The scientific legacy of Howard Vincent Malmstadt

Howard Malmstadt was a true giant of Analytical Chemistry and clearly one of the most influential analytical chemists of the last 50 years. Howard, through his own work and that of his students (first generation) and their students (second generation) and their students' students (third generation) changed the course of Analytical Chemistry. His research interests were broad and ranged from analytical solution chemistry (titrimetry and reaction rates) and electrochemistry to atomic and molecular spectroscopy, chemical instrumentation, clinical chemistry and automation. Howard was also one of the most innovative and influential educators of our time. He changed forever the analytical curriculum through his many books on Electronics for Scientists, most written in conjunction with Chris Enke and Stan Crouch. Their texts and short courses went from pioneering the application of tube-based analog electronics (servo systems and operational amplifiers) in scientific measurements to the impact that integrated circuits and digital electronics would have on laboratory measurements. He strongly believed in the importance of “hands-on” in education. To this end, he expended considerable personal effort and time to see not only the development and commercialization of an effective laboratory infrastructure to support education in analog and digital electronics, but also oversaw the development of modular instrumentation for spectroscopy. Over the years he received many awards from the Analytical Chemistry community for his outstanding efforts and contributions to teaching and research. Many of Howard's students went on into academia. They and their students now represent the ongoing legacy for analytical chemistry that evolved from Howard's laboratory at Illinois. A remarkable diversity of research programs are underway in their laboratories. Topics range from atomic, laser, mass, and Raman spectroscopy to detection technology, analytical education, micro-fabricated instrumentation, and intercellular analytical measurements.     

Alexander Crum Brown and his Doctoral Thesis of 1861

Abstract

Organic chemistry began at the universities in the Habsburg Empire about 1840, when Josef Redtenbacher, a post-graduate student of Liebig in Giessen, established the first organic laboratory at Charles University, Prague. Following Liebig's teaching methods, he required laboratory work from his students. Redtenbacher's students then headed the new chemistry departments, which were established after the revolution of 1848. Several of Redtenbacher's students had also been trained as botanists and they focussed their research on phytochemical questions. Austrian chemists also contributed to theoretical organic chemistry. In 1853 Rochleder published a paper in which the quadrivalence of carbon was assumed. A more important contribution was made by Josef Loschmidt in 1861, when he published the graphical formulae of several hundred compounds. In contrast to the ideas of Gerhardt and Kekulé, Loschmidt assumed that the constitution of a compound can be deducted from its reactions. Loschmidt's work attracted little interest abroad and was only rediscovered many years later by Richard Anschütz.     

Quality assurance systems in research and routine analytical laboratories

In our article we explain the connections between the implementation of quality assurance (QA) in research and routine analytical laboratories. J. K. Taylor claims that QA in an analytical laboratory consists of two independent but closely related terms, quality control and quality assessment. If we construct the QA system according to his ideas, problems concerning quality can be solved with only one concept regardless of the type of analytical laboratory. Therefore there is no need to introduce new QA standards for research laboratories as suggested in some papers. In the routine laboratory quality control is more important, while in the research laboratory quality assessment is dominant.     

Quality assurance systems in research and routine analytical laboratories

 In our article we explain the connections between the implementation of quality assurance (QA) in research and routine analytical laboratories. J. K. Taylor claims that QA in an analytical laboratory consists of two independent but closely related terms, quality control and quality assessment. If we construct the QA system according to his ideas, problems concerning quality can be solved with only one concept regardless of the type of analytical laboratory. Therefore there is no need to introduce new QA standards for research laboratories as suggested in some papers. In the routine laboratory quality control is more important, while in the research laboratory quality assessment is dominant.

     

Interpretation of analytical chemical information by pattern recognition methods-a survey

Since the late sixties, pattern recognition techniques have been used by analytical chemists to facilitate the interpretation of multivariate analytical information. Most research within the field has focused on adapting pattern recognition methods to chemical data. This has been necessary since chemical data are often complicated by the fact that distributions are unknown. Through the first decade of chemical pattern recognition, promising results have been obtained even though the data sets studied have frequently been rather small for statistical analysis. The past few years have shown that an increasing number of analytical chemists are interested in the sheer utility of pattern recognition. This can be taken as a valid sign of a useful approach. The present communication surveys this development. Those methods which have proved most useful for analytical chemical data are described in some detail, and applications within the various fields of analytical chemistry are reviewed.     

