Instrumental Analytical Chemistry Research Articles

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

Teaching Experimental Instrumental Analytical Chemistry Are we forming professionals, training operators or illuding students (and ourselves)?

PENINGKATAN KUALITAS PEMBELAJARAN PADA POKOK BAHASAN ANALISIS MOLEKUL MENGGUNAKAN INFRA MERAH (IR) DAN NUCLEAR MAGNETIK RESONANCE (NMR) MELALUI PEMANFAATAN PROGRAM HYPERCHEM DAN CHEMOFFICE

Final grades of student who participated in the Course of Instrumental Analytical Chemistry in Odd Semester, Academic Year of 2022/2023 indicate a low student achievement. The objective of this study was to improve the instruction of Instrumental Analytical Chemistry Course by increasing student learning activities and student achievement on the topic of infra red and nuclear magnetic resonance analysis by utilizing HyperChem and ChemOffice Software. Student and lecturer observation sheet were used for measuring student and lecturer activities, respectively while, an essay test sheet was given to measure student cognitive ability. Student and lecturer activity scores for Cycle 1 were 22 and 27, respectively and fell in “Good” category. Student activity score rose up to the maximum score, 27 while, lecturer activity score remained in maximum score in Cycle 2. Lecturer activity already had a maximum score in Cycle 1 because the lecturer was well-prepared in the instruction as well as successful implementation of learning plan. Increasing student achievement was also recorded from Cycle 1 (average 80.2) to Cycle 2 (average 88.5). The percentage of student who gained score above 65 was 93% in Cycle 1 and went up to 100% in Cycle 2. HyperChem and ChemDraw are able to assist the instruction of Instrumental Analytical Chemistry course on the topic of IR and NMR.

Ways of Long-Term Survival of Hydrocarbon-Oxidizing Bacteria in a New Biocomposite Material-Silanol-Humate Gel.

Immobilized bacterial cells are presently widely used in the development of bacterial preparations for the bioremediation of contaminated environmental objects. Oil hydrocarbons are among the most abundant pollutants. We have previously described a new biocomposite material containing hydrocarbon-oxidizing bacteria (HOB) embedded in silanol-humate gels (SHG) based on humates and aminopropyltriethoxysilane (APTES); high viable cell titer was maintained in this material for at least 12 months. The goal of the work was to describe the ways of long-term HOB survival in SHG and the relevant morphotypes using the techniques of microbiology, instrumental analytical chemistry and biochemistry, and electron microscopy. Bacteria surviving in SHG were characterized by: (1) capacity for rapid reactivation (growth and hydrocarbon oxidation) in fresh medium; (2) ability to synthesize surface-active compounds, which was not observed in the cultures stored without SHG); (3) elevated stress resistance (ability to grow at high Cu2+ and NaCl concentrations); (4) physiological heterogeneity of the populations, which contained the stationary hypometabolic cells, cystlike anabiotic dormant forms (DF), and ultrasmall cells; (5) occurrence of piles in many cells, which were probably used to exchange genetic material; (6) modification of the phase variants spectrum in the population growing after long-term storage in SHG; and (7) oxidation of ethanol and acetate by HOB populations stored in SHG. The combination of the physiological and cytomorphological properties of the cells surviving in SHG for long periods may indicate a new type of long-term bacterial survival, i.e., in a hypometabolic state.

Development of UV-VIS Spectrophotometer Virtual Laboratory Media for Instrumental Analytical Chemistry Digital Practicum

<p><span data-preserver-spaces="true">The demands of 21st Century learning are now in the Industrial Revolution Era 4.0 with 4C learning characters. Educators must develop their creativity to improve the quality of learning so that students can be more creative in learning. </span><em>Instrumental Analytical Chemistry</em><span data-preserver-spaces="true"> is a course that studies modern instrumentation for chemical analysis. The instrumentation is unavailable in the laboratory because it is costly. This research aims to develop a virtual laboratory media UV-Vis Spectrophotometer that can be used in the digital practicum of the Instrumental Analytical Chemistry Course. The method used is development research (R & D) by adapting the multimedia model ID Hannafin & Peck, using Macromedia flash applications. This research shows that the UV-Vis Spectrophotometer virtual lab developed provides excellent feasibility results and is also effective for use in lectures and digital practicum of Instrumental Analytical Chemistry lectures. </span></p>

Teaching Microextraction Techniques During COVID-19 Pandemic through Remote Lab Strategy

