The challenge of microelectronics for analytical chemistry

Summary Major new tasks for Analytical Chemistry arising from the rapid development of microelectronics are presented, taking as an example silicon technology for the production of highly integrated memory devices. Referring to the various steps of production of such devices in MOS-technology, important analytical problems and their treatment are discussed. It will be shown that surface and interface analysis techniques have a particular significance.     

Advanced ceramics and their basic products: A challenge to the analytical sciences

The analytical characterization required in the development and in the quality control of new ceramics is discussed. For the basic substances, the problems encountered in the development of routine techniques for a direct and reliable analysis of Al₂O₃, AlN, Si₃N₄, SiC, and ZrO₂ powders are reported. Among the atomic spectrometric methods, especially slurry atomization ICP-spectrometry is described. Also the problems encountered in the development of combined procedures as required for the characterization of reference samples are presented. Methods for the direct bulk analysis of ceramics and microdistributional analysis, as they are now under development with laser-based techniques and various probe techniques, are described as well.     

第49届分析科学暨光谱与其他谱学国际会议

本届国际会议于2003年6月1日～4日在加拿大Ottawa市召开,由该市Carleton大学主办。大会报告有2个:(1)加拿大Windsor大学RFAroca,表面增强共振拉曼与单分子谱图,获Herzberg奖;(2)加拿大Ionalytics公司RGuevre mont,高场不对称波形离子迁移谱(FAIMS)的发展,获Barringer研究奖。专题研讨会共16个。(1)感耦等离子体质谱联用技术的多用途性及其新方向;(2)毛细管电泳与其相关技术;(3)红外、拉曼与核磁共振谱;(4)水溶液的振动光谱;(5)人类健康和环境中的金属;(6)光谱学与医学的机遇-由崇高至荒诞;(7)以激光为基础的分析技术———激光诱…     

Carbon nanotubes and graphene in analytical sciences

Nanosized carbon materials are offering great opportunities in various areas of nanotechnology. Carbon nanotubes and graphene, due to their unique mechanical, electronic, chemical, optical and electrochemical properties, represent the most interesting building blocks in various applications where analytical chemistry is of special importance. The possibility of conjugating carbon nanomaterials with biomolecules has received particular attention with respect to the design of chemical sensors and biosensors. This review describes the trends in this field as reported in the last 6?years in (bio)analytical chemistry in general, and in biosensing in particular.

Principles of analytical calibration/quantification for the separation sciences

Calibration is an operation whose main objective is to know the metrological status of a measurement system. Nevertheless, in analytical sciences, calibration has special connotations since it is the basis to do the quantification of the amount of one or more components (analytes) in a sample, or to obtain the value of one or more analytical parameters related with that quantity. Regarding this subject, the aim of analytical calibration is to find an empiric relationship, called measurement function, which permits subsequently to calculate the values of the amount (x-variable) of a substance in a sample, from the measured values on it of an analytical signal (y-variable). In this paper, the metrological bases of analytical calibration and quantification are established and, the different work schemes and calibration methodologies, which can be applied depending on the characteristic of the sample (analyte+matrix) to analyse, are distinguished and discussed. Likewise, the different terms and related names are clarified. A special attention has been paid to those analytical methods which use separation techniques, in relation with its effect on calibration operations and later analytical quantification.     

Overview of the methodology of nuclear analytical techniques for speciation studies of trace elements in the biological and environmental sciences

Recent achievements in speciation studies of trace elements in the biological and environmental sciences by nuclear analytical techniques, mainly molecular activation analysis, position-sensitive spectrometry with a variety of exciting sources, and synchronous radiation-based analytical techniques (although radioisotope or enriched stable isotope-based speciation techniques are also used), particularly in our laboratory, are outlined. In this paper the merits and drawbacks of the nuclear analytical techniques are discussed, as are reagent blanks, contamination, and artifacts.     

Russian doctors of sciences working in analytical chemistry

Statistical data on Doctors of Sciences in Russian analytical chemistry are given.     

The role of analytical chemistry in environmental protection

Summary A review is given on the role of analytical chemistry in environmental protection. Particular emphasis is laid on the mutual interaction: Suitable analytical methods permit an appropriate assessment of the pollution and this makes possible regulations for its prevention or diminution. The necessary control in turn promotes the further development of analytical methods.The following points are discussed: Problems and effects of pollution, control systems, requirements of analytical work, trends in the development of methods. Finally, a survey of selected methods is given.