Quality assurance in the view of a commercial analytical laboratory

 The necessity for analytical quality assurance is primarily a feature of the analytical process itself. With the full establishment of the EU domestic market, it is also becoming a legal necessity for an increasing number of analytical laboratories. The requirements which laboratories will need to fulfil are stipulated in DIN EN 45 001. Accredited testing laboratories must in fact provide evidence that they work solely in accordance with this standard. National and EU commissions, which are legislative authorities, tend therefore to specify analytical methods, e.g. in the form of regulations or appendices thereto, intended to ensure that results from different laboratories will be comparable and hence will stand up in a court of law. The analytical quality assurance system (AQS), introduced by the Baden-Württemberg Ministry for the Environment in 1984, obliges laboratories to regularly participate in collaborative studies and thereby demonstrate their ability to provide suitably accurate analyses. This alone, however, does not sufficiently demonstrate the competence of a laboratory. Only personal appraisal of the laboratory by an auditor, together with the successful analysis of a sample provided by the same and performed under his observation, can provide proof of the competence of the laboratory. From an analytical point of view, the competence of a laboratory must be regarded as the decisive factor. Competence can only be attained through analytical quality assurance, which thus must be demanded of all laboratories. Received: 4 October 1996 Accepted: 15 January 1997     

PDMS微流体系统的加工制作

目前,微流体装置越来越多地应用到分析系统、生物医学、化学等基础研究领域。传统的微流体系统制作方法是对玻璃和硅片进行刻蚀。用软刻法制作PDMS(Poly(dimethylsiloxane)：聚二甲基硅氧烷)微流体装置比传统的制作方法更快速,成本更低廉,并且对于通道的密封也不需要玻璃或硅芯片键合密封等复杂工艺。这类软刻法的核心技术是快速原样制作法和复制压模技术。相对于微电子加工工艺,软刻法制作过程不需要超静环境,化学家和生物学家可在普通的实验室实现加工制作。本文介绍了PDMS微装置在分离和生物材料模式化等方面的应用。     

Analytical Chemistry — today''s definition and interpretation

Conclusion Since every science is defined as a way of knowledge accumulation and theory formulation, the magnificent cognitive power of Analytical Chemistry cannot be disregarded by any natural scientist. Therefore the state of the art in the field of Analytical Chemistry has a strong impact on other scientific disciplines. Without the cognitive feedback of analysis, no synthesis, no high-tech process, or pollution control actions are possible. Since the whole perception of the properties and laws of the material world are so strongly dependent on the level of performance of Analytical Chemistry it has become a self-reliant, chemical subdiscipline. Analytical Chemistry also includes a tremendous economic side, directly through the market for analytical instruments and, above all, indirectly through decisions taken in industry and the society as a whole based on analytical results. Because nearly a third of all chemists work in the field of Analytical Chemistry, it should be taught at a sufficient level at every University which has a Chemistry Department, in order to ensure the continued knowledge base which this subdiscipline uniquely provides.     

Gene silencing by double-stranded RNA (Nobel Lecture)

I would like to thank the Nobel Assembly of the Karolinska Institute for the opportunity to describe some recent work on RNA‐triggered gene silencing. First a few disclaimers, however. Telling the full story of gene silencing would be a mammoth enterprise that would take me many years to write and would take you well into the night to read. So we'll need to abbreviate the story more than a little. Second (and as you will see) we are only in the dawn of our knowledge; so consider the following to be primer …? the best we could do as of December 8th 2006. And third, please understand that the story that I am telling represents the work of several generations of biologists, chemists, and many shades in between. I'm pleased and proud that work from my laboratory has contributed to the field, and that this has led to my being chosen as one of the messengers to relay the story in this forum. At the same time, I hope that there will be no confusion of equating our modest contributions with those of the much grander RNAi enterprise.     