Since the appearance of the COVID-19 pandemic and its subsequent stage, the changes produced in the chemistry teaching process have allowed educators to use a wide range of strategies, methodologies, and tools to promote student learning. To carry out laboratory practices, some strategies reported include the use of simulators and educational software, as well as the development of remote lab activities. In recent years, the teaching of microextraction techniques and the greening of the sample treatment process represent an important topic in instrumental analytical chemistry courses, incorporating green chemistry topics in the curricula. In this context, a hands-on activity through a kit of materials, equipment, and reagents delivered to students for teaching microextraction techniques during the pandemic’s learning conditions is presented. The activity was designed to extract a food coloring dye applying four microextraction techniques, including solid-phase extraction (SPE), solid-phase microextraction (SPME), in-tube solid-phase microextraction (IT-SPME), and micro polymeric magnetized bar adsorptive extraction (μ-PMBAE). Finally, for quantitative analysis, a colorimetry and absorbance-based experiment through image acquisitions and RGB analysis was used. The experiments were applied as extracurricular activities, and students’ feedback was fruitful due to the enthusiasm that it produced in them to carry out laboratory tasks after so much time of confinement. Among the successful points of the activity, it is possible to mention the ease of carrying out the experiments from home and the application of green sample treatment techniques that minimize the use of materials and reagents.

Applicability of multivariate calibrations in atomic emission spectrometry with arc discharge

Recent achievements in the field of instrumental analytical chemistry are associated with the development of devices that register a variety of analytical signals and use a variety of information processing methods. Hence, the use of advanced mathematical techniques for the treatment of a large amount of data obtained is required. Multivariate approaches are of the greatest interest for the Earth and Life sciences since most studies are based on measuring the chemical composition of complex natural organomineral substances and describing their compositions, on which their properties directly depend. Natural objects are multidimensional in their origin, so several analysis methods and one-dimensional processing techniques are traditionally used for their study and analytical control in order to achieve the required accuracy of the results. The special mathematical techniques for processing the analytical signals in emission spectra objectively reduces costs while improving accuracy. The authors in the current paper attempt to assess the need for the use of multivariate calibrations in atomic emission spectrometry with arc discharge while simultaneously analyzing different types of objects. Different variants of calibrations are considered for two techniques of direct atomic emission determination of F as well as Li, P, B, Mn, Ni, Co, V, Cr, W, Mo, Sn, Ga, Pb, Cu, Zn, Ag, Sb, As, Tl, Ge, Bi and Cd (22 elements) in powders of rocks, loose and bottom sediments, soils, ashes, gold-silver ores and products of their processing.

Problem- and case-based scenarios in teaching instrumental analytical chemistry: A two-level approach to trialling

Rapid technological development introduced dramatic changes in teaching analytical chemistry. While instruction of core analytical chemistry continues to be of significance, implementation of additional applied approaches helps to bridge the gap between the theoretical nature of academic teaching, and a practical way typical for employment. Although the use of problem- and case-based learning scenarios in chemistry have shown to be beneficial, evidence of their application for the teaching of instrumental analytical subjects remains limited. One of the main concerns in developing new curriculum disciplines involving problem- and case-based learning regards the way of testing these teaching approaches before implementation. In this report, we introduce a two-step model for trialling of problem- and case-based scenarios for the teaching of applied analytical chemistry, which was helpful in the development of several chemistry modules for both undergraduate and postgraduate curricula.

Overview of Erasmus+ NETCHEM project: ICT networking for overcoming technical and social barriers in instrumental analytical chemistry education.

The paper briefly presents goals, activities, challenges, and outcomes of the NETCHEM project ( http://www.netchem.ac.rs/ ) that was co-funded by the Erasmus+ Program of European Union (573885-EPP-1-2016-1-RS-EPPKA2- CBHE-JP). The project has been started in October 2016 and with extension lasted until April 2020. Western Balkan region has been targeted by upgrading capacities for education and research in environmental and food analysis in cooperation with partners from France, the UK, and Czech Republic. NETCHEM platform providing Web Accessed Remote Instrumental Analytical Laboratories (WARIAL) network, Database service and Open education system was created in order to improve the cooperation, educational, and research capacities of Higher Education Institutions involved, but also targeting whether audience not only from academic domain but from industry as well. The NETCHEM platform is free for access to public; thus, the external users to NETCHEM consortium can not only see its content but also actively participate, enter Database and WARIAL network, and upload their own educational/research material.

Teaching Instrumental Analytical Chemistry in the Framework of COVID-19: Experiences and Outlook

Significant changes in the teaching–learning process have occurred since the appearance of the COVID-19 pandemic caused by the SARS-CoV 2 coronavirus, due to the limited mobility and closure of uni...

