Green Chemistry Research Articles

Advancing training for green and sustainable chemistry

Advancing training for green and sustainable chemistry

The effectiveness of natural indigo/kaolinite composite powder in the development of latent fingermarks

BackgroundComposites are materials that have multiple phases and have attracted much attention as they are able to improve physical and chemical properties of an isolated material. In this sense, these composites are commonly used as key components for two purposes: coloring and improving the operational properties; besides that, they have alternative synthesis routes that respect the principles of green chemistry. Thus, this reports the development of a new composite using natural products, indigo and kaolinite, for application in papilloscopy as a new nontoxic fingermark developer.ResultsThe composite was obtained via green procedures and was characterized by spectroscopic and chromatographic techniques. Thus, to investigate the potential of the material as a fingermark developer, different techniques were applied such as depletion, aging, comparison with commercial powder, and development of latent fingermarks on different surfaces. Tests revealed that the composite presented good contrast and adhesion with the latent fingermarks, even after 15 days of deposition.ConclusionsThis study presents a natural indigo/kaolinite composite powder that showed similar or higher efficiency when compared to the commercial fingerprint powder and was able to develop identifiable natural and sebaceous fingermarks.Key points• A composite was formed from eco-friendly materials.• The composite formation follows the concepts of green chemistry and low cost.•The composite was applied as a latent fingermark developer.

The past is the future: from natural acid-base indicators to natural reagents in sustainable analytical chemistry

Abstract This article reviews the use of natural resources in analytical chemistry throughout history. Plant extracts were employed as indicators in chemistry for identifying the acidity or alkalinity of liquids as early as the 1650s. Later, as the industrial revolution altered people’s lives, synthetic chemicals were used instead. Modern techniques of analysis have replaced conventional ones as a result of advancements in physics and technology. The industrial revolution was an era of excitement until the toxic pollutants released from industries severely damaged people and the environment. The concepts of green chemistry and green analytical chemistry were proposed as potential solutions to the problems. The use of natural extracts as chemical analysis reagents has been reconsidered recently as a sustainable alternative. While new technologies such as artificial intelligence (AI) will influence future trends in analytical chemistry development, the primary goal is to move toward sustainable analytical chemistry, which includes using natural reagents and reducing the amount of chemicals consumed and waste produced.

Automated H2O2 monitoring during photo-Fenton processes using an Arduino self-assembled automatic system

A cheap and easy to use Arduino self-assembled automatic system was employed to continuously monitor the hydrogen peroxide consumption during the photo-Fenton degradation of caffeine, selected as model target compound. The automatic system made it possible to measure the H2O2 concentration in the reaction cell via a colorimetric reaction and to take samples for HPLC analysis minimising the operator manual intervention and exposure to UV radiation. The obtained results were compared in terms of LOD and LOQ with H2O2 measurements manually performed using UV-Vis spectrophotometry, evidencing better analytical performance when using the automatic system; LOD and LOQ were respectively 0.032mM and 0.106mM for the automatic system against 0.064mM and 0.213mM for UV-Vis spectrophotometry. Furthermore, the photo-Fenton treatment was optimised by means of a Design of Experiments (DoE) investigating the effect of added H2O2 concentration, iron concentration and caffeine initial concentration on system performances. The use of the automatic device for such monitoring provided several advantages: automation (with consequent reduction of the workload), measurement increased precision, reduced reagents consumption and waste production in agreement with the principles of Green Analytical Chemistry.

Novel Catechol O-methyltransferases from Lentinula edodes Catalyze the Generation of Taste-Active Flavonoids.

Due to the increasing demand for natural food ingredients, including taste-active compounds, enzyme-catalyzed conversions of natural substrates, such as flavonoids, are promising tools to align with the principles of Green Chemistry. In this study, a novel O-methyltransferase activity was identified in the mycelium of Lentinula edodes, which was successfully applied to generate the taste-active flavonoids hesperetin, hesperetin dihydrochalcone, homoeriodictyol, and homoeriodictyol dihydrochalcone. Furthermore, the mycelium-mediated OMT activity allowed for the conversion of various catecholic substrates, yielding their respective (iso-)vanilloids, while monohydroxylated compounds were not converted. By means of a bottom-up proteomics approach, three putative O-methyltransferases were identified, and subsequently, synthetic, codon-optimized genes were heterologously expressed in Escherichia coli. The purified enzymes confirmed the biocatalytic O-methylation activity against targeted flavonoids containing catechol motifs.

