Search Results (53)

The reliable quantification of urea in agricultural systems requires methods that combine metrological rigor with low environmental impact. This work develops and validates a micro-Raman method (λ = 532 nm) for the direct determination of urea in aqueous solutions and soils. The method is formally compared with the reference procedure ISO 19746:2017 (HPLC). Calibration, based on the 1000–1200 and 1460–1670 cm⁻¹ windows, showed near-ideal linearity in the 0.25–25% w/w range (r² = 0.9999). LOD and LOQ values were 0.178 and 0.735% w/w, respectively. Intra- and inter-day accuracy proved adequate for routine use (RSD ≤ 5%). A one-way ANOVA (p = 0.983) confirmed no statistically significant differences between concentrations obtained by micro-Raman and ISO 19746:2017. In the soil matrix, recoveries ranged between 94 and 101, and the contained biases demonstrate good tolerance to matrix effects. Application to maize plots allowed for monitoring urea disappearance at three depths (0–2 cm, 5–7 cm and 10–15 cm) over 90 days. These differentiated areas of rapid surface hydrolysis from more persistent fractions at depth. The Eco-Scale (96), GAPI (pictogram dominated by green areas), and AGREE (0.88) metrics confirm a significantly lower environmental footprint than that of the chromatographic method. The proposed micro-Raman methodology is emerging as a green, fast, and traceable alternative for monitoring urea in fertilizers and agricultural soils. Full article

Rapid, sensitive, and environmentally sustainable spectrophotometric methods for the determination of nitrite (${{\mathrm{N}\mathrm{O}}_2}^{-}$) in environmental specimens are proposed. The presented procedures are grounded in the diazotization of sulphathiazole (STZ), followed by coupling with rhodanine (RDN) or 7-hydroxycoumarin (7-HC) in an alkaline medium, and the results were studied. This reaction gave an intense soluble red color at 504 nm and a pale red color at 525 nm for RDN and 7-HC, respectively. The conditions producing the maximum performance and other important analytical criteria in relation to the proposed procedures were investigated to enhance their sensitivity. Beer’s law was abided by for ${{\mathrm{N}\mathrm{O}}_2}^{-}$ over the concentration ranges of 0.08–2.0 µg mL⁻¹ and 0.04–2.4 µg mL⁻¹ using RDN and 7-HC, respectively. The lower limit of detection (LLOD), lower limit of quantification (LLOQ), molar absorptivity (ε), and Sandell’s sensitivity were calculated as follows: 0.0303 µg mL⁻¹, 0.0918 µg mL⁻¹, 4.20 × 10⁴ L mol⁻¹ cm⁻¹, and 1.63 × 10⁻⁶ µg cm⁻² (in the case of RDN); and 0.0387 µg mL⁻¹, 0.1172 µg mL⁻¹, 6.90 × 10⁴ L mol⁻¹ cm⁻¹, and 1.00 × 10⁻⁶ µg cm⁻² (in case of 7-HC). Furthermore, the ecological implications were assessed using three green assessment methodologies: Analytical Eco-Scale (ESA), Analytical GREEnness metric (AGREE), and Green Analytical Procedure Index (GAPI). Thus, our proposed procedures are fully validated and implemented in order to carry out ${{\mathrm{N}\mathrm{O}}_2}^{-}$ quantification in the selected ecological samples (water and soil samples). Full article

Exploring green organic solvents is a global demand. Most of the currently used solvents pose some concerns regarding environmental sustainability and occupational health risks. In this work, propylene glycol was employed for the first time as a green solvent for mobile phase preparation in the reversed phase chromatographic separation of a mixture of two antioxidants, glutathione and ascorbic acid. The slight viscosity of propylene glycol was manipulated by using water as a co-fluidizing agent to facilitate pumping. Method optimization was performed using factorial design experimental Expert 13^® Software (Minneapolis, MN, USA) to achieve the maximum resolution and the minimum run time. The reported method was properly validated according to the International Conference on Harmonization criteria at the linearity range of 1–500 µg/mL, with acceptable accuracy and precision for both drugs. The method was effectively applied for the quantification of both drugs in their commercial pharmaceutical formulation. The proposed method was assessed for environmental and operator safety by means of global tools like AGREE and MoGAPI and has proved high degrees of greenness. Propylene glycol has several benign properties, such as low volatility, less toxicity, compatibility with UV detectors and very low flammability, that will soon assemble it as a promising alternative for the conventionally used solvents. Full article

