Principles Of Green Chemistry Research Articles

Food grade pilot scale strategy for non-thermal extraction and recovery of phenolic compounds from orange peels

The orange peels (OP) derived from orange juice factories consist of several polymers and molecules that could be recovered using a biorefinery approach. This study presents a pilot-scale strategy for the extraction and recovery of phenolic compounds from OP, aiming to demonstrate a sustainable, non-thermal process that operates without the use of solvents and complies with food-grade standards. The extraction process was conducted in a food-grade manner on a 1000 L scale, starting with the enzymatic hydrolysis of pectin in the biomass, followed by ultrasound-assisted extraction (UAE) at 54 Ws/gslurry and 20 °C. Solid/liquid separation via decanter centrifuge allowed to recover the solution containing the phenolic compounds, that was further purified via sequential cross-flow microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). The final product was analysed by HPLC-ESI-TOF-MS, revealing an interesting phenolic profile with several potential bioactivities and a total polyphenol content (TPC) of 3.3 g/L. The food-grade analysis confirmed the potential application of the final product in food-related processes, such as food packaging or fortification. This work highlights a scalable and environmentally friendly method to convert agro-food waste into valuable bioactive compounds, aligning with green chemistry principles and zero-waste strategies.

Photocatalyzed Acylation of Azauracil Derivatives with Aldehydes.

A novel approach for the acylation of azauracil derivatives with aldehydes has been developed utilizing sodium decatungstate (NaDT) as a photocatalyst. This method demonstrates broad substrate tolerance and yields moderate to excellent outcomes. Notably, it aligns with green chemistry principles by eliminating oxidants, utilizing eco-friendly energy sources, and offering high scalability and operational simplicity.

Determination of persistent organic pollutants in urban and peri-urban wastewater sludge: environmental and carcinogenic human risk assessment in the case of land application.

The management of digested sludge derived from treatment water plants is a problem worldwide due to the possible transfer of contamination from sludge to amended soil and, in turn, to humans. Within this work, through a chemometric experimental design, a robust GC-MS method for the simultaneous determination of two classes of micropollutants of concern (polycyclic aromatic hydrocarbons-PAHs-and polychlorinated biphenyls-PCBs-including dioxin-like compounds) was developed using microwave-assisted extraction (MAE). The method, which showed interesting greenness features in compliance with the 12 principles of Green Chemistry, allowed PCB and PAH extraction with recoveries higher than 75% (RSD < 14%) with method detection limits between 4.6 and 11.5µgkg-1 (PAHs) and between 6.9 and 13.7µgkg-1 (PCBs), without preconcentration. The matrix effect was below 20%. The validated protocol allowed the characterization of two digested sludges sampled in an urban and a peri-urban district, representative models of two scenarios of different anthropic impacts. This study highlighted higher contamination for the sludge derived from the urban area, accounted for by the 4-ring PAHs. In addition, since carcinogenic PAHs were detected, the environmental risk (by mean of the comparison of predicted vs predicted no-effect concentrations) and the carcinogenic human risk from dermal contact (through the calculation of the adsorbed lifetime average daily dose) were assessed in the case of soils amended with the sludges considered, pointing out that the measured concentrations do not pose a risk.

Green Nanoengineered Fabrics: Waste-Derived Polyphenol-Zinc@ Silica Core-Shell Reactive Janus Nanoparticles for Functional Fabrics.

