Green Samples Research Articles

Nanoarchitecturing of Mo2C nanospheres on carbon cloth as an electrochemical sensing platform for determination of caffeic acid in tea samples

In the present paper, carbon cloth (CC) as a flexible substrate was modified by molybdenum carbide nanospheres (Mo2C NSs @CC) by the drop-coating method to develop a sensitive electrochemical platform for detecting caffeic acid. The uniform Mo2C NSs were prepared via an easy route followed by pyrolyzing the precursor of the Mo-polydopamine (Mo-PDA) NSs. The Mo2C NSs were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), Raman spectroscopy (RS), and electrochemical methods. CC not only gave a flexible feature to the sensor but also provided a larger surface area for Mo2C NSs. Meanwhile, the excellent conductivity and large electroactive specific surface area of Mo2C NSs exhibited excellent electrocatalytic performance for caffeic acid determination. The developed sensor showed high sensitivity and selectivity, good reproducibility, and long-term stability with a limit of detection (LOD) and a wide linear range of 0.001 μM (S/N = 3) and 0.01–50 μM, respectively. In addition, the Mo2C NSs @CC sensor showed a promising application prospect for the detection of caffeic acid in green and black tea samples, indicating its importance in food safety and the food industry.

Experimental Research on Green Concrete

Concrete is a predominant material in global construction due to its versatility and essential role in various infrastructure projects. However, its production is responsible for approximately 8 to 10 % of global CO2 emissions, primarily attributed to the manufacturing of cement. Consequently, there is a critical need to reduce concrete usage and seek eco-friendly alternatives to conventional cement. Green concrete refers to concrete produced by incorporating waste materials such as fly ash, slag, by-products from power plants, recycled concrete aggregate, and waste glass, this approach aims to reduce carbon dioxide emissions associated with traditional concrete production. This study presents experimental work conducted on both conventional and green concrete samples of M40 mix design. The green concrete samples incorporated fly ash as a partial replacement for cement at 20%, 25%, and 30% levels, and used recycled concrete aggregate (RCA) to replace 50% of both fine and coarse aggregates. The primary objectives were to design a concrete mix that maintains properties comparable to conventional concrete, reduces environmental impact by substituting waste materials for cement, and achieves cost efficiency.

The Light-Intensity-Affected Aroma Components of Green Tea during Leaf Spreading.

Leaf spreading is a key processing step that affects the aroma formation of green tea. The effects of a single-light wavelength on the aroma and taste of tea have been extensively studied. Less attention has been paid to the effect of different complex light intensities on the formation of green tea's volatile aroma during leaf spreading. The current study was designed to evaluate how leaf spreading under different complex light intensities relates to the quality of green tea. Using headspace solid-phase micro-extraction and gas chromatography-mass spectrometry (HS-SPME/GC-MS), volatile flavor compounds in green tea were analyzed during leaf spreading in five different light conditions. Multivariate statistical analysis and odor activity values (OAVs) were used to classify these samples and identify key odors. Eight distinct groups, including ninety volatile compounds, were detected. The most prevalent volatile compounds found in green tea samples were hydrocarbons and alcohols, which accounted for 29% and 22% of the total volatile compounds, respectively. Fourteen volatile compounds (OAV > 1) were identified as key active differential odorants. The chestnut-like aroma in green tea was mostly derived from 3-methyl-butanal and linalool, which were significantly accumulated in medium-intensity light (ML).

Construction of an efficient molecular enrichment and magnetic separation flow with Fe3O4@Ag@COF for ratiometric SERS detection of methamidophos