Recent Advances of Polymer Monolithic Columns Functionalized with Micro/Nanomaterials: Synthesis and Application

The field of separation science has recently witnessed an explosion of interest and progress in the design and study of porous polymer monolithic materials. Monolithic columns with their unique structure possess some exceptional characteristics, which make them an excellent tool in the hands of analytical chemists, not only for separation but also for sample pretreatment. As a new member of the polymer monolith family, the micro/nanomaterial-functionalized polymer monolith has attracted considerable attention due to its many distinct characteristics, such as high permeability and selectively tailored surface chemistries. It exhibits great potential in separation science and analytical sample preparation. This review summarizes and highlights recent major advances of the micro/nanomaterial-functionalized polymer monolith, focusing on design considerations and the application of separation and enrichment. A brief overview of the properties of polymer monolithic columns is included, and then specific attention is paid to discuss the methods of fabrication and application of the micro/nanomaterial-functionalized polymer monolith in separation, sample pretreatment and enrichment, and highly sensitive detection. Finally, future possible research directions and challenges in the field are discussed.     

Sample preparation for chromatography: an African perspective

Africa as a continent has its unique challenges for analytical chemists in sample preparation for chromatographic analyses. The areas of agriculture, environment, food and health provide formidable challenges when it comes to method development, for example, drought can result in inadequate supplies of good quality water. The testing of water quality necessitates the development of assay methods that can be employed to not only determine the quantities of pesticides associated with malaria and tsetse fly eradication programmes, but also to monitor mycotoxins or neurotoxins. Urbanisation has also meant that endocrine disruptors such as phthalate esters need to be monitored. This review will profile some of the activities by analytical chemists practising in the African continent, who seek to address some of the challenges in sample preparation for chromatographic analyses.     

Immunochemical applications in environmental science

Immunochemical methods are based on selective antibodies combining with a particular target analyte or analyte group. The specific binding between antibody and analyte can be used to detect environmental contaminants in a variety of sample matrixes. Immunoassay methods provide cost-effective, sensitive, and selective analyses for many compounds of environmental and human health concern. Immunoaffinity chromatography methods have been integrated with chromatographic methods and are also being used as efficient sample preparations prior to immunochemical or instrumental detection. Immunosensors show promise in obtaining rapid online analyses. These and other advancements in immunochemical methods continue the expansion of their role from field screening methods to highly quantitative procedures that can be easily integrated into the environmental analytical laboratory.     

Ball milling in organic synthesis: solutions and challenges

During the last decade numerous protocols have been published using the method of ball milling for synthesis all over the field of organic chemistry. However, compared to other methods leaving their marks on the road to sustainable synthesis (e.g. microwave, ultrasound, ionic liquids) chemistry in ball mills is rather underrepresented in the knowledge of organic chemists. Especially, in the last three years the interest in this technique raised continuously, culminating in several high-quality synthetic procedures covering the whole range of organic synthesis. Thus, the present tutorial review will be focused on the highlights using this method of energy transfer and energy dissipation. The central aim is to motivate researchers to take notice of ball mills as chemical reactors, implementing this technique in everyday laboratory use and thus, pave the ground for future activities in this interdisciplinary field of research.     

Trends in lipase-catalyzed asymmetric access to enantiomerically pure/enriched compounds

Over the last few years, there has been a dramatic increase in the number of publications in the field of lipase-catalyzed reactions performed in common organic solvents, ionic liquids or even non-conventional solvents. A fairly large percentage of these publications have emerged from organic chemists who have recognized the potential of biocatalysis as a viable and popular technique in organic synthesis. Considerable research has shown that reactions catalyzed by enzymes are more selective and efficiently performed than many of their analogues in the organic chemistry laboratory. This review article focuses on some of the recent developments in the rapidly growing field of lipase-catalyzed asymmetric access to enantiomerically pure/enriched compounds. The literature search is dated back to the last five years and covers some comprehensive examples.     

Experience with in-house PT-schemes in the chemical industry

There are many different means of demonstrating the quality of performance of an analytical laboratory. Proficiency testing (PT) is just one! As in other analytical fields, interlaboratory comparisons play an important role in the chemical industry. Collaborative trials or method performance studies do have a long tradition in this field. Sometimes they were designed as laboratory performance studies with the clear aim of making analytical results comparable, e.g. petrol, coal, gas, noble metals analyses – not to mention the biggest PT scheme run on a daily world-wide basis – trade itself. All this is an ongoing process, which started long before the idea of assessing and accrediting the performance of analytical laboratories was born. However, when striving for accreditation in 1996, the analytical production laboratories of the Chemicals Business Unit of the Bayer AG in Germany implemented another facet of PT schemes. In-house-PT schemes are performed regularly and turned out to be useful in evaluating, monitoring, and thus improving, the quality of routine analytical work. Received: 5 December 2000 Accepted: 15 January 2001     