Fabricating Janus nanoparticle-functionalized fabrics with UV protection, strength enhancement, self-cleaning properties, and wash durability, with a biocompatible nature, is crucial in modern functional fabrics engineering. Particularly, tailoring multifunctional nanoparticles capable of exhibiting several distinct properties, utilizing low-cost raw materials, and adhering to green chemistry principles is pivotal. A fabrication strategy for developing multifunctional reactive Janus nanoparticles, utilizing waste-derived natural polyphenol (quercetin-3-glucuronide, myricetin-3-galactoside, gossypin, phlorizin, kaempferol, myricetin-3-arabinoside)-integrated zinc-silica core-shell Janus nanoparticles with UV protection, strength enhancement, and self-cleaning properties, is proposed. Polyphenols were utilized as sustainable precursors for synthesizing zinc-polyphenol complexes, which were then encapsulated within a silica shell to form a core-shell structure. Furthermore, Janus particles were created by introducing a bifunctional layer with half amine/carboxylic acid and half methyl terminals, imparting reactive hydrophilic and hydrophobic properties. Janus-coated textiles and leather exhibited significant attenuation of harmful UV radiation, with water contact angle measurements confirming improved water repellency. The coexistence of natural phenols and bifunctional groups within a material bolstered textile strength, fostering superior adhesion and markedly enhancing wash durability. This eco-friendly approach, utilizing waste-derived materials, presents a promising solution for sustainable textile engineering with enhanced performance in UV protection and water resistance, thereby contributing to the advancement of green nanotechnology in textile applications.

Cu-alginate hydrogels in microfluidic systems: a sustainable catalytic approach for click chemistry

This work explores the innovative use of copper-alginate (Cu-alginate) hydrogels within microfluidic systems to catalyze dipolar cycloaddition reactions, emphasizing green chemistry principles and process intensification. Utilizing naturally occurring biopolymers, such as alginates, provides an environmentally friendly alternative to conventional catalyst supports due to their biocompatibility, biodegradability, and effective metal ion immobilization capabilities. The integration of these biopolymer-based catalysts into microfluidic devices allows for precise control over reaction conditions, leading to enhanced reaction kinetics and mass transfer efficiencies. Our results demonstrate that Cu-alginate hydrogels effectively catalyze the formation of 1,4-disubstituted 1,2,3-triazoles through [3 + 2] dipolar cycloaddition reactions with high regioselectivity and conversion. The microfluidic setup ensures rapid and efficient synthesis, surpassing traditional batch reaction methods in both reaction rate and environmental impact by reducing solvent usage and waste generation. Furthermore, the use of microfluidics contributes to the reproducibility and scalability of the synthesis process, important for industrial applications. The model-based design and its simulations have been employed to further understand and optimize the reaction system. Diffusion through the gel layer and catalytic reaction kinetics estimated from experimental data were included in the model, providing a theoretical foundation for a comprehensive process evaluation. This study not only advances the field of sustainable catalysis by demonstrating the practical utility of biopolymer-supported catalysts in microfluidic systems, but also sets the stage for further research into biopolymer applications in complex chemical syntheses.

New Insights into Materials for Pesticide and Other Agricultural Pollutant Remediation

The increase in the world population and the intensification of agricultural practices have resulted in the release of several contaminants into the environment, especially pesticides and heavy metals. This article reviews recent advances in using adsorbent and catalytic materials for environmental decontamination. Different materials, including clays, carbonaceous, metallic, polymeric, and hybrid materials, are evaluated for their effectiveness in pollutant removal. Adsorption is an effective technique due to its low cost, operational simplicity, and possibility of adsorbent regeneration. Catalytic processes, especially those using metallic nanoparticles, offer high efficiency in degrading complex pesticides. Combining these technologies can enhance the efficiency of remediation processes, promoting a more sustainable and practical approach to mitigate the impacts of pesticides and other agricultural pollutants on the environment. Therefore, this review article aims to present several types of materials used as adsorbents and catalysts for decontaminating ecosystems affected by agricultural pollutants. It discusses recent works in literature and future perspectives on using these materials in environmental remediation. Additionally, it explores the possibilities of using green chemistry principles in producing sustainable materials and using agro-industrial waste as precursors of new materials to remove contaminants from the environment.

3-(Sulfamic acid)-propyltriethoxysilane on biochar nanoparticles as a practical, biocompatible, recyclable and chemoselective nanocatalyst in organic reactions.