Teaching Instrumental Analytical Chemistry during COVID-19 Times in a Developing Country: Asynchronous versus Synchronous Communication

On Mar. 19, 2020, Argentina’s government decided to close academic institutions for an indefinite time in an attempt to contain the spread of the COVID-19 pandemic. Since the University established that, when the quarantine ends, 5 weeks will be reserved for face-to-face activities that could not be carried out virtually (laboratory lessons and final exams), the main focus on the online activities was in the theoretical lessons. For the Instrumental Analytical Chemistry course both synchronous strategy such as questions and answer sessions and asynchronous communication such as Microsoft PowerPoint presentations with explicative audios, simulated assays, and assignments were adopted. A survey conducted with our students indicated that although synchronous lessons provided face-to-face interaction, the lack of good Internet connectivity was the main weakness of this strategy. On the other hand, asynchronous lessons did not require very high bandwidth networks and had the possibility of stopping the lesson and continuing it later. However, students’ lack of interaction with their teachers was the main drawback of this type of communication. Most of the students pointed out that a blend of synchronous and asynchronous communication is more desirable for Instrumental Analytical Chemistry lessons than asynchronous or synchronous communication separately.

El modelo “clase invertida” en química analítica

<p>En la actualidad se trata de trasladar el eje central del acto pedagógico del docente hacia el alumno, transformándolo así en responsable activo de la adquisición del conocimiento. Es por ello que se implementó el modelo de clase invertida en la enseñanza de un tema fundamental en el área de la química analítica instrumental con el fin de mejorar el proceso de enseñanza - aprendizaje del mismo. Se trabajó con un grupo de 15 alumnos de la Licenciatura en Química de la Universidad Nacional de Tucumán, Argentina. Se escogió el tema de espectrometría de absorción atómica para la aplicación del modelo aula invertida. La experiencia se evaluó mediante dos herramientas. La primera fue la elaboración de un informe final global del tema que los estudiantes presentaron en forma individual y en el que se abarcaron contenidos teóricos y prácticos. La otra fue la realización de una encuesta de opinión a los alumnos en la que se indagó sobre su percepción respecto a la metodología de trabajo y los resultados alcanzados por ellos. Desde el punto de vista de los docentes involucrados, la experiencia fue muy positiva en cuanto a la adquisición de los conocimientos y sobre todo en el desarrollo de la práctica.</p>

Experimental evidence of matrix effects in total-reflection X-ray fluorescence analysis: Coke case

Total-reflection X-ray Fluorescence (TXRF) analysis is an established method used in instrumental analytical chemistry. Benefits and drawbacks of the method are well known. They have been described in the past and presented in many papers in the last decades. One of the most impressive features, not common to other X-ray fluorescence methods, is the absence of matrix effects and therefore the use of a simple and reliable quantification. Nevertheless, in some cases, TXRF suffers from matrix effects if the sample amount exceeds the condition of a transparent film-like sample or simply if the system is overloaded. In this work, we present the results of TXRF analysis of the different components of beverages summarized under the generic name ‘Coke’. Some of them contain up to 10% of sugars and others only mg-amounts of sweeteners. Different sample pre-treatments were applied in order to get reliable results of trace element contents in Coke. A significant deviation of the concentration of elements detected by their characteristic X-ray radiation between 1 and 5 keV (e.g. for P, S, K and Ca) was observed depending on the sample amounts and sample preparation. This behaviour could only be explained by the presence of matrix effects. Transmission curves depending on the residual film-like sample after drying the beverages were calculated and compared with measurements. The obtained deviations for the different sample preparations and different amounts presented to the spectrometer are in good agreement with the theory. TXRF results obtained after microwave digestion for traditional and light Coke were validated by ICP-MS analyses.

Construcción de un potenciostato de bajo costo para estudios de inhibición de corrosión de acero: determinación del potencial de corrosión y mediciones cronoamperométricas

Knowledge integration is the central duty of chemistry education and is in this context where the investigation surrounding steel corrosion inhibition bring us the opportunity to integrate knowledge from electrochemical kinetics, Organic chemistry, Instrumental analytical chemistry and electronics via the construction of a low cost potentiostat and the use of this in studies of the anticorrosive properties of atropine sulphate with carbon steel in solution. Due that this experience is going to allow the student the determination of the corrosion potential and chronoamperometric behavior of carbon steel SAE 1010 in 0.9% NaCl solution in presence and absence of atropine sulphate in a standard electrochemistry cell of three electrodes.

Development of a Handmade Fluorometer and Proposals for its Application in Practical Courses of Instrumental Analytical Chemistry in the Graduation

Development of a Handmade Fluorometer and Proposals for its Application in Practical Courses of Instrumental Analytical Chemistry in the Graduation

Using a Systematic Approach To Develop a Chemistry Course Introducing Students to Instrumental Analysis

A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical training via experimentation. Problem-based learning and cooperative-learning methods are applied in both the classroom and laboratory aspects of the course. In addition, some reflections and best practices are presented on how to encourage students to learn actively. Overall, a student-centered environment is proposed that aims to cultivate students’ practical abilities and individual talents.

