Concept Of Analytical Chemistry Research Articles

Effect of Gender on Students’ Attention and Academic Performance in Analytical Chemistry Using Collaborative-Predict-Explain-Observe-Explain (CPEOE)

This research investigated the possibility of enhancing senior secondary school students’ academic performance irrespective of gender in analytical chemistry concept using Collaborative-Predict-Explain-Observe-Explain (CPEOE). The study adopted a quasi-experimental research design. Analytical Chemistry Attention Inventory (ACAI) and Analytical Chemistry Performance Test (ACPT) were the instruments used for data collection. Cronbach Alpha was used to ascertain the reliability index of ACAI which gave reliability value of 0.87. The internal consistency of ACPT was tested using Kuder-Richardson (KR-21) formula which yielded a reliability value of 0.96. The population was 7,152 SS2 students offering chemistry in Makurdi, Benue State, Nigeria. A sample of 157 students drawn from 3 schools in Makurdi Local Government Area of Benue State, Nigeria was selected using multi-stage sampling techniques. Four research questions and four null hypotheses guided the study. The research questions were answered using Mean and Standard Deviation scores while the null hypotheses were tested at 0.05 level of significance using results from Analysis of Covariance (ANCOVA). The study revealed among others, that there was no significant difference between the mean attention rating of male and female students taught analytical chemistry {F1, 78 = 1.020, P>0.05}. It was also revealed that that there is no significant difference between the mean academic performance of male and female students taught analytical chemistry using CPEOE {F1, 78 = 4.890, P>0.05}. It was recommended among others that since CPEOE is not gender sensitive. Hence, both male and female students should be involved in CPEOE classroom to enhance their attention and academic performance in analytical chemistry. Serving teachers should be encouraged to use CPEOE in teaching analytical chemistry concepts.

Eco‐Friendly Analytical Approaches for the Quantification of Molnupiravir and Favipiravir Using Capillary Zone Electrophoresis and Derivative Ratio Spectrophotometry

AbstractDesigning new validated analytical procedures with a focus on many objectives, such as simplicity, environmental friendliness, analytical effectiveness, and sustainability, has grown to be a top priority in quality control departments. Applying green and white analytical chemistry concepts is no longer a luxury. In this report, two new approaches, Capillary Zone Electrophoresis (CZE) with Photo Diode Array (PDA) detection and derivative ratio spectrophotometric methods, are established and validated for the simultaneous analysis of molnupiravir (MLP) and favipiravir (FAV) in bulk, single dosage forms, and their expected combined dosage forms. For the two drugs, linearity ranges of 5–50 μg/mL and 1–30 μg/mL were achieved using the CZE and spectrophotometric methods, respectively. Both techniques have been validated and used for the estimation of the two medications in lab‐made capsules in accordance with the International Council for Harmonization's (ICH) recommendations. Seven assessment models were used to evaluate the greenness and sustainability of the introduced approaches compared to three previously published HPLC, chemometric, and HPTLC techniques. ChlorTox and BAGI tools are applied for the first time for the evaluation of an analytical procedure. Higher green and sustainable qualities were declared by suggested approaches than by earlier ones.

Optimizing contact angle changes for droplet actuation by optoelectrowetting (OEW): A numerical multi-parameter analysis

With the transition of fluid-capillary-based “Lab on a chip 1.0″ concepts in analytical chemistry to “Lab on a chip 2.0″ approaches relying on distinct fluid droplets (“digital microfluidics”, DMF), the need for reliable methods for droplet actuation has increasingly come into focus. One possible approach is based on “electrowetting on dielectric” (EWOD). This technique has the disadvantage that any possible desired later positions of the droplets on the chip have to be defined prior to chip realization because one of the EWOD electrode layers has to be structured accordingly. “Optoelectrowetting” (OEW) goes a step further in the sense that the later droplet positions do not have to be known before, and none of the electrode layers has to be structured. Instead, the electrical parameters of the layer sequence can be altered locally by an impinging (and movable) light spot. Although some research groups have succeeded in demonstrating OEW actuation of droplets, the optimization of the relevant parameters of the layer sequence and the droplet – at least half a dozen parameters altogether – is tedious and not straight-forward. In this contribution, for optimization purposes, the equations governing OEW are revisited and altered again, e.g., by numerical implementation of the experimentally well-known saturation of the contact angle change. Additionally, a Nelder-Mead algorithm is applied to find the parameters, on which the optimization has to focus to maximize contact angle changes and, thus, mechanical forces on the droplets. The numerical investigation yields diverse results, e.g., the finding that the droplet’s contact area on the dielectric layer has a strong influence on the contact angle change and the question whether the droplet is pulled or pushed. Moreover, the interplay between frequency and amplitude of the applied rectangular alternate voltage is important for optimization.