The application of Green Analytical Chemistry (GAC) principles in method development aims to reduce waste and replace hazardous solvents with environmentally friendly alternatives. Natural Deep Eutectic Solvents (NADESs) have recently emerged as sustainable replacements for traditional organic solvents. In this study, hydrophobic NADESs were used in dispersive liquid–liquid microextraction (DLLME) to extract four synthetic hallucinogenic phenethylamines (2C-B, 25B-NBOMe, 25C-NBOMe, and 25I-NBOMe) in urine samples. Nine NADESs were formed using menthol and different organic acids, with menthol–decanoic acid (1:1 molar ratio) providing the best extraction efficiency. A fractional factorial design identified pH, vortex speed, and vortex time as key factors, which were then optimized using a Box–Behnken design. The statistical model showed strong validity and high predictive power, and the optimal conditions (pH 12, vortex time 20 s, vortex speed 30,000 rpm, centrifugation at 14,000 rpm for 3 min) resulted in the highest recoveries. Greenness and operational sustainability, evaluated using ComplexGAPI, AGREEprep, BAGI, and SPRS tools, revealed clear advantages over existing extraction approaches. Overall, the proposed method represents a sustainable, white-chemistry–driven microextraction strategy suitable for clinical and forensic toxicological applications. Full article

A novel, green, stability-illustrating HPLC-DAD method was validated for the simultaneous analysis of menadione (MND), dimetridazole (DMT), and sulfadimethoxine sodium (SLF) in a veterinary powder for the first time. These compounds are commonly combined in veterinary premixes and powders to enhance animal growth, prevent bacterial infections, and improve feed efficiency. Separation was achieved isocratically on a C18 column using a mobile phase of 0.05M KH₂PO₄: acetonitrile (80:20, v/v) at a flow rate of 2.0 mL/min, with detection at 260 nm. The represented HPLC-DAD method was rapid, yielding retention times under 5.2 min, and exhibited excellent linearity over the tested ranges (10.0–30.0, 20.0–60.0, and 20.0–60.0 µg/mL for MND, DMT, and SLF, respectively). Forced degradation studies, conducted according to the International Council for Harmonisation (ICH) guidelines, confirmed the method’s specificity in distinguishing the active pharmaceutical ingredients from their degradation products. The highest degradation was observed for MND (photolytic, 26.52%), DMT (alkaline, 21.12%), and SLF (oxidative, 27.16%). The method’s environmental sustainability was evaluated using the Analytical GREEnness (AGREE) metric (score: 0.75) and the Green Analytical Procedure Index (GAPI), while its practicality was supported by a high Blue Applicability Grade Index (BAGI) score of 80.0. This stability-indicating method represents the first robust, green, and reliable analytical approach for this triple veterinary formulation. Full article

Wild Physalis angulata L. has promising medicinal potential due to its rich flavonoids. However, a green analytical approach for these compounds from this plant has not yet been thoroughly optimized. Therefore, this study optimized ultrasound-assisted extraction using the response surface method for the UV-VIS spectroscopic determination of the total flavonoid content in P. angulata in Vietnam. Notably, the greenness of the whole procedure was evaluated by AGREE, Eco-Scale, GAPI, BAGI methodologies. The Box–Behnken model was applied to design the experiments with four variables: ethanol concentration, solid-to-liquid ratio, extraction temperature, and time. The UV-Vis spectrophotometric method was validated at 510 nm according to AOAC guidelines and met all the requirements, including specificity, linearity (R² = 0.9996) in the working range of 15–120 µg/mL, repeatability (RSD = 1.89%), intermediate precision (RSD = 2.21%), and accuracy (recoveries from 99.52 to 104.06%). The limits of detection (LOD) and quantification (LOQ) were 2.48 µg/mL and 7.52 µg/mL, respectively; however, to avoid noise signal at lower concentrations, the validated lower limit of quantification (LLOQ) was set at 15 µg/mL. Data were analyzed using second-order regression. The R² = 0.9726 shows a close correlation between variables and the experimental data. The optimal extraction conditions were 31.66% ethanol, 30:1 mL/g ratio, 80 °C and 48.73 min. The predicted values (38.09 ± 1.70 mg RU/g) were not statistically different from the experimental values (34.58 ± 0.87 mg RU/g), confirming the model’s accuracy and applicability in optimizing the extraction process. The ultrasound-assisted extraction was optimized to enhance the flavonoid extraction yield from P. angulata, providing a solid scientific foundation for further pharmacological research. Full article

