Teaching Chemometrics with a Bioprocess: Analytical Methods Comparison Using Bivariate Linear Regression

We present an advanced analytical chemistry laboratory experiment involving chemometrics. Students perform a comparison of two analytical methods by checking several analyte concentrations within a certain range by using least-squares linear regression. They obtain statistical information such as the presence of constant and proportional biases. The exercise is based on the determination of glucose levels using two colorimetric methods (enzymatic and Somogyi—Nelson) in a very simple batch system formed by an infusion of tea, glucose, and a combination of a yeast (Schizosacaromyces pombe) and a bacteria (Acetobacter xylimun), usually named Kombucha. Several samples are collected during a week of laboratory work, and measurements are performed in a subsequent four-hour laboratory class. Although commercial computer software exists for a variety of statistical applications, specific programs for the application of statistics to analytical chemistry are not prevalent. In order to solve this particular problem, a Matlab 5.3 routine is presented.     

Analytical Chemistry in the System of Interrelationships among Disciplines Studied at Classical Universities

Interrelationships between a university course on analytical chemistry and other disciplines attended by students specializing in chemistry are discussed. The teaching of analytical chemistry at a level corresponding to the present state of the art requires optimizing the order of teaching of interdisciplinary courses and some changes in the curricula of these courses (especially, in physics). A consideration of interrelationships between disciplines also implies a modification of the course on analytical chemistry (to avoid doubling, etc.).     

Analytical chemical laboratory exercises on basic and advanced level at the Technical University Budapest

An overview on the practical laboratory work done by the chemical engineering students is given at different levels of the curriculum of the Faculty of Chemical Engineering. Laboratory exercises and individual laboratory work is carried out at the following levels: Basic level. The different analytical chemical methods are acquisited by the students. Advanced level. A problem oriented project work is done with integrated use of the different analytical methods in the 8th semester. Thesis work. Specialized individual work on an elected research topic. Postgraduate courses. Organized for the understanding and practice of the latest methods and applications in the analytical chemistry. The programs of the different levels are detailed in the following. Received: 10 January 1996 / Accepted: 20 May 1996     

Conceptual polymorphism of entropy into the history: extensions of the second law of thermodynamics towards statistical physics and chemistry during nineteenth–twentieth centuries

After the birth of thermodynamics’ second principle—outlined in Carnot's Réflexions sur la puissance motrice du feu (1824)—several studies provided new arguments in the field. Mainly, they concerned the thermodynamics’ first principle—including energy conceptualisation—, the analytical aspects of the heat propagation, the statistical aspects of the mechanical theory of heat. In other words, the second half of nineteenth century was marked by an intense interdisciplinary research activity between physics and chemistry: new disciplines applied to the heat developed in the form of analytical, mechanical and statistical theories. Inside all these theories, entropy—the brand-new function that Clausius coined in his Mechanical theory of heat—started to play a central epistemic role. In the present paper, we analyse some steps of the historical process of conceptualisation of such function from 1850 to 1902. Particularly, we retrace the historical–foundational path that—starting from Clausius’ Second Law—lead Boltzmann and Gibbs to their distinguished formulations of statistical entropy. As usual, our research has been unrolled through the analyses of primary sources and by leaning on critical readings of the secondary literature. As for the methodological approach, text analysis of historical documents constituted our privileged modus operandi. This paper is the expression of a collaborative historical research program focused on the thermodynamic foundations of physics–chemistry relationship; early results have already been published by the same authors upon the concepts of reversibility––and––thermal equilibrium.

     

Pedagogic Interest of the H2O2, Cu2+, SCN-, OH- Oscillating Reaction

Chemical reactivity is generally taught by considering the chemical properties of the reacting entities (acid-base, oxidation-reduction, complexation, and precipitation) and the values of the corresponding equilibrium thermodynamic constants (K_a, E⁰ K_d, K_s). This approach, however, is not well-suited to the dynamic chemical systems that are often encountered in industrial and environmental chemistry where nonequilibrium conditions prevail. In this respect, oscillating reactions are a good illustration of the limits of equilibrium thermodynamics and show the need for a complementary dynamic nonequilibrium study. We describe here an oscillating reaction that is easy to carry out in an inorganic chemistry practical class as it uses common reactants (H₂O₂, KSCN, CuSO₄, NaOH). This example should enable students to obtain a more realistic grasp of chemical reactivity based on a comprehension of coupled reaction processes, similar to those encountered in population dynamics or in enzymatic regulation.     

