Standardization, quality control and education in analytical chemistry

Quality matters have always been an intrinsic component of any curriculum in analytical chemistry. The realizations in the past have shown a wide variability in different countries. With the on-going internationalization of trade this is not a satisfactory situation as the goal of a measurement science supporting this globalization must encompass compatible measurement systems. In order to meet these requirements as soon as possible, and not just with future generations of yet-to-be-trained college graduates, a vigorous program of postgraduate education in analytical quality assurance is necessary in all countries, many of which have already recognized this need and introduced special courses dealing with these topics.This contribution presents a compilation of the most important current developments in analytical quality assurance as these also define the most urgent needs to reshape the educational process for graduates and post-graduates alike. Quantitative concepts are emphasized and the correlations between them are highlighted. Suggestions for topics to be covered in a 4-day post-graduate course on analytical quality assurance are given, based on more than five years of experience.Dedicated to my mother, Dr. med. univ. Gerda Wegscheider, on the occasion of her 70th birthday     

A review of opportunities for electrospun nanofibers in analytical chemistry

Challenges associated with analyte and matrix complexities and the ever increasing pressure from all sectors of industry for alternative analytical devices, have necessitated the development and application of new materials in analytical chemistry. To date, nanomaterials have emerged as having excellent properties for analytical chemistry applications mainly due to their large surface area to volume ratio and the availability of a wide variety of chemical and morphological modification methods. Of the available nanofibrous material fabrication methods, electrospinning has emerged as the most versatile. It is the aim of this contribution to highlight some of the recent developments that harness the great potential shown by electrospun nanofibers for application in analytical chemistry. The review discusses the use of electrospun nanofibers as a platform for low resolution separation or as a chromatographic sorbent bed for high resolution separation. It concludes by discussing the applications of electrospun nanofibers in detection systems with a specific focus on the development of simple electrospun nanofiber based colorimetric probes.     

Acoustically levitated droplets — a new tool for micro and trace analysis

First experiences with the technique of acoustical levitation of droplets in the field of analytical and atmospheric chemistry are reported. Acoustical levitation enables the contactless handling of solid and liquid microsamples. This avoids adsorption of analyte at and desorption of contaminants from container walls especially for liquid samples. Common experiments of sample preparation procedures were conducted in levitated drops like liquid/liquid extractions, solvent exchange, and analyte enrichment by evaporation of the solvent. A first approach was made to use acoustical levitation for the simulation of atmospheric chemistry situations. Dedicated to Professor Dr. K. B?chmann on the occasion of his 60th birthday on leave to GKSS-Forschungszentrum, Max-Planck-Strasse, D-21502 Geesthacht, Germany     

A new data management concept for AES and SAM

The problem of interchangeability of surface analytical data is gaining increasing importance in multi-method surface analysis. There are various surface analytical instruments in different laboratories on several automation levels. For these instruments, which are controlled by computer systems working with company-specific software under various operating systems, a standardised data format is necessary to allow an exchange of data. Therefore, we are developing a software package for the transfer, archiving and editing of surface analytical data called MAXMIND (management and exchange of method independent data), which is based on public domain software products. It allows the storage of all available and necessary information on experimental conditions and all parameters specific for a number of analytical techniques such as AES, SAM, XPS, SIMS, STM and AFM. Additionally, all data concerning the sample-preparation and the state of the instrument are included in order to allow a well-founded evaluation of the data and improved reproducibility of the experiment. This concept is demonstrated in detail for the two Auger techniques AES (Auger Electron Spectroscopy) and SAM (Scanning Auger Microscopy).Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday     

Modern Analysis

The important advances being made in modern analytical methods are indicative of the fundamental changes that are occuring in the theory and practice of “analytical chemistry”. “Information optimization” demands a new approach in teaching and research, and calls for the intergration of chemistry with other scientific and technical disciplines.     

Photoacoustic spectroscopy for process analysis

Photoacoustic spectroscopy (PAS) is based on the absorption of electromagnetic radiation by analyte molecules. The absorbed energy is measured by detecting pressure fluctuations in the form of sound waves or shock pulses. In contrast to conventional absorption spectroscopy (such as UV/Vis spectroscopy), PAS allows the determination of absorption coefficients over several orders of magnitude, even in opaque and strongly scattering samples. Small absorption coefficients, such as those encountered during trace gas monitoring, can be detected with cells with relatively short pathlengths. Furthermore, PA techniques allow absorption spectra of solid samples (including powders, chips or large objects) to be determined, and they permit depth profiling of layered systems. These features mean that PAS can be used for on-line monitoring in technical processes without the need for sample preparation and to perform depth-resolved characterization of industrial products. This article gives an overview on PA excitation and detection schemes employed in analytical chemistry, and reviews applications of PAS in process analytical technology and characterization of industrial products.     