In this study, a magnet-integrated fabric phase sorptive extraction (MI-FPSE) protocol was developed in combination with high pressure liquid chromatography—diode array detection (HPLC-DAD) for the simultaneous determination of five phenylurea pesticides (i.e., chlorbromuron, diuron, linuron, metoxuron, monuron) in environmental water samples. To produce the MI-FPSE device, two individual sol-gel coated carbowax 20 M (CW 20 M) cellulose membranes were fabricated and stitched to each other, while a magnetic rod was inserted between them to give the resulting device the ability to spin and serve as a stand-alone microextraction platform. The adsorption and desorption step of the MI-FPSE protocol was optimized to achieve high extraction efficiency and the MI-FPSE-HPLC-DAD method was validated in terms of linearity, sensitivity, selectivity, accuracy, and precision. The limits of detection (LODs) were found to be 0.3 μg L⁻¹. The relative recoveries were 85.2–110.0% for the intra-day and 87.7–103.2% for the inter-day study. The relative standard deviations were better than 13% in all cases. The green character and the practicality of the developed procedure were assessed using ComplexGAPI and Blue Analytical Grade Index metric tools, showing good method performance. Finally, the developed method was successfully used for the analysis of tap, river, and lake water samples. Full article

Precise and convenient analytical methods are needed for the quantitative determination of calcium in water and food. Complexometric titration remains a reliable technique to determine calcium in milligram amounts. The titrations have been performed automatically by detecting color transitions with a webcam. Classical complexometric indicator calcein provided a sharp color transition. In diffuse reflection mode, the color appearance parameter (Hue) provides better precision and is more resistant to ambient light fluctuations compared to RGB primaries. In fluorescence mode with LED illumination, the fluorescence brightness of calcein is independent of ambient light, and the primary green color provides the sharpest endpoints. The color change during titration is better in the upper part of the acquired images due to the internal filter effect in calcein solutions. The automatic titration with a digital burette provides a standard deviation as low as 0.1 μmol. An example of its application is in the determination of calcium in commercial mineral waters. Based on the AGREE and ComplexMoGAPI rating scales, the semi-automatic titration showed better environmental assessment compared to the standard ASA method. Full article

Background: In response to the growing demand for the real-time, in-field characterization of odorous anthropogenic emissions, this study develops and uses a MEMS-based micropacked thermal desorption Gas Chromatography system coupled with a PhotoIonization Detector (GC/PID) for Hot Mix Asphalt (HMA) plant emissions. Methods: The innovative portable device, Pyxis GC, enables the high-sensitivity profiling of Volatile Organic Compounds (VOCs), particularly aldehydes and ketones, with sub-ppb detection limits using ambient air as the carrier gas. A comprehensive experimental design optimized the preconcentration parameters, resulting in an efficient, green analytical method evaluated via the Green Analytical Procedure Index (GAPI). Sorbent comparison showed quinoxaline-bridged cavitands outperform the conventional materials. Results and conclusions: The method was successfully deployed on site for source-specific sampling at an HMA plant, generating robust emission fingerprints. To assess environmental impact, a Generalized Additive Model (GAM) was developed, incorporating the process temperature and Sum of Odour Activity Values (SOAV) to predict odour concentrations. The model revealed a significant non-linear influence of temperature on emissions and validated its predictive capability despite the limited sample size. This integrated analytical–statistical approach demonstrates the utility of MEMS technology for real-time air quality assessment and odour dispersion modelling, offering a powerful tool for environmental monitoring and regulatory compliance. Full article