Carbon-Supported Ru-Ni and Ru-W Catalysts for the Transformation of Hydroxyacetone and Saccharides into Glycol-Derived Primary Amines.

Nitrogen-containing molecules are used for the synthesis of polymers, surfactants, agrochemicals, and dyes. In the context of green chemistry, it is important to form such compounds from bioresource. Short-chain primary amines are of interest for the polymer industry, like 2-aminopropanol, 1-aminopropan-2-ol, and 1,2-diaminopropane. These amines can be formed through the amination of oxygenated substrates, preferably in aqueous phase. This is possible with heterogeneous catalysts, however, effective systems that allow reactions under mild conditions are lacking. We report an efficient catalyst Ru-Ni/AC for the reductive amination of hydroxyacetone into 2-aminopropanol. The catalyst has been reused during 3 cycles demonstrating a good stability. As a prospective study, extension to the reactivity of (poly)carbohydrates has been realized. Despite a lesser efficiency, 2-aminopropanol (9 % yield of amines) has been formed from fructose, the first example from a carbohydrate. This was possible using a 7.5 %Ru-36 %WxC/AC catalyst, composition allowing a one-pot retro-aldol cleavage into hydroxyacetone and reductive amination. The transformation of cellulose through sequential reactions with a combination of 30 %W2C/AC and 7.5 %Ru-36 %WxC/AC system gave 2 % of 2-aminopropanol, corresponding to the first example of the formation of this amine from cellulose with heterogeneous catalysts.

Design of Experiments for Optimized Synthesis of Carbon‐Supported Ni Nanoparticles: A Green Chemistry Approach

AbstractMetallic nickel nanoparticles supported on a high specific surface area carbon powder were synthesized by a classical polyol method without external reducing agent or surfactant. Ni/C materials were characterized by TGA, XRD, cyclic and linear voltammetry. To decrease the number of experiments, a Taguchi design of experiments (DoE) was implemented and the effects of different synthesis parameters (nature of the nickel salt, loading of Ni on carbon, nNaOH/nNi ratio and reaction time at reflux) on different responses (crystallite size, electrochemically active surface area and current density for the glucose oxidation reaction at 1.5 V) determined. Optimization of parameter values for decreasing the crystallite size down to 14 nm was achieved using the DoE. For the other responses, strong interactions between parameters avoided straightforward optimization of parameter values. However, some trends could be drawn from the experimental matrix showing that the synthesis of a catalyst loaded with only 10 wt% Ni, with NiCl2 as precursor salt, with a nNaOH/nNi ratio of 6 for 80 minutes at reflux was a good compromise between atom, time and energy savings, costs efficiencies, and electrochemically active surface area and catalytic activity towards the glucose oxidation reaction, particularly in terms of mass activity.

Millistructured Coiled Flow Inverter for Biphasic Continuous Flow 5‐Chloromethylfurfural Synthesis

AbstractSyntheses of alternative platform chemicals, such as 5‐chloromethylfurfural (CMF), from bio‐based starting materials are often associated with complicated kinetic schemes and mass transfer processes. Millistructured flow reactor concepts can help to elucidate kinetic schemes and determine rate constants which are of crucial importance for the design of respective technical processes. For the first time, the influence of proton concentration on the rate constants involved in the biphasic synthesis of CMF is systematically investigated. Results are discussed in terms of green chemistry metrics.

Ultrasound-assisted extraction of major anthocyanins in Korean black raspberries (Rubus coreanus Miquel) using natural deep eutectic solvents