Scientific attitudes in chemistry learning: A systematic literature review

This systematic review analysis study aimed to examine the scientific attitudes in chemistry learning. The method used a Systematic Literature Review which consists of 5 stages adopted from Denyer and Tranfield. The main criteria for the selection of articles are scientific attitude in the field of chemistry learning with a period of 2012 until 2023 from the well-known national and international database. There were 29 articles were obtained that fit into the criteria. The article’s aspect focused on the parameters such as aim, sample level, instructional method, instruments, and chemistry subject. The result showed that the attitude scale is the most instrument that can be used to measure scientific attitude in chemistry learning. Meanwhile, PBL has become the most instructional method that has been used to enhance scientific attitude. Moreover, the studies mostly aim to investigate the influence of teaching methods on scientific attitudes. Most researchers involve high school students in scientific attitude research on analytical chemistry concepts. There are different codes for each theme of scientific attitudes. Thus, the review helps to evaluate the instrument and instructional methods in chemistry learning and also provides recommendations for examining students’ scientific attitudes in further explorations.

The application of experimental design and green analytical chemistry in HPLC strategy for the determination of five drugs used in antimicrobial combination therapy

Antimicrobial resistance is a significant global issue that has increased mortality rates over the past 100 years. One of the strategies followed to overcome this problem is to use antimicrobial combination therapy with different action modes that can synergize for successful treatment in emergent situations. Ciprofloxacin, Tinidazole, Dexamethasone Sodium Phosphate, Diloxanide Furoate, Metronidazole, and their different combinations are commonly used as effective combination therapies in critical cases. Hence, it is essential to establish an appropriate technique for their simultaneous analysis. The application of green analytical chemistry concepts was also an important issue that should be considered in the development of analytical methods. Hence, a new green micellar organic solvent-free HPLC methodology has been devised to analyze the specified five drugs simultaneously in both their authentic forms and combined pharmaceutical formulations. Response surface methodology was used to investigate the influence of different variable factors on chromatographic performance. Central composite design was utilized for response optimization. A Symmetry C18 column (3.5 µm, 4.6 × 75 mm), an isocratic mixed–micellar mobile phase composed of (70.76 mM of sodium dodecyl sulphate and 21.38 mM of Brij-35, 2.76 pH, and 40 ± 2 °C at a flow rate of 1 mL/min, were the ideal separation circumstances for analytesʹ separation at 260 nm as a chosen detection wavelength. The described approach was satisfactorily utilized todetermine various pharmaceutical formulations of the specified medications in combination. ICH guidelines were followed during the method's validation. Analytical Greenness Measure (AGREE) and Green Analytical Procedure Index (GAPI) fundamentals were followed to judge the developed methodology's greenness.

In-situ Diffusive Gradients in thin-films passive sampling coupled with ex-situ small-sized electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry as green and white method for the simultaneous determination of labile species of toxic elements in surface water