As a typical organophosphorus pesticide widely utilized in agricultural production with its residue as enormous threat to human health and environment, methamidophos (MTD) has gained increasing attention in recent years, so, it is necessary to develop an effective strategy to detect MTD from complex matrix. Here, an efficient molecular enrichment and magnetic separation flow was constructed through Fe3O4@Ag@COF (covalent organic framework) for ratiometric SERS detection of MTD. Specifically, Fe3O4@Ag@COF is shown to have a high-density hot-spot region and optimal SERS performance by adjusting the particle size and addition volume of Fe3O4@Ag. COF endows Fe3O4@Ag@COF with a platform for enriching MTD molecules and isolating impurities, allowing the separation of Fe3O4@Ag@COF with MTD molecules from complex matrix by magnetism. More importantly, due to its natural core–shell structure, the Raman peaks of COF can be employed as an internal standard for ratiometric SERS sensing, thereby increasing its analysis accuracy and reliability. Under the optimal extraction method and solvent conditions, the developed detection flow exhibited a wide linear range from 10-4 M to 10-9 M and a low MTD detection limit of 8.3 × 10-5 mg/kg. Furthermore, the SERS sensor had excellent reproducibility and long-term stability with a low relative standard deviation (RSD). In practical application, this detection flow was tested for quantifying trace MTD in green tea samples, with recoveries of 89.54 % to 101.89 % and RSDs below 5 % (n = 5), comparable to the performance of gas chromatography mass spectrometry (GC–MS).

Automated green sample preparation for quantitative extraction of lipids in different sample matrices

An essential step in all analytical workflows is the quantitative and robust extraction of the molecules of interest. While typical lipid extractions use hazardous solvents from non-renewable sources, in this work, an extraction protocol utilizing green solvents such as ethanol and ethyl acetate is presented. The workflow was also automated to reduce variability and increase robustness as well as sample throughput. Moreover, this minimizes the contamination risks and lowers the operator's exposure to organic solvents. The developed workflow was critically evaluated by the recovery of various lipid standards from different matrices (human plasma, human serum, HepG2 cells) yielding quantitative values around 80–90 % for most lipid classes. The investigation into concentration dependency reveals the robustness of the method, demonstrating consistent recoveries across various lipid concentrations and matrix contents. In non-targeted lipidomics analyses, the green solvents proved to be comparable to established protocols that use conventional solvents such as methyl‑tert-butylether (MTBE) for lipid extraction.

Green synthesis of gadolinium-doped bismuth oxide nanoparticles: Exploring their biological and photocatalytic activities

Coldeniaprocumbens leaf extract assisted green synthesis of gadolinium-doped bismuth oxide nanoparticles (Gd-Bi2O3NPs) was demonstrated. Electron microscopic analysis indicated that the Gd-Bi2O3 has nanoflake-like shape with a narrow size distribution of 20–30 nm. FT-IR and XRD analysis confirmed the doping of Gd-ions into Bi2O3 crystal structure. The UV–vis spectral investigation was carried to know the characteristic absorbance peaks and the band gap of Gd-Bi2O3 samples. The antibacterial activity of Gd-Bi2O3 samples was evaluated against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Enterococcus faecalis. The larvicidal activity of Gd-Bi2O3 samples was also evaluated against the mosquito larvae of Aedesaegypti and Aedesalbopictus. Furthermore, the photocatalytic potential of Gd-Bi2O3 samples has been evaluated using malachite green (MG) and methylene blue (MB) dyes under visible light radiation. The green Gd-Bi2O3 samples displayed potent antibacterial, larvicidal, and photocatalytic activities, making them a promising candidate for environmental remediation applications.

Evaluation of the ecological risks on green macro-algae spp. (Ulva fusciata) at the north western coast of Egypt, using neutron activation technique

The study used the radio-analytical technique (Neutron Activation Analysis), besides the other advanced chemical technique, which was inductively coupled plasma mass spectroscopy (ICP-MS), in order to evaluate the bioaccumulation factor (BF), of different trace elements inside the collected green macro algal samples. The results showed that BF results were based on the algal selectivity of each analyzed trace element. The study recommended the using of Ulva fasciata, as a bio-filter of nuclear cooling water system (mitigation tool), due to its selective absorption ability for certain trace elements such as; Th, Cs &Sr.