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Die Rolle der analytischen Chemie im Umweltschutz

Zusammenfassung Eine Übersicht über die Bedeutung der analytischen Chemie im Umweltschutz wird gegeben. Besonders wird die gegenseitige Wechselwirkung betont: Geeignete analytische Methoden gestatten eine bessere Beurteilung der Verschmutzung und ermöglichen dadurch, diese durch entsprechende Maßnahmen zu verhindern oder zu verringern. Die erforderliche Kontrolle führt wiederum zur Weiterentwicklung der Analytik.Nachfolgende Themen werden diskutiert: Problematik und Bedeutung der Umweltverschmutzung, Kontrollsysteme, Anforderungen an die analytischen Methoden, Trends der Entwicklung. Schließlich wird ein Überblick über einige ausgewählte Verfahren gegeben.

Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria.     

Singlet oxygen in the environmental sciences

This review of the part played by the singlet states of molecular oxygen in the environment deals with atmospheric aspects. There are five bound excited states of molecular oxygen that correlate with two ground state, ³P, oxygen atoms. Of these, three are singlets, although the other two states (triplets) are closely associated with singlet oxygen processes, especially in the mesosphere. A weakly bound quintet state has been invoked, as well, in explaining some aspects of the physical chemistry of the singlet species. Of the three singlet states, the a¹Δ_g is the most familiar. It has a low excitation energy, a long radiative lifetime, and is rather resistant to collisional deactivation in the gas phase. As a consequence, its chemistry has been susceptible to detailed study in the laboratory. These investigations, coupled with estimates of production rates, suggest that O₂(a¹Δ_g) is probably not important in initiating much chemical change in the lower atmosphere, at least in the gas phase; excited molecules dissolved in water droplets may promote chemical change under special circumstances. In the stratosphere and mesosphere, each of the bound excited states gives rise to characteristic emission features of the airglow, both by day and by night. The observational data, obtained from the ground, and from balloons, high-flying aircraft, rockets and satellites is surveyed as a background to examining the chemical and photochemical mechanisms by which the different states become excited. These mechanisms clearly differ by day and by night, and they also depend on the altitude from which the emission comes. The most intense feature of the oxygen dayglow, the Infrared Atmospheric Band, comes from O₂(a¹Δ_g) that is produced in the photolysis of ozone. Because dayglow measurements are sometimes used to derive ozone concentrations and altitude profiles in the atmosphere, the efficiency of production of the species in the photolysis of ozone is examined critically, and some unexpected laboratory findings are reported. The b¹Σ⁺ _g state of oxygen is excited during the day largely by resonance scattering, although some is also populated by energy transfer from O(¹D) to O₂. At night, recombination of O(³P) atoms is the most likely source of excitation of all the states of oxygen. Laboratory experiments that bear on these processes are reviewed, and theoretical estimates of the partitioning of recombination events between the different states are presented. Direct recombination into the a¹Δ_g and b¹Σ⁺ _g states is unlikely to be efficient enough to produce the observed concentrations of these species, and some indirect process is thus implicated. Laser excitation experiments show that quenching of the three higher excited (ungerade) states of oxygen by O₂ and, especially, N₂, can generate O₂(b¹Σ⁺ _g) with high efficiency; similar experiments demonstrate explicitly that the quenching of O₂(b¹Σ⁺ _g) by the atmospheric gases yields O₂(a¹Δ_g). A consistent excitation scheme for the nightglow emissions is presented; this scheme also pays attention to the “auroral green” line produced by the ¹S state of atomic oxygen, the intensities of which in the atmospheres of Earth and Venus provide some clues about the excitation of the molecular states. Finally, the laboratory studies are shown to indicate that the formation of excited molecular oxygen from vibrationally rich hydroxyl (OH) radicals is unlikely to be of major importance in the atmosphere.     

Advanced green analytical chemistry for environmental pesticide detection

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Immunoassays in environmental analytical chemistry

A review is presented which summarizes the recent developments of immunoassays in environmental analytical chemistry. The basic principle of the method and the following steps in the development of an immunoassay procedure are discussed in detail: Synthesis of the immunogen, immunization procedure, synthesis of the labelled antigen (tracer), advantages and drawbacks of radioimmunoassay, fluoroimmunoassay and enzyme immunoassay. A special emphasis is put on approved methods which can be applied in almost any analytical laboratory. Numerous examples of immunoassays for different pesticides and pollutants (dioxins, polychlorinated biphenyls, mycotoxins) are presented. Besides the respective test features, their applicability for residue determinations in biological samples is kept in the foreground. The advantages and drawbacks of the immunoassays are discussed in comparison with conventional analytical methods. An outlook to future application fields for immunoassays and new trends (e.g. the utilization of monoclonal antibodies) is presented.