Recyclable and inexpensive catalysts, waste regeneration, use of available and safe solvents are important principles of green chemistry. Therefore, in this project, biochar nanoparticles (BNPs) were synthesized by the pyrolysis method from chicken manure. Then, 3-(sulfamic acid)-propyltriethoxysilane (SAPES) was immobilized on the surface of BNPs (SAPES@BNPs). The prepared catalyst (SAPES@BNPs) was used as a commercial, practical, biocompatible and reusable catalyst in the selective oxidation of sulfides to sulfoxides. Further, the catalytic application of SAPES@BNPs was explored in the multicomponent synthesis of tetrahydrobenzo[b]pyrans under mild and green conditions. BNPs were characterized using SEM, TGA and XRD techniques. SAPES@BNPs were characterized using SEM, FT-IR spectroscopy, WDX, EDS, TGA, and XRD techniques. Particle size distribution was obtained by histogram graph. SAPES@BNPs can be recovered and reused several times. The purity of the products was studied using NMR spectroscopy.

Evaluation of the Open-Ended Green Chemistry Generic Comparison (GC)2 Prompt for Probing Student Conceptions about the Greenness of a Chemical Reaction.

One key limitation for assessing student knowledge of green chemistry is the lack of readily available assessments capable of eliciting reliable and valid data. Therefore, in this study we sought to evaluate the ability of a previously reported open-ended prompt [J. Chem. Educ.2019, 96 ( (11), ), 2410-2419. DOI: 10.1021/acs.jchemed.9b00277] to probe student conceptions about the greenness of chemical reactions. Responses to this prompt, which we titled the Green Chemistry Generic Comparison (GC)2 prompt, were collected from students enrolled in organic chemistry I and II lecture and laboratory courses (N = 642) and from students enrolled in general chemistry II lecture courses (N = 272). This prompt was found to be sensitive for detecting gains in green chemistry knowledge in pre- and post- conditions. Furthermore, psychometric analysis revealed that, while addressing certain green chemistry principles was well within the students' ability range, other principles exceeded that range. These findings indicate that this prompt provides a rapid and effective method for both measuring student knowledge and eliciting student conceptions of the green chemistry principles.

Application of signal processing techniques for the spectroscopic analysis of dolutegravir and lamivudine: a comparative assessment and greenness appraisal

HIV treatment has greatly improved over the years, with the introduction of antiretroviral drugs that target the virus and suppress its replication. Dolutegravir and lamivudine are two such antiretroviral drugs that are commonly used in HIV treatment regimens. Herein, three spectrophotometric methods manipulating ratio spectra were developed for the simultaneous analysis of dolutegravir and lamivudine in their binary mixtures. These methods include mathematical processing stages like ratio difference method or signal processing approaches such as the first derivative of the ratio spectra, and continuous wavelet transform. The developed spectrophotometric methods exploit the characteristic spectral differences between dolutegravir and lamivudine in order to quantify them simultaneously. These methods have shown promising results in terms of sensitivity and selectivity as validated per the ICH guidelines. Moreover, these methods offer a straightforward and economical alternative to more intricate analytical methodologies like high-performance liquid chromatography. By incorporating the analytical eco-scale and AGREE for greenness evaluation of the proposed methods, we can further ensure that these techniques are effective and environmentally friendly, aligning with the principles of green chemistry. This evaluation will provide a comprehensive understanding of the environmental friendliness of these spectrophotometric methods in pharmaceutical analysis.

Photo- and Electrochemical Organic Transformations Involving Radical Pathway: A Retrospection of Our Green-Chemistry-Inspired Synthetic Endeavours

AbstractThis account summarises our recent efforts (2020 to mid-2024) in designing and developing a handful of promising organic transformations for accessing several diversely functionalized biologically relevant organic scaffolds by following the green-chemistry principles with a particular focus on the application of low-energy visible light and electrochemistry. Mechanistic studies of each of these reactions established the involvement of a radical pathway.1 Introduction2 Green-Inspired Organic Transformations2.1 Visible-Light-Driven Organic Synthesis2.1.1 Synthesis of Functionalized Dihydrofuro[3,2-c]chromenones2.1.2 Synthesis of Functionalized 2-(Aryl/alkylamino)-3-(aryl/alkylselanyl)naphthalene-1,4-diones and 2-(Arylamino)-3-(arylthio)naphthalene-1,4-diones2.1.3 Synthesis of Functionalized 6-(Arylthio/arylseleno)benzo[a]phenazin-5-ols2.1.4 Synthesis of Functionalized 3-(Alkyl/benzylthio)-4-hydroxy-2H-chromen-2-ones2.1.5 Synthesis of Functionalized 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxamides and 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates2.1.6 Synthesis of Functionalized 2-Hydroxyphenylated α-Ketoamides2.2 Electrochemical Organic Synthesis2.2.1 Synthesis of 3-Selenylated/Sulfenylated Derivatives of 2-Amino-1,4-naphthoquinones2.2.2 Synthesis of Functionalized 6-(Arylthio/Arylseleno)benzo[a]phenazin-5-ols2.2.3 Synthesis of Functionalized Alkyl 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates3 Conclusions