Flow Asymmetric Propargylation: Development of Continuous Processes for the Preparation of a Chiral β‐Amino Alcohol

The development of a flow chemistry process for asymmetric propargylation using allene gas as a reagent is reported. The connected continuous process of allene dissolution, lithiation, Li‐Zn transmetallation, and asymmetric propargylation provides homopropargyl β‐amino alcohol 1 with high regio‐ and diastereoselectivity in high yield. This flow process enables practical use of an unstable allenyllithium intermediate. The process uses the commercially available and recyclable (1S ,2R )‐N ‐pyrrolidinyl norephedrine as a ligand to promote the highly diastereoselective (32:1) propargylation. Judicious selection of mixers based on the chemistry requirement and real‐time monitoring of the process using process analytical technology (PAT) enabled stable and scalable flow chemistry runs.     

New trends in methodological developments in clinical chemistry

Many new techniques have been introduced in clinical chemistry. Three important new methodologies are dry chemistry, gen technology and biosensors. Solid-phase chemistry systems. The two most common solid-phase systems are the Kodak-Ektachem and the Boehringer Mannheim Reflotron. The first one is working with serum and the second one mainly with whole blood. The determination of urea and the determination of the activity of AST (GOT) will be described. The greatest problems of these systems are the quality control of the analysis and the interferences by endogenous and exogenous substances. Analysis with the aid of gen technology. The major diagnostic applications of gen technology in human disease is the detection of genetic disorders and the tumor diagnosis. The beta-thalassemia will be the example for genetic disorders and the chronic myeloid leukemia (CML) for diagnosis of a tumor. Thalassemias are a group of inherited disorders caused by the defective or absent outpout of one of the globin chains of the Hb tetramere. The CML is an example of a specific translocation of a small region of chromosome 9 bearing the abl-oncogene to chromosome 22. Biosensors in biochemical analysis. Biosensors are analytical devices that respond selectively to analytes in an appropriate sample and convert their concentration into an electrical signal. As examples an in-vivo ferrocene-mediated glucose sensor and the determination of the isoenzyme LDH5 based on an antigene-antibody reaction are described.     

Analytical Chemistry in France

Abstract

In this day and age it is not an easy task to describe in a few pages the current status of any scientific discipline. This is particularly difficult if one deals with a n area such as analytical chemistry in France which is on the upswing. The present wirteup is focused on developments in French universities since the war: we shall not deal with analytical chemistry in industry, even though chemical companies and the French Atomic Energy Commission have had a paramount influence on recent developments. Indeed, French analytical chemists are being educated mainly to serve the needs of industrial laboratories.     

The Teaching/Learning Process in Analytical Chemistry

Before teaching a course, the instructor must identify what she or he intends for the students to learn. For most analytical chemistry instructors, this usually involves an assessment of what methods and techniques to include and at what depth to cover them. There are many other skills, though, that will be important to students for their future success. Most college classes in analytical chemistry are taught in a lecture format. Techniques that can be used to improve the learning that can occur during a lecture are described. An alternative to lecturing is the use of cooperative learning. Cooperative learning offers the potential to develop skills such as teamwork, communication, and problem-solving that are more difficult to impart in a lecture format. The laboratory component of analytical chemistry courses is often an underutilized learning resource. More often than not, the lab is used to demonstrate fundamental wet and instrumental analysis techniques and develop rudimentary laboratory skills. The analytical lab should also be used to develop meaningful problem-solving skills and to demonstrate and have students participate in the entire analytical process. Ways of enhancing the analytical laboratory to include more global skills that are important to career success are described.Received January 12, 2003; accepted March 7, 2003 Published online July 16, 2003     