Optimization of Green Sample Preparation for the Determination of Hydroxycinnamic Acids in Multi-Floral Honey Using Response Surface Methodology

Hydroxycinnamic acids are an essential phenolic group in honey that are related with its diverse health effects. Furthermore, they can be considered as potential biomarkers for botanical and geographical origin. The extraction of hydroxycinnamic acids from honey requires complicated extraction techniques due to their low contents and matrix particularity. The goal of the present work was to develop a green sample preparation method for the solubilization of hydroxycinnamic acids in honey samples. Thus, a Box–Behnken design has been used to investigate the effect of four factors: (i) percentage of ethanol (60–90%, v/v), (ii) temperature (30–60 °C), (iii) solvent-honey ratio (10–30 mL g−1), and (iv) sonication time (10–40 min) on the contents of caffeic, chlorogenic, and ferulic acids. Based on the desirability index, the ultrasound-assisted mixing of honey with 60.0% (v/v) ethanol at a solvent-honey ratio of 10 mL g−1 for a period of 17.8 min at a temperature of 54.6 °C resulted in the maximum solubilization of hydroxycinnamates. Subsequently, the greenness of developed method was assessed and applied successfully on the analysis of honeys. The present study reports for first time the hydroxycinnamic acid fingerprint of multi-floral honey produced in Cyprus.

A Novel Green Sample Pretreatment Method Column-Free Matrix Solid-Phase Dispersion Extraction: Application in a High-Performance Liquid Chromatography Experiment for Undergraduate Chemistry

A Novel Green Sample Pretreatment Method Column-Free Matrix Solid-Phase Dispersion Extraction: Application in a High-Performance Liquid Chromatography Experiment for Undergraduate Chemistry

Pesticide application behavior in green tea cultivation and risk assessment of tea products: a case study of Rizhao green tea.

Previous research on pesticides in green tea mainly focused on detection technology but lacked insights into pesticide use during cultivation. To address this gap, a survey was conducted among Rizhao green tea farmers. The survey results showed that most tea farmers were approximately 60years old and managed small, scattered tea gardens (< 0.067ha). Notably, tea farmers who had received agricultural training executed more standardized pesticide application practices. Matrine and thiazinone are the most used pesticides. A total of 16 types of pesticides were detected in the tested green tea samples, with 65% of the samples containing residues of at least one pesticide. Notably, higher levels of residues were observed for bifenthrin, cyfluthrin, and acetamiprid. The presence of pesticide residues varied significantly between seasons and regions. The risk assessment results indicated that the hazard quotient (HQ) values for all 16 pesticides detected in green tea were < 1, suggesting that these residue levels do not pose a significant public health concern.

High throughput compressive fluorescence lifetime imaging with a silicon photomultiplier detector.

Fluorescence lifetime imaging microscopy (FLIM) is a powerful technique for studying biological processes. There exists a growing interest in developing strategies to enhance throughput and reduce acquisition time of FLIM systems, which commonly employ laser scanning excitation and time-correlated single-photon counting (TCSPC) detection. In this work, we propose a wide-field FLIM microscope based on compressive sensing and high photon rate detection (beyond pile-up limit) based on a high-efficiency silicon photomultiplier detector as a single-pixel camera. We experimentally validate the capabilities of this design achieving 20 frames per second FLIM images on free-moving green algae sample.

Rapid and Online Microvolume Flow-Through Dialysis Probe for Sample Preparation in Veterinary Drug Residue Analysis.

A rapid and online microvolume flow-through dialysis probe designed for sample preparation in the analysis of veterinary drug residues is introduced. This study addresses the need for efficient and green sample preparation methods that reduce chemical waste and reagent use. The dialysis probe integrates with liquid chromatography and mass spectrometry (LC-MS) systems, facilitating automated, high-throughput analysis. The dialysis method utilizes minimal reagent volumes per sample, significantly reducing the generation of solvent waste compared to traditional sample preparation techniques. Several veterinary drugs were spiked into tissue homogenates and analyzed to validate the probe's efficacy. A diagnostic sensitivity of >97% and specificity of >95% were obtained for this performance evaluation. The results demonstrated the effective removal of cellular debris and particulates, ensuring sample integrity and preventing instrument clogging. The automated dialysis probe yielded recovery rates between 27 and 77% for multiple analytes, confirming its potential to streamline veterinary drug residue analysis, while adhering to green chemistry principles. The approach highlights substantial improvements in both environmental impact and operational efficiency, presenting a viable alternative to conventional sample preparation methods in regulatory and research applications.