This study presents for the first time the coupling between in-situ Diffusive Gradient in Thin-film (DGT) passive sampling technique and ex-situ small-sized instrumentation based on electrothermal vaporization capacitively coupled plasma microtorch optical emission spectrometry (SSETV-μCCP-OES) for the simultaneous determination of Cd, Pb, Cu, Zn and Hg in surface water. Unique features of the DGT-SSETV-μCCP-OES are low power and low Ar consumption for plasma generation (15 W, 150 mL min−1) and significant improvement of the detection limits following DGT passive sampling. The new method was validated in terms of river water analysis in comparison with graphite furnace atomic absorption spectrometry and thermal decomposition atomic absorption spectrometry. Combining the abilities of preconcentration by in-situ Chelex-DGT passive sampling with plasma microtorch equipped with a low resolution microspectrometer provided multielemental simultaneous determination with detection limits of (μg L−1) 0.01 (Cd, Zn and Hg), 0.02 (Cu) and 0.07 (Pb) in water, at least one order of magnitude better than using grab sampling without preconcentration. It was possible the quantification of labile fraction of priority hazardous metals (Cd, Pb) in river water below the instrumental limits of detection (μg L−1) of 0.12 and 0.80 obtained in SSETV-μCCP-OES without DGT sampling. The precision of the method was in the range 15.3–22.4% (combined uncertainty), while the accuracy was 95–103% and trueness of 27–33% (expanded uncertainty, k = 2). The DGT-SSETV-μCCP-OES coupling proved to be an ideal and powerful tool for surface water analysis in compliance with green and white analytical chemistry concepts. The application of the RGB-12 algorithm provided very good red/green (AGREEprep)/blue/white scores (%) of 100/80/98/93, determined primarily by in-situ DGT passive sampling, very good detection limits and cost-effective SSETV-μCCP-OES instrumentation.

Design, implementation, and evaluation of an online flipped classroom with collaborative learning model in an undergraduate chemical engineering course

Active learning methods are known to improve motivation, engagement, and student performance in traditional classrooms. However, the COVID-19 pandemic compelled students to continue their studies through an online setting wherein teaching is undertaken remotely and on digital platforms. In this study, the design and implementation of flipped classrooms supported with collaborative learning was evaluated for the remote instruction of Analytical Chemistry. The flipped classroom was designed to include pre-recorded lectures, individual self-assessment questions and in-class group activities (polls and quiz bee). Word problems were given as collaborative tasks to improve the students’ interactions on the learning content. The impact on learning of these instructional practices was evaluated based on students’ learning experience and academic performance, and the instructors’ reflection. The survey at the end of the term gathered quantitative and qualitative data regarding students’ experiences with flipped classroom and peer collaboration methods. The students’ feedback indicated that participation in group collaborative activities had a positive impact on their comprehension of Analytical Chemistry concepts and calculations. Majority of the students indicated that group collaboration was immensely helpful in enhancing communication skills and improving their ability to apply what they had learned in class to solving difficult word problems. In addition, students underscored the importance of pre-recorded videos for their self-paced learning, and synchronous sessions to increase their engagement and motivation. On the other hand, several students perceived flipped classrooms as very demanding and challenging in terms of the required output submissions given the short 6-week term. Overall, the combination of these active-learning methods had a positive impact on the remote-learning environment, but potential drawbacks of online active learning interventions on student attitudes were also present. Therefore, careful integration of these instructional practices into online courses will help improve the students’ learning experience.

Design of an Experimental Study for the Simultaneous Determination of Cefepime, Piperacillin and Tazobactam Using Micellar Organic Solvent-Free HPLC

Application of Sustainable analytical chemistry concepts has become crucial in order to remove the environmentally harmful impacts originating from the routine use of analytical techniques. Here, a new LC method is developed and its parameters are analyzed, depending on a mixed micellar mobile phase. This was primarily aimed at getting rid of the use of organic solvents in conventional routine analyses. Combinations of tazobactam (TZB) with piperacillin (PPC) or cefepime (CFM) are commonly used as effective antimicrobial therapies, especially for resistant strains. Therefore, the three drugs were separated and quantified using an organic solvent-free mobile phase. The mixed micellar mobile phase was comprised of 15 mM Brij-35 with 38 mM SDS, adjusted to pH 3.5. Separation was performed by HPLC on monolithic RP-C18 column Chromolith® Performance RP-18e (100 mm × 4.6 mm) at a rate of 1 mL per minute of flow in conjunction with a measurement wavelength 210 nm. The method was found valid and applicable in accordance of precision, and accuracy within ranges of 5–100 µg mL−1 for PPC and CFM and of 0.625–12.5 µg mL−1 for TZB. The quality-by-design technique was used to analyze the effect of modifying the mixed micellar ratios on separation efficiency and conclude their behavior. Finally, the suggested approach was assessed applying the green analytical procedure index against the greenest published methodology to show superiority.