Targeted Metabolomics for Biomarker Discovery

Metabolomics is a truly interdisciplinary field of science, which combines analytical chemistry, platform technology, mass spectrometry, and NMR spectroscopy with sophisticated data analysis. Applied to biomarker discovery, it includes aspects of pathobiochemistry, systems biology/medicine, and molecular diagnostics and requires bioinformatics and multivariate statistics. While successfully established in the screening of inborn errors in neonates, metabolomics is now widely used in the characterization and diagnostic research of an ever increasing number of diseases. In this Review we highlight important technical prerequisites as well as recent developments in metabolomics and metabolomics data analysis with special emphasis on their utility in biomarker identification and qualification, as well as targeted metabolomics by employing high‐throughput mass spectrometry.     

Determination of linear alkylbenzenesulfonates by high-performance liquid chromatography and capillary zone electrophoresis

High-performance liquid chromatography and capillary zone electrophoresis have been used for the separation of homologues and structural isomers of linear alkylbenzenesulfonates with subsequent UV detection. The analytical advantages of these techniques are applied to the analysis of technical products containing high amounts of LAS as well as river water samples with very low LAS concentrations using preconcentration steps.Dedicated to Professor Dr. H. Kriegsmann on the occasion of his 70th birthday     

Miniaturizing sample spots for matrix-assisted laser desorption/ionization mass spectrometry

The trend of miniaturization in bioanalytical chemistry is shifting from technical development to practical application. In matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), progress in miniaturizing sample spots has been driven by the needs to increase sensitivity and speed, to interface with other analytical microtechnologies, and to develop miniaturized instrumentation.We review recent developments in miniaturizing sample spots for MALDI-MS. We cover both target modification and microdispensing technologies, and we emphasize the benefits with respect to sensitivity, throughput and automation.We hope that this review will encourage further method development and application of miniaturized sample spots for MALDI-MS, so as to expand applications in analytical chemistry, protein science and molecular biology.     

Polyvinylpyrrolidon. Ein Tausendsassa in der Chemie

Exactly 70 years ago, PVP was invented by Prof. Dr. Walter Reppe at BASF and registered as a patent. Polyvinylpyrrolidone was initially used as a blood plasma substitute in the Second World War. Afterwards, little by little, it started being utilized in a multiplicity of sectors: pharmaceutical, cosmetic and detergent industries. PVP is now being used in more than one hundred different technical applications such as membranes, glue sticks, hot‐melt adhesives, hydrogels and for crop protection. Due to its versatile features such as water solubility, film and complex formation, adhesive and bonding power as well as due to its toxicological harmlessness, PVP is one of the most interesting technical specialty polymers in the field of chemistry.     

Modern analytical chemistry education in Europe at university level

Stimulated by the rapid growth of analytical chemistry in research and development, a discussion on the past, present and future role of analytical chemistry as part of the chemistry curricula at European universities is presented in this article. The present status of analytical chemistry curricula is described, based on a recent investigation of the Working Party on Analytical Chemistry (WPAC) of the Federation of European Chemical Societies (FECS) at 229 European universities. The evaluation of the questionnaires has been done for all institutions together, as well as for the 119 institutions with a separate chair or department of analytical chemistry and the 110 institutions without such a separate chair. The distribution of teaching hours between the classical and modern fields is generally significantly better and more flexible to new developments (like chemometrics, environmental and material sciences) at institutions with an own chair of analytical chemistry. This survey is also a key to earlier reviews on education in analytical chemistry stimulated and published by WPAC-members.     

From organometallic and polymer chemistry to applied materials science: transition metal catalyzed synthesis of polyolefins and polyolefin-based high-performance materials

A brief history of the development of transition metal-catalyzed olefin polymerization including the present status of polyolefin chemistry is given. The entire evolution of polyolefin chemistry will be outlined, giving ample attention to the development in the catalytic systems. Starting with the first generation PP catalysts (TiCl₃/AlClEt₂), the success story of organometallic chemistry, which resulted in modern supported and unsupported single site systems and finally functional group-tolerant group VIII systems will be summarized. Where applicable, examples of technical application will be given. Additionally, organometallic chemistry responsible for selectivity but also for termination reactions as well as the various “living” systems and the adherent implications for materials science will be discussed. Finally, the impact of related transition metal-catalyzed metathesis chemistry on the area of specialty materials will be outlined.     

Green analytical chemistry in sample preparation for determination of trace organic pollutants

The principles of green chemistry are applied to not only chemical engineering and synthesis, but also increasingly analytical chemistry. We describe environment-friendly analytical techniques applied to isolate and to enrich trace organic pollutants from solid and aqueous samples. Amounts of organic solvents used in analytical laboratories are reduced by applying solventless extraction, extraction using other types of solvent, assisted solvent extraction and miniaturized analytical systems.     