This study investigated a methodology for the extraction of major anthocyanin from Korean black raspberries (KBR) using green chemistry. Ternary natural deep eutectic solvent (NADES) used in this study consisted of choline chloride, malic acid, and 1,4-butanediol (2:1:1; w/w/w) based on the viscosity and total anthocyanin contents. The interaction between the components of ternary NADES and their characteristic functional groups were confirmed from infrared spectroscopy. The optimized extraction conditions based on the Box–Behnken design and response surface methodology were as follows: extraction temperature of 26.6 °C, extraction time of 15.2 min, and NADESs water content of 23.3% (v/v). The efficient extraction efficiency and storage stability of cyanidin-3-O-glucoside (C3G) in the ternary NADES were determined. The extraction efficiency of C3G from KBR was most influenced by the water content of the NADES. The storage stability of C3G extracted from KBR using the ultrasound-assisted method with optimized ternary NADES was higher than pure water and acidic water (0.1M HCl). C3G from KBR in the NADES remained stable at > 97% for nine days. The proposed methodology adheres to green chemistry principles, emphasizing on low energy consumption, mild conditions, biodegradability, and eco-friendliness.

Hypothesizing the Green Synthesis of Tamoxifen Loaded Magnetic Nanoparticles for the Treatment of Breast Cancer.

Breast cancer is the second leading cause of death all over the world and is not only limited to females but also affects males. For estrogen receptor-positive breast cancer, tamoxifen has been considered the gold-line therapy for many decades. However, due to the side effects associated with the use of tamoxifen, its use is only limited to individuals in high-risk groups and limits its clinical application to moderate and/or lower-risk groups. Thus, there is a necessity to decrease the dose of tamoxifen, which can be achieved by targeting the drug to breast cancer cells and limiting its absorption to other body parts. Artificial antioxidants used in the formulation preparation are assumed to upsurge the risk of cancer and liver damage in humans. The need of the hour is to explore bio-efficient antioxidants from natural plant sources as they are safer and additionally possess antiviral, anti-inflammatory, and anticancer properties. Objectives of the study and research: The objective of this hypothesis is to prepare tamoxifen-loaded PEGylated NiO nanoparticles using green chemistry, tumbling the toxic effects of the conventional method of synthesis for targeted delivery to breast cancer cells. Significance of the research work: The significance of the work is to hypothesize a green method for the synthesis of NiO nanoparticles that are eco-friendly, cost-effective, decrease multidrug resistance, and can be used for targeted therapy. Garlic extract contains an organosulfur compound (Allicin) which has drug-metabolizing, anti-oxidant, and tumour growth inhibition effects. In breast cancer, allicin sensitizes estrogen receptors, increasing the anticancer efficacy of tamoxifen and reducing offsite toxicity. Thus, this garlic extract would act as a reducing agent and a capping agent. The use of nickel salt can help in targeted delivery to breast cancer cells and, in turn, reduces drug toxicity in different organs. Future directions/recommendations: This novel strategy may aim for cancer management with less toxic agents acting as an apt therapeutic modality.

Search for new green natural solid phases for sample preparation for PAHs determination in seafood samples followed by LC and GC–MS/MS analysis

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic organic pollutants found in various environments, notably aquatic ecosystems and the food chain, posing significant health risks. Traditional methods for detecting PAHs in food involve complex processes and considerable reagent usage, raising environmental concerns. This study explores eco-friendly approaches suing solid phases derived from natural sources in matrix solid phase dispersion. We aimed to develop, optimize, and validate a sample preparation technique for seafood, employing natural materials for PAH analysis. Ten natural phases were compared with a commercial reference phase. The methodology involved matrix solid phase dispersion and pressurized liquid extraction, followed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Three solid phases (perlite, sweet manioc starch, and barley) showed superior performance in LC-MS/MS and were further evaluated with gas chromatography-tandem mass spectrometry (GC–Ms/MS), confirming perlite as the most effective phase. Validation followed Brazilian regulatory guidelines and European Community Regulation 2021/808/EC. The resulting method offered advantages in cost-effectiveness, reduced environmental impact, cleaner extracts, and enhanced analytical performance compared to the reference solid phase and LC-MS/MS. Proficiency analysis confirmed method reliability, with over 50% alignment with green analytical chemistry principles. In conclusion, this study developed an environmentally sustainable sample preparation technique for seafood analysis using natural solid phases, particularly perlite, for PAH determination.