Fatores químicos e físicos que afetam a contaminação por chumbo e cobre em água potável: uma abordagem para o estudo de caso em química analítica

Lead and copper concentrations in drinking water increase considerably on going from municipality reservoirs to the households sampled in Ribeirao Preto (SP-Brazil). Flushing of only 3 liters of water reduced metal concentrations by more than 50%. Relatively small changes in water pH rapidly affected corrosion processes in lead pipes, while water hardness appeared to have a long-term effect. This approach aims to encourage University teachers to use its content as a case study in disciplines of Instrumental Analytical Chemistry and consequently increase knowledge about drinking water contamination in locations where no public monitoring of trace metals is in place.

Juicing the Juice: A Laboratory-Based Case Study for an Instrumental Analytical Chemistry Course

A young, inexperienced Food and Drug Administration (FDA) chemist is asked to distinguish between authentic fresh orange juice and suspected reconstituted orange juice falsely labeled as fresh. In an advanced instrumental analytical chemistry application of this case, inductively coupled plasma (ICP) spectroscopy is used to distinguish between the fresh and reconstituted samples based on their calcium and magnesium concentrations. Students working in teams are given the challenge posed in the case to the FDA chemist. They are charged with designing an experimental procedure, obtaining and analyzing the needed data, and writing a formal report. This case study requires students to conduct themselves in the same manner chemists would in the “real world” when faced with a new and challenging problem. Experimental procedures developed by student teams lead to the correct identification of unknowns a majority of the time. Assessment data indicate this case study elicited positive interest and interactions.

Promoting Active Learning by Practicing the “Self-Assembly” of Model Analytical Instruments

In our upper-year instrumental analytical chemistry course, we have developed “cut-and-paste” exercises where students “build” models of analytical instruments from individual schematic images of components. These exercises encourage active learning by students. Instead of trying to memorize diagrams, students are required to think deeply about the design and function of each of the components of the instruments they assemble, with particular emphasis on how different components interact. Students have found these exercises to be an engaging method that promotes improved understanding of instrument design. We provide a description and examples of these exercises, including a library of over 300 electronic images of components from which other instructors and their students can build a wide variety of instruments. In addition to student exercises, instructors can use these images to create custom diagrams for lectures or other course materials.

LC-QqLIT MS analysis of nine sulfonamides and one of their acetylated metabolites in the Llobregat River basin. Quantitative determination and qualitative evaluation by IDA experiments

Robust instrumental analytical chemistry and the subsequent development of improved analytical methodologies and extraction procedures have enabled the detection at environmental levels of new emerging contaminants, for example pharmaceuticals. The objective of this study was to explore the potential of liquid chromatography-tandem quadrupole-linear ion trap (LC-QqLIT MS) for quantitative determination of nine sulfonamides (SAs) and one acetylated metabolite in surface water from the Llobregat River and one of its main tributaries, the Anoia River, in Catalonia (Spain). A total of 21 samples were taken in three sampling campaigns. Recoveries ranging from 26% to 123% were calculated for the SAs studied, and method limits of detection (MLODs) achieved were in the range 0.05-0.2 ng L(-1). Through the different campaigns, concentrations ranged from 0.74 ng L(-1) (sulfamethizole) to 2,482 ng L(-1) (sulfamethazine) in the Llobregat River, and from 0.27 ng L(-1) (sulfamethizole) to 168 ng L(-1) (sulfamethoxazole) in the Anoia River. Sulfamethoxazole and sulfapyridine were the two SAs most frequently detected (80% and 71% respectively). N(4)-acetylsulfamethazine was detected in both rivers, but with different frequencies (4% of the samples from the Anoia River and 43% of those from the Llobregat River). Information-dependent acquisition (IDA) experiments were also developed in order to obtain enhanced product-ion spectra in surface water samples.

Reconhecimento de padrões por métodos não supervisionados: explorando procedimentos quimiométricos para tratamento de dados analíticos

An activity for introducing hierarchical cluster analysis (HCA) and principal component analysis (PCA) during the Instrumental Analytical Chemistry course is presented. The posed problem involves the discrimination of mineral water samples according to their geographical origin. Thirty-seven samples of 9 different brands were considered and the results from the determination of Na, K, Mg, Ca, Sr and Ba were taken into account. Non-supervised methods for pattern recognition were explored to construct a dendrogram, score and loading plots. The devised activity can be adopted for introducing Chemometrics devoted to data handling, stressing its importance in the context of modern Analytical Chemistry.