Shaping and exploring the micro- and nanoworld using bipolar electrochemistry

Bipolar electrochemistry is a technique with a rather young history in the field of analytical chemistry. Being based on the polarization of a conducting object which is exposed to an external electric field, it allowed recently the development of new methods for controlled surface modification at the micro- and nanoscale and very original analytical applications. Using bipolar electrodes, analyte separation and detection becomes possible based on miniaturized systems. Moreover, the modified objects that can be created with bipolar electrochemistry could find applications as key components for detection systems. In this contribution, the principles of bipolar electrochemistry will be reviewed, as well as recent developments that focus on the modification of objects at the nano- and microscale and their potential application in miniaturized analytical systems.     

Analytik in der Aufgabe praktischer Umwelt-Politikberatung

Ohne Zusammenfassung

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The role of analytical chemistry in practical environmental politics

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Herrn Prof. Dr. G. Tölg zum 60. Geburtstag gewidmet     

The significance of quantity and quality in the analytical literature

Summary Based on the faculty of recognition, awareness in the field of analytical chemistry and its influence on subsequent judgements are discussed, as well as the way in which the analyst relates to the analytical literature. The implication of quantity (or volume) in analytical literature is a minor problem. It is easily explained by the increasing number of contributing analysts, their improved working conditions and by the wider coverage given to the subject. The criteria of quality have become increasingly complex as a result of changes in the applications of analysis. In addition to technical subjects they now incorporate social (i.e. educational, medical, nutritional, environmental, ecological), terrestrial and even cosmic features.     

HOA (Heaviside Operational Ansatz) revisited: recent remarks on novel exact solution methodologies in wavefunction analysis

A viable methodology for the exact analytical solution of the multiparticle Schrodinger and Dirac equations has long been considered a holy grail of theoretical chemistry. Since a benchmark work by Torres-Vega and Frederick in the 1990s, the QPSR (Quantum Phase Space Representation) has been explored as an alternate method for solving various physical systems. Recently, the present author has developed an exact analytical symbolic solution scheme for broad classes of differential equations utilizing the HOA (Heaviside Operational Ansatz). An application of the scheme to chemical systems was initially presented in Journal of Mathematical Chemistry (Toward chemical applications of Heaviside Operational Ansatz: exact solution of radial Schrodinger equation for nonrelativistic N-particle system with pairwise 1/r(I) radial potential in quantum phase space. Journal of Mathematical Chemistry, 2009; 45(1):129–140). It is believed that the coupling of HOA with QPSR represents not only a fundamental breakthrough in theoretical physical chemistry, but it is promising as a basis for exact solution algorithms that would have tremendous impact on the capabilities of computational chemistry/physics. The novel methods allow the exact determination of the momentum [and configuration] space wavefunction from the QPSR wavefunction by way of a Fourier transform. In this note some remarks, examples and further directions, concerning HOA as a tool to solve and provide analytical insight into solutions of dynamical systems occurring in, but not limited to Mathematical Chemistry, are also posited.     

Analysis of Low Molecular Weight Homologues of Fiber-Forming Polycondensates

Oligomers belong to the gray area between low molecular weight chemistry and macromolecular chemistry. Although they represent an undesirable “natural impurity” in fiber-forming polycondensates, they serve as useful model compounds for the corresponding polymers in fundamental research. Whereas for many years new classes of oligomers were being made preparatively accessible and the isolation of higher oligomers in pure form was being pursued, at the present time the emphasis is on analysis. By a combination of classical chemical and instrumental methods of analysis from polymer and organic chemistry, the identification of oligomers of unknown structure, the analytical control of their synthesis and the determination of their content in technical polymers has meanwhile become a routine task.     

Analytical Chemistry in Modern Society: What we can Expect

Analytical chemistry today contributes many analytical techniques which are required in industry, environmental control, medical laboratories and other areas of society. However, increased portability and miniaturization has the potential to enable us to solve new problems such as the analysis of new matrices including the possibility to analyse even cellular compartments. In this development process it is also being attempted to produce instruments and techniques which can be used by non-specialists. The integration, in a recent future, of microanalytical systems into our water taps permitting to control the presence of contaminants or microanalytical systems to control our health profile are some examples of the future contribution of analytical chemistry to society which probably will change our life.     

Metrology in laboratory medicine – A necessity

 In a recent Letter to the Editor, Dr. B. Neidhart questioned the need to make clinical chemical measurement results traceable to international standards and to incorporate the principles of analytical quality assurance into clinical chemistry. An analysis of the arguments presented shows that modern laboratory medicine has to deliver accurate results, which are comparable over space and time, in order to improve the accuracy of diagnostic tools and minimize cost. The means to achieve accuracy and comparability are metrological traceability and quality assurance as supported by many national and international initiatives.