Green Analytical Chemistry to Eco-Friendly HPLC Techniques in Pharmaceutical Analysis: A Review

Green Analytical Chemistry to Eco-Friendly HPLC Techniques in Pharmaceutical Analysis: A Review

Design of molecularly imprinted polymers (MIP) using computational methods: A review of strategies and approaches

AbstractThis paper focuses on the computationally assisted design of molecularly imprinted polymers (MIP), emphasizing the selected strategies and chosen methods of approach. In summary, this paper provides an overview of the MIP fabrication procedure, focusing on key factors and challenges, where the fabrication of MIP includes a step‐by‐step process with extensive experimental procedures. This brings challenges in optimizing experimental conditions, such as the selection of monomer, cross‐linker, and their relevant molar ratios to the template and solvent. Next, the principles of computational methods are elucidated to explore their potential applicability in solving the challenges. The computational approach can tackle the problems and optimize the MIP's design. Finally, the atomistic, quantum mechanical (QM), and combined methods in the recent research studies are overviewed with stress on strategies, analyses, and results. It is demonstrated that optimization of pre‐polymerization mixture by employing simulations significantly reduces the trial‐and‐error experiments. Besides, higher selectivity and sensitivity of MIP are observed. The polymerization and resulting binding sites by computational methods are considered. Several models of binding sites are formed and analyzed to assess the affinities representing the sensitivity and selectivity of modeled cavities. Combined QM/atomistic methods showed more flexibility and versatility for realistic modeling with higher accuracy. This methodological advancement aligns with the principles of green chemistry, offering cost‐effective and time‐efficient solutions in MIP design.This article is categorized under: Structure and Mechanism > Molecular Structures Structure and Mechanism > Computational Materials Science Molecular and Statistical Mechanics > Molecular Interactions

An ingenious technique based on the usage of fluorone-based dye; pyrosin B in prucalopride assay in different matrices through an "on-off" dye native fluorescence probe.

Prucalopride (PCD), is a modern medication approved by the United States in 2018 to alleviate constipation caused by motility issues. PCD demonstrates a strong affinity and selectivity toward the 5-HT4 receptor. The study here introduces a feasible, direct, non-extractive, and affordable pathway for PCD analytical tracking. The fluorimetric study is based on the on-off effect on the emission amplitude of fluorone-based dye (pyrosin B). In a one-pot experiment, the complex between PCD and pyrosin B is formed instantly in an acidic medium. Correlation between decreased pyrosin B emission and PCD concentrations provides a linear calibration plot from 50 to 900 ng/mL. PCD-dye complex system affecting variables were meticulously tuned. The values of the estimated limit of quantitation and limit of detection for the current methodology were 47.5 and 15.7ng/mL, respectively. Conformity of the strategy validity was achieved by a comprehensive study of the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use criteria. The method was convincingly applied for PCD assay in tablets and content uniformity investigation. Furthermore, PCD tracking in the spiked biological fluid was applied. Finally, the method uses distilled water as dispersing medium which rise accommodation with the green chemistry principle.

Aqueous CuS nanocrystals via a flow synthesis approach

Aqueous CuS nanocrystals via a flow synthesis approach

Butea monosperma aided green synthesis of α-MoO3 nanoparticles: Biosensing and photocatalytic activity towards hazardous dyes and rangoli colorants

Increasing environmental pollutants and the need for efficient photocatalytic and biosensing materials have led to the development of novel green synthesis methods. In this study, MoO3 nanoparticles (NPs) were successfully synthesized by using green chemistry approach. In that respect, Butea monosperma leaf powder was used as a novel fuel. Structural parameters, optical properties, shape and morphology of MoO3 NPs are examined using XRD, FTIR, UV–Vis spectrophotometer, Photoluminescence (PL), SEM - EDAX and TEM analysis. The use of MoO3 NPs as a dusting agent in fingerprint applications results in improved fingerprint visibility, which is useful in forensic investigation. In this study, we modified the GCE electrode surface with MoO3 NPs to develop a highly sensitive dopamine (DA) sensor. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) were used to investigate the electrochemical behaviour and electrocatalytic property of the MoO3 NPs. The synthesized NPs have excellent performance for detection of highly sensitive biologically active DA. The sensor exhibits a low detection limit of 0.45 μM. Additionally, it shows good stability, simplicity, and selectivity for the rapid detection of DA. MoO3 NPs shows good photocatalytic activity under UV light for the degradation of important textile industries dye such as methylene blue (MB) and harmful rangoli colors which are available in local shops of Tumkur, Karnataka. The photocatalyst exhibits a remarkable 97 % degradation efficiency for MB dye. Coumarin studies ensure the effective generation of OH radicals on the surface of the photocatalyst, leading to the degradation of organic dyes. Additionally, the MoO3 NPs reusability was examined, and even after four cycles, the level of photocatalytic activity did not drop much. Therefore, it is a potential photocatalyst for the processing of organic colours.