Tandem mass spectrometry: a convenient approach in the dosage of steviol glycosides in Stevia sweetened commercial food beverages

The use of sweeteners extracted from leaves of the plant species Stevia rebaudiana is increasing worldwide. They are recognized as generally recognized as safe by the US‐FDA and approved by EU‐European Food Safety Authority, with some recommendation on the daily dosage that should not interfere with glucose metabolism. The results presented here introduce an easy analytical approach for the identification and assay of Stevia sweeteners in commercially available soft drink, based on liquid chromatography coupled to tandem mass spectrometry, using a natural statin‐like molecule, Brutieridin, as internal standard. Copyright © 2017 John Wiley & Sons, Ltd.     

基于中国大学MOOC、慕课堂和QQ群三结合的分析化学课程在线教学实践

中国地质大学(武汉)分析化学课程团队采用国家精品在线开放课程作为课程资源、慕课堂作为智慧教学工具、QQ群作为在线讲授和辅导答疑的平台,成功地开展了分析化学课程在线教学实践。实践表明,基于MOOC、慕课堂和QQ群三结合的在线教学形式受到了学生的欢迎和喜爱,学生普遍易于接受,参与积极性高,初显教学效果较好。     

Analytical Chemistry in Israel

Abstract

Analytical chemistry in Israel is not in as good a shape as one may wish. Several attempts have been made to instill interest in this branch of the profession among faculty members, practicing chemists and students, but no great stride forward can be recorded, and on the contrary, some set-backs must be noted. Nevertheless, analytical chemistry is practiced vigorously in several laboratories, and original Israeli contributions in this field have been noted by the international community of analytical chemists. It is on this background that the present survey is being presented.     

The peculiarities of sorbtion mechanism of phenole molecules by films of PVA‐PAAN interpolymer complex

The peculiarities of sorbtion mechanism of phenole molecules by poly(vinylalcohol) and poly(acrylamide) (PVA‐PAA_N) films are examined. An analytical model of absorbtion process based on diffusive character of penetration of phenole molecules in polymer film with the following spontaneous capturing by selftuning traps is proposed. The analytical results can be easy compared with experimental data obtained by spectrophotometry method. The comparison of theory and experiment gives the average value of resulting diffusion lenght of phenole molecule during «free» life‐time <l>∼10⁻⁶ cm.     

LIBEFP: A new parallel implementation of the effective fragment potential method as a portable software library

A new high performance parallel implementation of the general Effective Fragment Potential (EFP) method in a form of a portable software library called libefp is presented. The libefp library was designed to provide developers of various quantum chemistry software packages with an easy way to add EFP functionality to the program of their choice. The general overview of the library is presented and various aspects of interfacing the library with third party quantum chemistry packages are considered. The reference implementation of common methods of computational chemistry such as geometry optimization and molecular dynamics on top of libefp is delivered in the form of efpmd program. Results of molecular dynamics simulation of liquid water using the developed software are described. © 2013 Wiley Periodicals, Inc.     

Bioorganometallic Chemistry - Transition Metal Complexes with α-Amino Acids and Peptides

A new, interdisciplinary research area has emerged known as bioorganometallic chemistry. It focuses on the introduction of organometallic fragments into biomolecules (see, for example, structure on the right). “Classical” α-amino acid and peptide ligands have proven particularly versatile, and provide access to compounds that display interesting stereochemistry. α-Amino acids and peptides can be synthesized, labeled, stabilized, or activated by organometallic fragments.     