Photo- and Electrochemical Organic Transformations Involving Radical Pathway: A Retrospection of Our Green-Chemistry-Inspired Synthetic Endeavours

AbstractThis account summarises our recent efforts (2020 to mid-2024) in designing and developing a handful of promising organic transformations for accessing several diversely functionalized biologically relevant organic scaffolds by following the green-chemistry principles with a particular focus on the application of low-energy visible light and electrochemistry. Mechanistic studies of each of these reactions established the involvement of a radical pathway.1 Introduction2 Green-Inspired Organic Transformations2.1 Visible-Light-Driven Organic Synthesis2.1.1 Synthesis of Functionalized Dihydrofuro[3,2-c]chromenones2.1.2 Synthesis of Functionalized 2-(Aryl/alkylamino)-3-(aryl/alkylselanyl)naphthalene-1,4-diones and 2-(Arylamino)-3-(arylthio)naphthalene-1,4-diones2.1.3 Synthesis of Functionalized 6-(Arylthio/arylseleno)benzo[a]phenazin-5-ols2.1.4 Synthesis of Functionalized 3-(Alkyl/benzylthio)-4-hydroxy-2H-chromen-2-ones2.1.5 Synthesis of Functionalized 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxamides and 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates2.1.6 Synthesis of Functionalized 2-Hydroxyphenylated α-Ketoamides2.2 Electrochemical Organic Synthesis2.2.1 Synthesis of 3-Selenylated/Sulfenylated Derivatives of 2-Amino-1,4-naphthoquinones2.2.2 Synthesis of Functionalized 6-(Arylthio/Arylseleno)benzo[a]phenazin-5-ols2.2.3 Synthesis of Functionalized Alkyl 2-Hydroxy-3-oxo-2,3-dihydrobenzofuran-2-carboxylates3 Conclusions

Development and Application of a Lignin-Based Polyol for Sustainable Reactive Polyurethane Adhesives Synthesis.

In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.

Development and Application of a Lignin-Based Polyol for Sustainable Reactive Polyurethane Adhesives Synthesis

In response to the environmental impacts of conventional polyurethane adhesives derived from fossil fuels, this study introduces a sustainable alternative utilizing lignin-based polyols extracted from rice straw through a process developed at INESCOP. This research explores the partial substitution of traditional polyols with lignin-based equivalents in the synthesis of reactive hot melt polyurethane adhesives (HMPUR) for the footwear industry. The performance of these eco-friendly adhesives was rigorously assessed through Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), rheological analysis, and T-peel tests to ensure their compliance with relevant industry standards. Preliminary results demonstrate that lignin-based polyols can effectively replace a significant portion of fossil-derived polyols, maintaining essential adhesive properties and marking a significant step towards more sustainable adhesive solutions. This study not only highlights the potential of lignin in the realm of sustainable adhesive production but also emphasises the valorisation of agricultural by-products, thus aligning with the principles of green chemistry and sustainability objectives in the polymer industry.

The Impact of Lignin Biopolymer Sources, Isolation, and Size Reduction from the Macro- to Nanoscale on the Performances of Next-Generation Sunscreen.