GC-MS Combined with Proteomic Analysis of Volatile Compounds and Formation Mechanisms in Green Teas with Different Aroma Types.

Aroma is one of the key factors for evaluating the quality of green tea. A tender aroma (NX) and floral-like aroma (HX) are two types of high-quality aroma of green tea. In this work, the different aroma types of baked green tea were classified by sensory evaluation. Then, seven tea samples with a typical tender or floral-like aroma were selected for further volatile component analysis by GC-MS. A total of 43 aroma compounds were identified in two different aroma types of baked green tea samples. The PCA showed that linalool, geraniol, 3-hexenyl butyrate, and 3-hexenyl hexanoate were the major volatiles contributing to the HX. On the other hand, most of the alcohol volatiles, such as 1-octanol, 1-octen-3-ol, 1-dodecanol, 1-hexadecanol, phenylethyl alcohol, benzyl alcohol, aldehydes and some hydrocarbons contributed more to the NX. In addition, the chemical composition analysis showed that the content of free amino acids was higher in NX green tea samples, while the content of catechins was relatively higher in HX tea samples. A proteomic analysis revealed that most of the enzymes involved in VPBs pathways, such as phenylalanine ammonialyase, peroxidase, and shikimate-O-hydroxycinnamoyl transferase, were more abundant in NX than in HX tea samples. These results laid a foundation for the aroma formation mechanism of different aroma types of baked green tea and provided some theoretical guidance for the breeding of specific aroma varieties.

Elasto-plastic material model of green beech wood

Physically modelling the mechanical response of a tree by numerical simulation depends on having accurate data on the mechanical properties of green hardwood. Lacking such data, we developed and validated an orthotropic elasto-plastic (E–P) material model, based on the results of experiments performed on European beech (Fagus sylvatica L.) green wood, capable of including both the non-linearity and orthotropic properties of the material. We selected 655 clear samples with the special orthotropic structure of annual rings. All samples were prepared immediately after felling; their moisture content (MC) was 80% on average. The mechanical responses in normal directions and shear are represented by bi-linear stress–strain curves. The E–P model was validated by comparing the force–deflection response of three-point bending of green wood samples in a finite-element method (FEM) simulation (the average relative error was 4.6% for point-wise and 1.7% for integral-wise comparison). The output of this work was a consistent set of material constants for the E–P material model that is now available for the structural analysis of beech wood with MC above to fibre saturation point (FSP), especially green wood, subjected to relatively high loads (such that a plastic deformation appears) and that can very well predict a non-linear response above the proportional limits.

Biochemical Characterization of Temi Tea from Sikkim

Tea is the most popular non-alcoholic beverage in the world well known for its refreshing and stimulative properties. Temi tea is a top-notch organic tea brand being grown in the sole tea estate in the mountainous state of Sikkim which has high demand in the international market and has not been studied scientifically so far. Therefore, the present study was conducted to assess and compare the total polyphenol content, total flavonoid content, total tannin content and antioxidant activity in the processed Temi tea samples collected across different season (flush) which is expressed on dry weight basis. Total polyphenols, flavonoid, tannin and antioxidant activity were studied spectrophotometrically. Results of the analysis revealed that the highest total polyphenol content, highest flavonoid content and highest antioxidant activity was found in T1 (Green tea sample of Spring flush) while the highest total tannin content was found in (T2) Black tea (Spring flush).