Synthesis of lithium and silver nanoparticles by green chemistry and its antimicrobial effect on Staphylococcus aureus and Klebsiella pneumoniae

Synthesis of lithium and silver nanoparticles by green chemistry and its antimicrobial effect on Staphylococcus aureus and Klebsiella pneumoniae. The synthesis of NPs (nanoparticles) using lithium and silver salts and its characterization by scanning electron microscopy (SEM) was carried out. The effect of silver (AgNPs) and Lithium (LiNPs) nanoparticles (NPs) on the proliferation of Staphylococcus aureus and Klebsiella pneumoniae, was evaluated. For all concentrations evaluated, inhibition of bacterial growth was observed with a MIC close to 0.8 mg/mL-AgNPs and 0.6 mg/mL-LiNPs against S. aureus and 1 mg/mL- AgNPs and 0.6 mg/mL- LiNPs against K. pneumonia. Given the actual development of bacterial resistance to antibiotics, we contributed with an alternative for the future treatment of bacterial infections in humans and animals by evaluation of activities of synthetic metallic nanoparticles.

Magnetite nanoparticles (Fe3O4 NPs) performed by the co-precipitation and green synthesis processes

Abstract The design of chemical processes and products with a low use of hazardous substances is known as “green chemistry.” The method of producing nanoparticles (NPs) significantly affects their size and characteristics. Currently, there are two primary methods utilized for synthesizing NPs, known as the bottom-up and top-down approaches. To keep the prices of nanotechnology-based products, the green method employs plant metabolites as reducing agents. Two types of magnetite NPs (Fe3O4 NPs) were synthetized and characterized being denominated NPs1 synthetized by the co-precipitation method and NPs2 synthetized using the green synthesis process. It was found that the Fe3O4 NPs1 has a quasi-spherical morphology with a size of 43 nm, while the Fe3O4 NPs2 has a size of 6 nm.

Heterogenization of [Ru(bpy)3].Cl2 on ordered mesoporous silica materials for photocatalytic applications

Herein, the preparation and characterization of three Ru-based heterogeneous photocatalysts supported on ordered mesoporous silica materials are reported. The photocatalytic activity of these catalysts was evaluated through oxidation, reduction, cycloaddition and carboxylation reactions and their efficiencies are comparable to the parent [Ru(bpy)3]Cl2 in homogeneous conditions. These photocatalysts are efficiently recovered even after five reactions cycles offering new opportunities in sustainable chemistry

A greener RP-HPLC method for quaternary estimation of caffeine, paracetamol, levocetirizine, and phenylephrine acquiring AQbD with stability studies

Abstract The main objective of this article was to develop method and validate quaternary estimation of caffeine (CFE), paracetamol (PCM), levocetirizine (LEV), and phenylephrine (PHE) and to conduct degradation experiments using reverse-phase high-performance liquid chromatography (RP-HPLC). This was the first innovative approach to this drug combination, combining analytical quality by design with green analytical chemistry. This method was developed using HPLC Agilent 1220 Infinity II, a binary solvent delivery pump, an automatic sampling device injector, and a photodiode array detector. Agilent Inertsil ODS 3 (250 mm × 4.6 mm, 5 μm) was used for separation. The mobile phase is composed of ethanol and 10 mM phosphate buffer (pH 3). To adjust the pH, 1% of orthophosphoric acid was used. The flow rate was set to 0.8 ml·min−1, the injection volume was 10 μl, and the detecting wavelength was 220 nm. The analytes were eluted via gradient elution. The retention time for PCM was 3.5 min, CFE was 8.1 min, PHE was 15.9 min, and LEV was 20.5 min. Green evaluation tools used in this research include Green Analytical Procedure Index, analytical eco-scale, analytical greenness, analytical method greenness score, and carbon footprint analysis. The developed method was greener than the previously reported method, as per the results of the greenness evaluation tools.