Two Green Micellar HPLC and Mathematically Assisted UV Spectroscopic Methods for the Simultaneous Determination of Molnupiravir and Favipiravir as a Novel Combined COVID-19 Antiviral Regimen.

Following the spread of the COVID-19 pandemic crisis, a race was initiated to find a successful regimen for postinfections. Among those trials, a recent study declared the efficacy of an antiviral combination of favipiravir (FAV) and molnupiravir (MLP). The combined regimen helped in a successful 60% eradication of the SARS-CoV-2 virus from the lungs of studied hamster models. Moreover, it prevented viral transmission to cohosted sentinels. Because both medications are orally bioavailable, the coformulation of FAV and MLP can be predicted. The developed study is aimed at developing new green and simple methods for the simultaneous determination of FAV and MLP and then at their application in the study of their dissolution behavior if coformulated together. A green micellar HPLC method was validated using an RP-C18 core-shell column (5 μm, 150 × 4.6 mm) and an isocratic mixed micellar mobile phase composed of 0.1 M SDS, 0.01 M Brij-35, and 0.02 M monobasic potassium phosphate mixture and adjusted to pH 3.1 at 1.0 mL min−1 flow rate. The analytes were detected at 230 nm. The run time was less than five minutes under the optimized chromatographic conditions. Four other multivariate chemometric model methods were developed and validated, namely, classical least square (CLS), principal component regression (PCR), partial least squares (PLS-1), and genetic algorithm–partial least squares (GA–PLS-1). The developed models succeeded in resolving the great similarity and overlapping in the FAV and MLP UV spectra unlike the traditional univariate methods. All methods were organic solvent-free, did not require extraction or derivatization steps, and were applied for the construction of the simultaneous dissolution profile for FAV tablets and MLP capsules. The methods revealed that the amount of the simultaneously released cited drugs increases up until reaching a plateau after 15 and 20 min for FAV and MLP, respectively. The greenness was assessed on GAPI and found to be in harmony with green analytical chemistry concepts.

Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)

Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)

Context-Based Testing as Assessment Tool in Chemistry Learning on University Level

Testing as an assessment technique has been widely used at all levels of education—from primary to higher school. The main purpose of the paper is to evaluate the effect of context-based testing in teaching and learning of analytical chemistry in a Russian university. The paper formulates the objectives of context-based testing, discusses its features and compares with conventional testing; proposes a model of constructing and administering context-based testing; provides examples of context-based tests. The experiment was conducted at the Ural Sate University of Economics (Russia) with bachelor’s degree students with nonscience majors. Students were assigned to one of the experimental conditions: in the control group, traditional tests were carried out, while the experimental group students experienced context-based testing. The statistical data—students’ test scores—obtained at all stages of the experiment were analyzed on the basis of statistical criteria (Shapiro–Wilk, Student’s T, Fisher). The findings of our experiment enable us to answer the guided research questions. Context-based testing may be considered as an essential component of context-based teaching and learning. In comparison with conventional testing, context-based testing could impact developing knowledge of fundamental analytical chemistry concepts and contribute to more solid knowledge.

Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)

Abstract Recommendations are given for metrological terminology in analytical chemistry. Analytical chemistry is defined, and concepts related to laboratory practice are termed and defined. Recommendations are given concerning the terminology of quality assurance in analytical chemistry. Terms draw on the extensive quality literature, particularly from ISO.