非甾类抗炎性药物的吸附与分离分析

非甾类抗炎性药物(NSAIDs)以其良好的消炎、解热和止痛等作用,广泛应用于人类疾病的治疗中.非甾类药物参与炎症治疗的同时不能被肝脏完全代谢,大部分母体化合物及其代谢物随人体排出.大量数据表明,在环境中残留的药物会直接或间接的以食品安全问题呈现出来,这成为分析化学、材料化学等诸多领域学科重点研究课题之一.由于NSAIDs的样品基质复杂,待分析组分种类繁多,目标分析物含量低,分析人员往往借助一些样品前处理技术来对其进行吸附与分离分析.总结了近年来非甾类抗炎性药物所呈现的问题,以及目前对环境中NSAIDs的多种分离检测技术,分离检测的核心是萃取材料的选择,并综述了近年来相关对NSAIDs有效吸附分离材料的研究进展,以及对优异吸附分离材料的展望.     

History of Solution Chemistry of Japan

A historical view of the solution chemistry of Japan is described for a wide range of fields of solution chemistry, which relates to physical chemistry, inorganic chemistry, analytical chemistry, biochemistry and bioinorganic chemistry, and colloid and polymer chemistry. The works by pioneers of Japanese solution chemistry are introduced, some of which are not well recognized internationally. The influences of Japanese solution chemistry on the world and vice versa are discussed on the basis of a rather personal viewpoint. Recent activities of Japanese solution chemists at the national and international levels are also reviewed.     

Analytical Chemistry in Australia

Abstract

Analytical chemistry in Australia is alive, but its current development can be likened to that of a young and vigorous infant who needs assured supplies of food, a favourable environment and some sound guidance for growth and eventual maturity. That analytical chemistry exists in Australia and is healthy, has occurred despite the existence of most of the 19 universities in Australia! Sweden, with a population of 8.5 million, has 10 chairs in analytical chemistry in 5 main universities and analytical chemistry has been an acknowledged branch of chemistry at Swedish universities since 1960¹. Australia, with a population of 13.5 million and reasonably comparable standard of living and industrial development, has only one chair in analytical chemistry (at The University of New South Wales) in its 19 universities. However, 4 of the remaining universities (Newcastle, La Trobe, Tasmania and Queensland) have a strong interest in analytical chemistry, which is somewhat difficult to discern by the incorporation of analytical chemistry in either general chemistry or inorganic chemistry departments.     

Bioorthogonal Chemical Reporters for Selective In Situ Probing of Mycomembrane Components in Mycobacteria

The global pathogen Mycobacterium tuberculosis and other species in the suborder Corynebacterineae possess a distinctive outer membrane called the mycomembrane (MM). The MM is composed of mycolic acids, which are either covalently linked to an underlying arabinogalactan layer or incorporated into trehalose glycolipids that associate with the MM non‐covalently. These structures are generated through a process called mycolylation, which is central to mycobacterial physiology and pathogenesis and is an important target for tuberculosis drug development. Current approaches to investigating mycolylation rely on arduous analytical methods that occur outside the context of a whole cell. Herein, we describe mycobacteria‐specific chemical reporters that can selectively probe either covalent arabinogalactan mycolates or non‐covalent trehalose mycolates in live mycobacteria. These probes, in conjunction with bioorthogonal chemistry, enable selective in situ detection of the major MM components.     

Method comparison on confidence interval construction for the slope in a linear measurement model with heteroscedastic errors

In analytical chemistry, the evaluation on performance accuracy of an analytical method is an important issue. When an adjusted or new method (test method) is developed, the linear measurement error model is commonly used to compare it with another reference method. For this routine practice, the measurements on the reference method can be placed on the x‐axis, whereas those of the test method on the y‐axis, then the slope of this linear relationship indicates the agreement between them and also the performance of the test method. Under the assumption that both variables are subject to heteroscedastic measurement errors, a novel approach based on the concepts of a generalized pivotal quantity (GPQ) is proposed to construct confidence intervals for the slope. Its performance is compared with two maximum likelihood estimation (MLE)‐based approaches through simulation studies. It is shown that the proposed GPQ‐based approach is capable of maintaining the empirical coverage probabilities close to the nominal level and yielding reasonable expected lengths. The GPQ‐based approach can be recommended in practical use because of its easy implementation and better performance than the MLE‐based approaches in most simulation scenarios. Two real datasets are given to illustrate the approaches. Copyright © 2011 John Wiley & Sons, Ltd.