Weight and structural considerations of potential green roof growth: Media compositions for the Nigerian building industry

Abstract The principal objective of this paper was to assess the physical properties and weight or structural implications of some potential green roof growth media compositions practicable for use in the Nigerian built environment. The study carried out an essential selection of material constituents of growth media blends mixed in a 3:1:1 ratio of natural stone-based gravels, soil and compost respectively. Six substrate blends based on later-ite stones, ory and empirical field evaluation methods. The results revealed that the granite-based blend is the heaviest sample with 1,713.30 kg/m3 in its saturated state, while the lightest in weight is the pumice blend with 869.30 kg/m3 which is 50.7% less than the granite blend. The heaviest and the lightest outlined models were subsequently subjected to a weight analysis on a proposed reinforced concrete flat-roofed structure. The results showed that all the extensive green roof samples fall within the IBC stipulated range. The heaviest granite substrate obtained a design load of 0.951 kN/m2, while the lightest pumice blend recorded a design load of 0.576 kN/m2. Hence, it stands to offer an optimum alternative in green roof retrofitting projects for existing flat-roofed buildings. The study, therefore, submits that all samples evaluated involve readily available materials in the studied area and can be used with respect to their characteristic properties as presented in this study. It also serves as a reference point for all stakeholders in the research and building construction industry in Nigeria and beyond.

Formation of Cysteine Adducts with Chlorogenic Acid in Coffee Beans.

The post-harvest processing of coffee beans leads to a wide range of reactions involving proteins. The formation of crosslinks between proteins and phenolic compounds present in high concentrations of coffee beans represents one of the most challenging and still not fully characterized reactions. The aim of this work was to assess the presence of products from such reactions in coffee samples, focusing on the adducts between cysteine and chlorogenic acids (CQAs). For this purpose, 19 green and 15 roasted coffee samples of the Coffea arabica, Coffea canephora, and Coffea liberica varieties were selected for this study and basically characterized. Then, targeted liquid chromatography mass spectrometry (LC-MS/MS) methods were developed to assess the formation of adducts between CQA and cysteine, glutathione, and N-acetylcysteine as the amino acid and peptide models, and quantified such adducts in coffee samples. The results of the characterization showed a heterogeneous distribution of the protein content (8.7-14.6%), caffeine (0.57-2.62 g/100 g), and antioxidant capacity (2-4.5 g ascorbic acid/100 g) in Arabica, Canephora, and Liberica samples. Glutamic acid, arginine, and proline were found to be the major amino acids, while 5-CQA (38-76%), 3-CQA (4-13%), and 4-CQA (4-13%) were the most abundant CQA derivatives of all coffee varieties. The model experiments for adduct formation demonstrated that cysteine binds to CQA via thiol groups and 5-CQA initially isomerizes to 3- and 4-CQA, depending on the conditions, allowing cysteine to bind to two different sites on 3-, 4- or 5-CQA molecules, thus, forming six different Cys-CQA adducts with m/z 476. The reaction was more favored at pH 9, and the adducts proved to be stable up to 90 °C for 10 min and up to 28 days at room temperature. The relative quantification of adducts showed peak area values ranging from 1100 to 3000 in green coffee bean samples, while no adducts were detected in roasted coffee beans. Overall, this work was the first attempt to demonstrate the presence of Cys-CQA adducts in coffee beans and paves the way for further investigations of such adduct formation at the protein level.

Development of sensory tools for green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) and changes in quality attributes during shelf-life storage.

Green rooibos (Aspalathus linearis (Burm.f.) R.Dahlgren) herbal tea is popular due to its health-promoting properties. Information on its characteristic sensory profile is scarce and sensory tools to define product variation are needed. The storage conditions and time during its shelf-life are hypothesized to affect the product quality. Production batches from two producers spanning 5 years (n = 57) were analyzed using descriptive sensory analysis. Primary attributes (>30 median intensity; 100% occurrence frequency) included 'hay/dried grass', 'cooked oats', 'tobacco', 'honey' and 'caramel' aromas, and astringent mouthfeel. 'Cooked vegetables', 'green grass', 'stewed fruit', 'rooibos-woody', 'marmalade' and 'cardboard' aromas, sweet taste and bitter taste were secondary attributes (10-20 median intensity; 100% occurrence frequency). The same flavor attributes were present, except for sweet-associated and fruity notes. A sensory lexicon and sensory wheels for aroma and palate attributes were constructed from the data. The shelf-life stability of green rooibos was evaluated in moisture-impermeable (pouches) and moisture-permeable (sachets) packaging at 25 and 40 °C at 60% relative humidity over 24 weeks. Green rooibos samples stored in pouches at 4 °C were also evaluated. Storage in sachets led to moisture uptake (~10 g (100 g)-1 dry basis) and an increase in water activity (>0.6), causing degradation of chlorophyll and dihydrochalcones. Changes in color and sensory profile (decreased vegetal, cereal and cardboard aromas and increased sweet-associated and fruity aromas) were evident and more pronounced at the higher storage temperature. Storage at ≤25 °C in moisture-impermeable packaging material is recommended for green rooibos herbal tea. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Green and blue infrastructure as model system for emissions of technology-critical elements