Design-Based Learning Framework for Introducing Factorial Experimental Design and Lab-on-a-Chip Separations in an Instrumental Chemistry Laboratory

Lab-on-a-chip devices are a critical and emerging chemical technology. New pedagogical tactics that effectively capture both analytical chemistry concepts along with the design elements unique to these devices are necessary for effective integration in the undergraduate chemistry curriculum. This article develops a design-based learning laboratory exercise to concurrently introduce analytical miniaturization, chemical separations, and formal factorial design of experiment methods in an Introduction to Instrumental Analysis course. A new student-accessible lab-on-a-chip fabrication platform using a benchtop laser cutter allows for rapid, iterative, and safe production of student-designed microchip capillary electrophoresis devices in minutes. Student teams used a full factorial experimental design approach to efficiently screen three experimental variables of their choice when evaluating the separation speed of their own lab-on-a-chip devices. This laboratory exercise has been successfully implemented on three occasions over the past several years at Colorado College. Both reflective and performance-based assessment methods suggest this exercise is an effective pedagogical approach for realizing the intended learning outcomes.

Metrological and quality concepts in analytical chemistry

Metrological and quality concepts in analytical chemistry

The Flint, Michigan Water Crisis as a Case Study to Introduce Concepts of Equity and Power into an Analytical Chemistry Curriculum

This work developed the Flint, Michigan water crisis as a modular case study for teaching traditional analytical chemistry concepts through the medium of environmental justice, power, and equity. A...

Decompartmentalized Knowledge and Core Analytical Chemistry Concepts

Decompartmentalized Knowledge and Core Analytical Chemistry Concepts

A fotografia como recurso didático para contextualizar conceitos de Química Analítica

A Química Analítica é considerada um dos componentes curriculares mais difíceis na graduação em Química, principalmente por estar centrada no equilíbrio químico. Assim, este estudo aborda a inserção da Fotografia Científica Observatória na contextualização dos conceitos de Química Analítica, como facilitador do ensino e da aprendizagem, junto à 18 estudantes do Ensino Superior na Universidade Federal da Fronteira Sul, para observação do equilíbrio químico presente no cotidiano. De forma geral, os acadêmicos se restringiram em trazer exemplos mais presentes em livros didáticos. No entanto, a análise das fotografias apresentadas pelos estudantes mostrou a importância de motivar os estudantes a buscar conhecimento de forma contextualizada e intencional.

Harmonizing analytical chemistry and clinical epidemiology for human biomonitoring studies. A case-study of plastic product chemicals in urine

There is an interdisciplinary interface between analytical chemistry and epidemiology studies with respect to the design, execution, and analysis of environmental epidemiology cohorts and studies. Extracting meaningful results linking chemical exposure to human health outcomes begins at study design and spans the entire workflow. Here we discuss analytical experimental design from an exposure science perspective, and propose a reporting checklist for the design of human biomonitoring studies. We explain key analytical chemistry concepts of blanks and limits of reporting and present a case series of plastic product chemical exposure in prenatal urine specimens from the Barwon Infant Study.

Designing ColorX, Image Processing Software for Colorimetric Determination of Concentration, To Facilitate Students’ Investigation of Analytical Chemistry Concepts Using Digital Imaging Technology

This work combines laboratory quantitative analysis of colored solutions and common devices for digital imaging (digital or web cameras or mobile phones, i.e., smartphones). ColorX software, specia...

Downscaling of Industrial Turbo-Distillation to Laboratory Turbo-Clevenger for Extraction of Essential Oils. Application of Concepts of Green Analytical Chemistry.

In the effort of innovation towards green analytical chemistry concepts and considering the six principles of green extraction, the industrial turbodistillation process was downscaled into a laboratory apparatus turbo-Clevenger (TC) for the extraction of essential oils. Turbodistillation is used as an industrial purpose for the extraction of essential oils from hard matrixes such as wood, barks, seeds. In this work, a TC and the conventional technique of hydrodistillation (HD, Clevenger apparatus) are used for the extraction of essential oils from three spices with hard structures (Illicium verum, Schinus terebinthifolius, and Cinnamomum cassia) and are compared. This study shows that the essential oils extracted by TC in 30 min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydrodistillation in 3 h. This process, which gave a reduced extraction time, was perfectly adapted to the extraction of hard matrixes.