Orbital: The Electronic Journal of Chemistry

Partial Least Squares Regression Method to Predict Docosahexaenoic and Eicosapentaenoic Acids in Fish Oil Supplements

2024-07-01T15:21:27+00:00

Fish oil dietary supplements have been linked to various health benefits due to the high concentration of omega-3 polyunsaturated fatty acid (ω-3 PUFA). The potential use of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy with partial least squares regression (PLSR) was assessed to determine the docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and ω-3 PUFA in commercial fish oil capsules taking as a reference ¹H NMR spectroscopy values. Comparing the results achieved by interval PLS (iPLS), synergy interval PLS (siPLS), and backward interval PLS (biPLS) algorithms, it was found that siPLS provided the best results. The proposed method predicted DHA with a coefficient of determination (R²) of 0.990, root mean square error of cross-validation (RMSECV) of 0.625%, and root mean square error of prediction (RMSEP) of 1.941. EPA (R²=0.976, RMSECV=0.789%, and RMSEP=2.795%) and ω-3 PUFA (R²=0.978, RMSECV=2.667%, and RMSEP=3.980%). The results indicated that ATR-FTIR and siPLS provided a robust method that could be employed in the analysis and quality control of fish oil supplement capsules. This method has the advantage of being simple, fast, and non-destructive for quantitative analysis.

Exploring the Selective Generation of Arsenic Hydrides in Quaternary Ammonium Salt Suspension: A Didactic and Systematic Qualitative Approach Applied to Wastewater Treatment

2024-07-01T15:21:26+00:00

The treatment of laboratory waste containing arsenic compounds should be part of the chemical analysis protocol in educational and research institutions. An alternative procedure for the treatment of these residues is proposed for the development of a didactic analytical route in the detection of As³⁺, As⁵⁺, MMA (monomethylarsonic acid) and DMA (dimethylarsinic acid). The treatment is based on the coprecipitation of inorganic arsenic species with a quaternary ammonium salt (tetra-n-butylammonium perchlorate) in suspension. Detection occurred by controlling the hydride generation reactions and Atomic Absorption Spectrometry. The methylated species MMA and DMA remain in the supernatant and can be monitored by adjusting the pH, concentration of the borohydride reducer, and the use of auxiliary reducers (hydroxylamine hydrochloride and KI). Satisfactory selective detectability was obtained for each arsenic species present in the waste sample. This work contributes to the development of experiments to be implemented in Qualitative Analytical Chemistry and Instrumental Analysis classes. The results allow to approach the chemical vapor generation, which is generally not well explored in undergraduate classes. Discussion of this procedure is supported by a teaching proposal based on the theory of nascent hydrogen for inorganic arsenic species and the nucleophilic performance of the hydride ion for methylated species. This approach allows the student to contextualize important concepts such as Lewis structure, oxidation state and kinetics of arsenic hydride generation reactions. This interdisciplinary contextualization forms a common theoretical basis, preparing and enabling the student to research speciation analysis by hydride generation and to understand the most accepted theories.

Development of Agrowaste and Cellulose-based Composite Filters and Their Application in Fast Removal of Metallic Cations from Water

2024-07-02T02:06:46+00:00

Low-cost lignocellulosic filters were made from soybean hulls (SH), sugarcane bagasse fibers (SBF), cellulose nanofibers (CNF), and Kraft-bleached pulp (BP) as renewable feedstocks and applied in Cu (II) and Cd (II) removal from aqueous medium. Filtration was performed with a vacuum pump; filtration times ranged from 3 to 1200 seconds. For the same filter, the best permeate flow was 13,333 L.h.m^-2 for both cations. The best Cd (II) removal (77.2 %) was achieved within 7 seconds at a permeate flow of 5,714 L.h.m^-2. The same filter was also the best at removing Cu (II) (46.5 %), which was achieved within 7 seconds at a permeate flow of 5,714 L.h.m^-2, as well. This short time evidenced that a long contact time is not needed to achieve higher removal. The best filter was made of BP, CNF, and SH. The presence of SBF and SH increased the contact angle and decreased the solid free energy surface. By FTIR-ATR it was possible to verify with which groups present in the chemical structures of the filter components the Cd (II) and Cu (II) cations interacted best. These results demonstrate the potential use of lignocellulosic biomass for producing composites aimed at water decontamination.

Insights of Cannabinoid CBD: The Pharmacological Potential and Heterologous Expression

2024-07-01T15:21:25+00:00

In this review, a thorough approach was taken to the therapeutic potential of CBD and the possibilities of heterologous expression for its synthesis. Synthesizes the most recent discoveries on the medicinal benefits of CBD, its mode of action, and different methodologies that aim to maximize CBD production using heterologous expression systems. This review contributes to increasing knowledge about the wide range of uses of CBD and its potential in industries, including biotechnology and medicine.

The Use of Social Media as a Learning Media Based on Multiple Representation to Increase Student Learning Motivation: Article Review

2024-07-01T15:21:21+00:00

The use of social media can be used as a learning media as in the learning of chemistry. Utilization of social media as a medium of chemistry learning, is considered capable of increasing student motivation and digital literacy. This study aims to analyze the research trends of social media -based learning media, multiple representations of chemical materials and increase student learning motivation. This research method uses the Systematic Literature Review (SLR). Research data obtained from 20 articles originating from the Eric and Google Scholar database. The SLR method is used to identify, review, evaluate and interpret all studies available in the field of subjects that are of interest to a phenomenon involving certain related research questions. Based on the literature review that has been done it can be concluded that research on social media as a learning medium for hydrolysis of salt -based multiple representation can be done with various considerations of the results of previous research.

Android-based Audio-Visual Comics in Enhancing Conceptual Understanding and Motivation of Chemistry Concepts

2024-07-01T15:21:24+00:00

The complexity of chemistry arises from its abstract nature and heavy reliance on mathematical concepts, posing significant challenges for students. Combining technology with traditional teaching, comics are used as one of the educational multimedia options because of their unique ability to infuse humor, a way to convey scientific information that can captivate people's attention and interest. This study investigated the effectiveness of Android-based audio-visual comics in teaching chemical bonding among two groups of Grade 9 science class students in a public secondary school in Cebu, Philippines. Using a causal-comparative design, a 20-item pretest-posttest method was used to measure the extent of the effect of the integration on students’ conceptual understanding; meanwhile, an adapted version of the Chemistry Motivation Questionnaire-II (CMQ-II) to measure the increased motivation of the students. A semi-structured interview was utilized to gather qualitative data for teaching experiences, while a focus group discussion was used to collect students’ experiences. Quantitative results suggested that students’ conceptual understanding significantly improved after exposure to the instructional material. Meanwhile, the four components of students’ motivation significantly increased, specifically intrinsic motivation, self-efficacy, self-determination, and grade motivation. Moreover, students’ learning experiences using the instructional material discussed in the focus group discussion revealed that it helped them understand chemistry topics better and become more motivated to learn chemistry. Thus, science educators may consider using the instructional material in teaching science concepts to enhance motivation and conceptual understanding. Furthermore, future studies would have to consider the appropriateness and suitability of the instructional material in other subject areas and grade levels.