Over the recent decades, technological advancements have led to a rise in the use of so-called technology-critical elements (TCEs). Environmental monitoring of TCEs forms the base to assess whether this leads to increased anthropogenic release and to public health implications. This study employs an exploratory approach to investigate the distribution of the TCEs Li, Be, V, Ga, Ge, Nb, Sb, Te, Ta, Tl, Bi and the REYs (rare-earth elements including yttrium) in urban aerosol in the city of Vienna, Austria.Leaf samples (n = 292) from 8 plant species and two green facades and water samples (n = 18) from the Wienfluss river were examined using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Surface dust contributions were assessed by washing one replicate of each leaf sample and analysing the washing water (n = 146). The impacts of sampling month, plant species and storey level on elemental distribution were assessed by statistical tools and generative deep neural network modelling. Higher TCE levels, including Li, V, Ga, Ge, Tl, Bi, and the REYs, were found in the winter months, likely due to the use of de-icing materials and fossil fuel combustion. A. millefolium and S. heufleriana displayed the highest levels of Li and Ge, respectively. In addition, increased elemental accumulation at lower storeys was observed, including Be, Sb, Bi and the REYs, indicating greater atmospheric dust deposition and recirculation closer to ground level.The results suggest a broad association of TCE levels with urban dust. This study enhances the current understanding of TCE distribution in urban settings and underscores the importance of their inclusion in pollution monitoring. It highlights the complex interplay of human activities, urban infrastructure, and environmental factors, offering valuable insights for managing urban environmental health risks and underlining the need for comprehensive urban ecosystem studies.

Exploring the potentialities of a biodegradable polymeric film in sample preparation: An optimized “white” protocol to extract and quantify emerging contaminants in water

BackgroundThe introduction of white analytical chemistry encourages the development of methods characterized by a balance among greenness, productivity/feasibility and analytical performances. In the environmental analysis of emerging contaminants (ECs), for which high sensitivity and specificity are mandatory, the use of green and sustainable sample preparation needs to be coupled to a reliable analytical determination. Herein, an extraction method based on the use of a biodegradable polymeric film (Mater-Bi) and coupled to LC-MS/MS analysis was developed for the sensitive determination of ECs in wastewater. ResultsThe interaction among a range of ECs and the Mater-Bi film (a commercially available patented blend of polybutylene-terephthalate, starch and fatty acids) was investigated by two sequential experimental designs, to simultaneously study several factors and optimize extraction efficiency. The final method, resembling a fabric phase sorptive extraction, involved pH and ionic strength modification of the sample, 1h extraction and desorption in ethanol. Satisfactory recoveries from real wastewater were obtained for sixteen analytes (56–116 %), as well as excellent precision (inter-day relative standard deviations below 10 % for most compounds). Matrix effect was in the range 88–116 % at the lower pre-concentration factor, but also acceptable in most cases at the higher pre-concentration factor. LODs in matrix, from 0.004 to 0.159 μg L−1, were lower than or comparable to those from recent studies employing green extraction procedures. The method demonstrated its applicability to samples from wastewater treatment plants, allowing quantification of pharmaceuticals and UV filters at the μg L−1 and ng L−1 levels, respectively. SignificanceFor the first time, the synthetic biopolymer Mater-Bi, so far unexplored for the use in analytical chemistry, was exploited for a green, simple and extremely cheap extraction protocol. The optimized method is suitable for several ECs, guaranteeing very good accuracy, precision and specificity, also thanks to the LC-MS/MS analysis. The evaluation by green and white analytical chemistry metrics highlighted its superiority to conventional extraction methods.