In recent years, concerns about the harmful effects of synthetic UV filters on the environment have highlighted the need for natural sun blockers. Lignin, the most abundant aromatic renewable biopolymer on Earth, is a promising candidate for next-generation sunscreen due to its inherent UV absorbance and its green, biodegradable, and biocompatible properties. Lignin's limitations, such as its dark color and poor dispersity, can be overcome by reducing particle size to the nanoscale, enhancing UV protection and formulation. In this study, 100-200 nm lignin nanoparticles (LNPs) were prepared from various biomass by-products (hardwood, softwood, and herbaceous material) using an eco-friendly anti-solvent precipitation method. Pure lignin macroparticles (LMPs) were extracted from beech, spruce, and wheat straw using an ethanol-organosolv treatment and compared with sulfur-rich kraft lignin (KL). Sunscreen lotions made from these LMPs and LNPs at various concentrations demonstrated novel UV-shielding properties based on biomass source and particle size. The results showed that transitioning from the macro- to nanoscale increased the sun protection factor (SPF) by at least 2.5 times, with the best results improving the SPF from 7.5 to 42 for wheat straw LMPs and LNPs at 5 wt%. This study underscores lignin's potential in developing high-quality green sunscreens, aligning with green chemistry principles.

Green process prorogue by xylanase enzyme and cellulose-derived sulfonated graphene oxide-like reinforcement in xylose and furfural production from corncob biomass

In this study, a process following the principles of green chemistry was applied for effective agricultural by-product conversion into biochemicals. Corncob was synergistically pretreated with a mixture of hydrogen peroxide:glacial acetic acid (1:2:2wt/v/v) which was denoted as C-HPAC and then xylanase enzyme-assisted hydrolysis to obtain the highest xylose content of 1.99g with 66.41% separation efficiency at 50°C for 15h, and xylanase enzyme content of 0.4g/3g C-HPAC. Otherwise, the sulfonated graphene oxide-like structural material (EC-SGO) was synthesized through the sulfonation method using various concentrations of H2SO4 agent with EC-GO that was calcinated with the mixture of ferrocene and cellulose (1:1wt/wt) at 300°C for 30 min. The highest furfural yield was 76.63±2.23% under the conditions of 60mg EC-SGO catalyst, xylose concentration of 3g/L, and NaCl 0.05 mol/L, at 180°C in 60 min. Hence, the synergistic effect of NaCl and Brønsted acid sites (−SO3H) was confirmed through the XPS spectrum with an acid content of 0.6895 mmol/gcatalyst and depicted simultaneously a vital role through the proposal mechanism of converting xylose to furfural. The synthesized catalyst retains its stability for the multiple cycles of furfural production. Furthermore, this work has provided a route for the fractional separation of xylose and cellulose with assisted-enzymatic.

Synthesis of novel phenylalanine-coated copper nanoclusters for fluorescent probes to determine the interactions of cancer drugs with DNA

Abiraterone acetate (ATA) is an FDA-approved prodrug that exerts its effects by irreversibly inhibiting the enzymatic activities of 17α-hydroxylase and C17,20-lyase, which are responsible for testosterone production, particularly. Drug-DNA interaction studies are conducted using various methods. In this study, CuNCs were used as a fluorescent probe for the first time to investigate drug-DNA interactions. Additionally, a new synthesis was developed for copper nanoclusters coated with phenylalanine (Phe). Ascorbic acid served as the reducing agent, while Phe was used as a surface functionalizing and stabilizing agent. Phe/CuNCs were characterized using various techniques including TEM, DLS, XPS, UV-Vis spectroscopy, and fluorescence spectroscopy. Optimization studies were conducted for synthesis parameters such as ascorbic acid concentration, Phe concentration, incubation time, and incubation temperature. This new synthesis method offers various advantages such as easy synthesis procedure, short synthesis time, and compatibility with green chemistry principles. Phe/CuNCs were used as a fluorescent probe for ATA-DNA interactions. The binding constant (Ka) between ATA and DNA was calculated as 1.03 × 104. Furthermore, thermodynamic studies indicated that the effective forces involved in ATA-DNA interaction are Van der Waals and hydrogen bonding.