GRAFT COPOLYMERIZATION OF VINYL MONOMERS ONTO JUTE FIBERS

Abstract

Among the various types of copolymerization, graft copolym-erization has attracted considerable attention among applied polymer chemists. Graft copolymerization is a process of copolymerization of one kind of monomer in its polymeric state with another polymer which may be either synthetic or natural. So a graft copolymer is a high polymer whose molecule consists of two or more polymeric parts of different composition, chemically united together. Graft copolymerization onto textile fibers is a challenging field of research with unlimited future prospects [1-10]. This is attractive to chemists as a means of modifying macromolecules since, in general, degradation is minimized. The desirable properties of the polymer are retained, and copolymerization Drovides additional properties throuerh the added polymer.     

Quality criteria for residue analysis and reference materials. Relationship between legal procedures and materials

Summary For qualitative results objective reliability checks are often not present at all or applicable. Interlaboratory ring testing of methods, as sometimes required, showed often not to be applicable simply because enough adequate laboratories are not available. For instance this situation applied to the large number of methods of unclear reliability status, to be used for residue monitoring of hormonal growth promotors (anabolic agents), which are completely banned within the European Communities since January 1988. This impasse was circumvented in 1987 with the formulation by an international group of analytical experts of a set of quality criteria for common analytical techniques like TLC, GC and HPLC (separation), UV, MS and IR spectrometry (detection) and immunoassays (separation and detection). These criteria, now published, are overviewed, as well as the availability of the control and reference materials belonging to them for actual analytical quality control and for validation of laboratories. Although developed for anabolic agents this new approach is applicable in practice for nearly all organic analytes and since very recently also for heavy metals. This approach has clear consequences for the mandatory quality of legislative residue analyses of food stuffs. As based on, amongst others, the combined experience of regulatory residue chemists within the EC, a collection of experimental selectivity indices is presented to rank the required specificity of regulatory residue methods (ranging from within laboratory orientation to international forensic purposes) in an objective way. Finally an estimate is summarized of the financial consequences of the applicable analytical techniques.     

Software tools for green and sustainable chemistry

In this review, we consider green chemistry metrics, related software tools, and the opportunities and challenges for their use in research laboratories. We provide an overview of state-of-the-art software designed both to aid researchers in planning and conducting chemical experiments and to assess sustainability of individual reactions and synthetic routes. The increasing digitalisation of research means that there is great opportunity for more extensive use of computational tools by synthetic chemists and for closer integration of green chemistry principles into the routine work of chemical laboratories. We discuss the scope for using software tools in the laboratory and assisting synthetic chemists in the adoption of green and sustainable chemistry approaches that are suitable for their specific purposes.     

Sequential Transformations in Organic Chemistry: A Synthetic Strategy with a Future

Organic-chemical synthesis has always fascinated chemists and will not lose its importance in the future. It is a truism that all chemists—and others too—are dependent on the synthesis of those compounds with which they want to work. As a result, organic-chemical synthesis today is more than ever before the cutting edge of organic chemistry, biology, biochemistry, medicine, physics, and material science. Synthesis is also the basis of the chemical industry. For the passionate synthetic chemist, however, synthesis is much more than just a method for obtaining compounds; it is the expression of his creativity, intelligence, ability, and also his perseverance.     

Chemistry in Times of Artificial Intelligence

Chemists have to a large extent gained their knowledge by doing experiments and thus gather data. By putting various data together and then analyzing them, chemists have fostered their understanding of chemistry. Since the 1960s, computer methods have been developed to perform this process from data to information to knowledge. Simultaneously, methods were developed for assisting chemists in solving their fundamental questions such as the prediction of chemical, physical, or biological properties, the design of organic syntheses, and the elucidation of the structure of molecules. This eventually led to a discipline of its own: chemoinformatics. Chemoinformatics has found important applications in the fields of drug discovery, analytical chemistry, organic chemistry, agrichemical research, food science, regulatory science, material science, and process control. From its inception, chemoinformatics has utilized methods from artificial intelligence, an approach that has recently gained more momentum.