.g. in cytosols from animals and plants) as well as selenoproteins (e.g. in nutritional supplements), DNA-cisplatin adducts and metal/semimetal binding to carbohydrates. An effort is made to assess the potential of present trace elements speciation knowledge and techniques for "heteroatom-tagged" (via ICP-MS) proteomics.     

Simultaneous measurement of weight loss and delta temperature

Simultaneous TG (thermogravimetric analysis)-DTA (differential thermal analysis) measures both differential temperatures and weight changes in a material as a function of temperature or time in a controlled atmosphere. Simultaneous measurement of these two material properties not only improves productivity but also simplifies interpretation of the results. The complementary information obtained allows differentiation between endothermic and exothermic events which have no associated weight loss (e.g. melting and crystallization) and those which involve a weight loss (e.g. degradation). The combined evaluation also assures identical experimental and sampling conditions for both measurements, thereby eliminating those sources of uncertainty. This paper briefly describes a new simultaneous TG-DTA instrument with emphasis on how the measurements are made and with several typical applications     

Analysis of benzoxazinone derivatives in plant tissues and their degradation products in agricultural soils

Plant allelopathy may be considered an additional means of weed control in modern agriculture, but its means of action are not well understood and knowledge of specific allelochemicals involved in allelopathy is required.Benzoxazinoids are a chemical family with the most active allelopathic compounds in some crops (e.g., wheat, rye or maize). The analysis of these analytes has been based mainly on gas chromatography coupled to mass spectrometry (MS) and liquid chromatography (LC) coupled to ultraviolet detection. To improve the sensitivity and selectivity, new methodologies (e.g., LC coupled to MS and tandem MS) are being developed. Less information is available on the analytical strategies to determine their degradation products in soil samples.This article presents an overview of recent advanced analysis of benzoxazinone derivatives in plant tissues and their degradation products in agricultural soils.