Feasibility of matrix solid-phase dispersion combined with HR-CS FAAS for determination of copper in milk-based infant foods

This study proposes, for the first time, the development of an analytical method using the matrix solid-phase dispersion (MSPD) for extraction of copper from infant formulas and milk-based foods for further determination using high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). MSPD parameters were investigated, and by employing a 0.25 g sample, 0.25 g of diatomaceous earth as a solid support, 1 mol/L HNO3 as the extraction solution, and 1 min of blending, higher agreements with reference values were obtained. The limit of detection of the method was 0.35 µg/g. Accuracy was assessed by comparing the results using the following methods: i) proposed method (MSPD/HR-CS FAAS); and ii) decomposition of samples by microwave-assisted digestion (MAD) and quantification by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS). The MSPD extracts were also quantified using HR-CS GFAAS. No significant difference was found between the results. The agreements ranged from 95 to 103 %, and no significant difference was observed between the results. Copper concentrations ranged from 0.40 to 3.8 μg g−1 using the proposed method, with relative standard deviations lower than 10 %. The proposed method proved to be efficient for the determination of copper in infant formulas and milk powder, offering advantages such quickness, simplicity, low cost, low energy consumption, reduced waste generation (due to the use of an aqueous extraction solution), utilization of materials from renewable sources (diatomaceous earth as a solid support), and minimized analyst exposure when compared to conventional sample preparation methods. These attributes align with the principles of Green Analytical Chemistry.

Alfalfa biomass as a green source for the synthesis of N,S-CDs via microwave treatment. Application as a nano sensor for nifuroxazide in formulations and gastric juice

BackgroundResearchers have investigated different techniques for synthesis of carbon dots. These techniques include Arc discharge, laser ablation, oxidation, water/solvothermal, and chemical vapor deposition. However, these techniques suffer from some limitations like the utilization of gaseous charged particles, high current, high temperature, potent oxidizing agents, non-environmentally friendly carbon sources, and the generation of uneven particle size. Therefore, there was a significant demand for the adoption of a new technology that combines the environmentally friendly aspects of both bio-based carbon sourcing and synthesis technique. ResultsMedicago sativa L (alfalfa)-derived N, S-CDs have been successfully synthesized via microwave irradiation. The N,S-CDs exhibit strong fluorescence (λex/em of 320/420 nm) with fluorescence quantum yield of 2.2 % and high-water solubility. The produced N,S-CDs were characterized using TEM, EDX, Zeta potential analysis, IR, UV–Visible, and fluorescence spectroscopy. The average diameter of the produced N, S-CDs was 4.01 ± 1.2 nm, and the Zeta potential was −24.5 ± 6.63 mv. The stability of the produced nano sensors was also confirmed over wide pH range, long time, and in presence of different ions. The synthesized N, S-CDs were employed to quantify the antibacterial drug, nifuroxazide (NFZ), by fluorescence quenching via inner filter effect mechanism. The method was linear with NFZ concentration ranging from 1.0 to 30.0 μM. LOD and LOQ were 0.16 and 0.49 μM, respectively. The method was applied to quantify NFZ in simulated gastric juice (SGJ) with % recovery 99.59 ± 1.4 in addition to pharmaceutical dosage forms with % recovery 98.75 ± 0.61 for Antinal Capsules® and 100.63 ± 1.54 for Antinal suspension®. The Method validation was performed in compliance with the criteria outlined by ICH. Significance and noveltyThe suggested approach primarily centers on the first-time use of alfalfa, an ecologically sustainable source of dopped-CDs, and a cost-effective synthesis technique via microwave irradiation, which is characterized by low energy consumption, minimized reaction time, and the ability to control the size of the produced CDs. This is in line with the growing global recognition of the implementation of green analytical chemistry principles.

Alfalfa biomass as a green source for the synthesis of N,S-CDs via microwave treatment. Application as a nano sensor for nifuroxazide in formulations and gastric juice

BackgroundResearchers have investigated different techniques for synthesis of carbon dots. These techniques include Arc discharge, laser ablation, oxidation, water/solvothermal, and chemical vapor deposition. However, these techniques suffer from some limitations like the utilization of gaseous charged particles, high current, high temperature, potent oxidizing agents, non-environmentally friendly carbon sources, and the generation of uneven particle size. Therefore, there was a significant demand for the adoption of a new technology that combines the environmentally friendly aspects of both bio-based carbon sourcing and synthesis technique. ResultsMedicago sativa L (alfalfa)-derived N, S-CDs have been successfully synthesized via microwave irradiation. The N,S-CDs exhibit strong fluorescence (λex/em of 320/420 nm) with fluorescence quantum yield of 2.2% and high-water solubility. The produced N,S-CDs were characterized using TEM, EDX, Zeta potential analysis, IR, UV-Visible, and fluorescence spectroscopy. The average diameter of the produced N, S-CDs was 4.01 ± 1.2 nm, and the Zeta potential was -24.5 ± 6.63 mv. The stability of the produced nano sensors was also confirmed over wide pH range, long time, and in presence of different ions. The synthesized N, S-CDs were employed to quantify the antibacterial drug, nifuroxazide (NFZ), by fluorescence quenching via inner filter effect mechanism. The method was linear with NFZ concentration ranging from 1.0 to 30.0 μM. LOD and LOQ were 0.16 and 0.49 μM, respectively. The method was applied to quantify NFZ in simulated gastric juice (SGJ) with % recovery 99.59 ± 1.4 in addition to pharmaceutical dosage forms with % recovery 98.75 ± 0.61 for Antinal Capsules® and 100.63 ± 1.54 for Antinal suspension®. The Method validation was performed in compliance with the criteria outlined by ICH. Significance and NoveltyThe suggested approach primarily centers on the first-time use of alfalfa, an ecologically sustainable source of dopped-CDs, and a cost-effective synthesis technique via microwave irradiation, which is characterized by low energy consumption, minimized reaction time, and the ability to control the size of the produced CDs. This is in line with the growing global recognition of the implementation of green analytical chemistry principles.

Innovative eco-friendly stability-indicating HPLC-PDA method for simultaneous determination of the emerging antiviral drugs against COVID-19 infection molnupiravir and favipiravir; degradation kinetic studies along with LC-MS based structure elucidation

The adoption of the principles of green chemistry in analytical procedures lowers the negative influence on both people and the environment, which presently has become the key goal. Additionally, the need for advanced analytical techniques for the simultaneous determination of antiviral combinations is highly recommended, one of those novel combinations that recently proved effective emerging antiviral drugs in the treatment of SARS-COV-2 is molnupiravir (MOL) and favipiravir (FAV). Therefore, the establishment of simple and precise stability-indicating HPLC-PDA method for their simultaneous determination is crucial for the probable co-formulation. The stability of MOL was studied along with FAV after forced degradation of both under different stress conditions Separation of MOL, FAV, and their corresponding degradation products was achieved by simple isocratic HPLC-PDA method using a mobile phase comprised of 25.0 mM phosphate buffer (pH 3.0 ± 0.05) − methanol (70:30, v/v) at flow rate 1.0 mL/min. A Zorbax C18 (250 × 4.6 mm, 5 μm; Agilent Technologies, USA) column was used for the separation of the components and the column oven was maintained at 30 °C, the selected wavelength for detection of both analytes and their degradation products was 230.0 nm. The method was linear over the range of 1.0 – 200.0 µg/mL for both MOL and FAV. MOL was found to be susceptible to all forced degradation conditions, namely, acid, alkali, oxidative, thermal, and photodegradation while FAV was susceptible only to acid, alkali, and oxidative degradation. The probable degradation mechanisms were assumed through the evaluation of the MS1 fragmentation pattern of the degradation products, also studying the kinetic behavior of the degradation reactions. Furthermore, the greenness profile for the proposed method was evaluated utilizing the new Complementary Green Analytical Procedure Index method (ComplexGAPI), and analytical greenness (AGREE) metrics with a score of the later one equals to 0.61 that indicated the greenness evaluation of the method. In addition, the new blue applicability grade index (BAGI) which is complementary to the green metrics showed a score of 85.0 that presents a good applicability potential of the method. The proposed method is the first sustainable, stability-indicating method developed for the simultaneous determination of this potential combination that would help in manufacturing both drugs in a fixed-dose drug combination.