In the current study, the Prussian blue analog decorated with zinc oxide (PBA@ZnO) was produced using a simple chemical co-precipitation method. The nanohybrid was examined using XRD, EDX, SEM, and TEM techniques, where it exhibited a polycrystalline structure with highly intense broadening peaks. The surface morphology was observed as thin nanosheets decorated with tiny spheres. Following excitation at 360 nm, the fluorescence spectra of PBA@ZnO showed fluorescence emission at 455 nm. The developed PBA@ZnO was used to qualitatively and quantitatively assess sunset yellow (SY), where its native fluorescence was selectively quenched as SY concentrations increased. For the first time, PBA@ZnO was used as a turn-off nano-sensor for the spectrofluorimetric measurement of SY. The method’s markable sensitivity was demonstrated within an SY linearity range of 50–500 ng/mL, where the limit of detection was calculated as 9.77 ng/mL. Real sample analysis in the food industry, including samples from real food, soft drinks, and sun cream, was made possible by the detection of tiny amounts of SY. Analytical Greenness (AGREE), AGREEprep, and the complementing Green Analytical Procedure Index (Complex MoGAPI) were used to illustrate the new approach’s exceptional eco-friendliness and greenness. The RGB 12 algorithm worked to demonstrate that the suggested approach is less costly, more environmentally friendly, more sustainable, analytically sound, and whiter than the ones that were previously published. In accordance with ICH principles, the suggested method was validated. This approach offers a promising way to rapidly and accurately identify and measure SY in the food industry, helping to guarantee food safety and maintain the health of customers. Full article

A miniaturised, eco-friendly and efficient multiclass method for the simultaneous determination of 87 veterinary drugs, pesticides and mycotoxin residues in beef muscle samples by ionic liquid-based dispersive liquid–liquid microextraction (IL–DLLME) and liquid chromatography tandem mass spectrometry (LC–MS/MS) was developed and validated according to Commission Implementing Regulation (EU) 2021/808 and ISO/IEC 17025: 2017. Under IL–DLLME optimum conditions, matrix calibration yielded a coefficient of determination (R²) ranging from 0.99942 to 0.99997. The limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.93 to 23.78 µg kg⁻¹ and from 1.98 to 38.27 µg kg⁻¹, respectively. Recoveries ranged from 80.0 to 109.8% and the decision limit (CCα) values ranged from 13.0 to 523.0 µg kg⁻¹. Repeatability and reproducibility values were achieved in the ranges of 1.55–12.91% and 1.44–13.35%, respectively. The validated method was applied to 50 real beef samples and 12% of the tested samples contained traces of some residues, but they were all below their respective LOQs and CCα; hence, the beef was fit for human consumption. The greenness of the method was assessed using five green analytical chemistry (GAC) metrics, namely, the Analytical Eco-Scale (AES), NEMI, GAPI, AGREE and ComplexGAPI, and found to be green according to the AES metric and Analytical GREEnness Metric Approach and Software (AGREE). The method provided better results at a greatly reduced cost and analysis time in comparison with standard method. Full article

As a kind of bioactive component in the rhizome of natural plant Curcuma longa L. (turmeric), curcumin is almost insoluble in water at neutral and acidic pH, which limits its further utilization and development. At the same time, traditional extraction and separation processes typically require the use of a large number of organic solvents. Ionic liquids (ILs) are organic molten salts with melting points below 100 °C. When an ionic liquid exists in a liquid state at or near room temperature, it is referred to as a room-temperature ionic liquid (RTIL). They have a temperature range, good physical and chemical stability, and good structural designability. They have a strong solubilization enhancement effect for many organic compounds. This study first explored the molecular forms of curcumin in ionic liquid aqueous solutions and the intermolecular interactions between curcumin and ionic liquids using spectral analysis and computational chemistry methods; furthermore, using an ionic liquid aqueous solution as an extraction agent, curcumin-like substances (curcuminoids) were extracted from turmeric powders under ultrasound assisted conditions, revealing the relationship between the structure of the ionic liquid and the extraction efficiency. After that, a kinetic study was conducted for the extraction of curcuminoids from turmeric powders, using second-order kinetics fitting to obtain the rate constant and initial extraction rate during the extraction process. Finally, the comparison with a ComplexGAPI tool and antioxidant experiment was performed on the extraction by using ionic liquids and traditional solvent. The full results can provide reference for the design of IL extractants and their application for natural products. Full article

This study investigated the lung-protective effects of Atractylodis Rhizoma extracts (the root of Atractylodes japonica Koidz. ex Kitam), known as AJ extracts, in mitigating subacute pulmonary injuries caused by particulate matter 2.5 (PM_2.5) exposure in Balb/c mice. AJ was given orally at concentrations of 400, 200, and 100 mg/kg, demonstrating a promising impact by mitigating oxidative stress and inflammation associated with phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) and p38 mitogen-activated protein kinase α (p38 MAPKα) pathways and reducing mucus overproduction. These protective effects were achieved through the downregulation of p38 MAPKα and PI3K/Akt mRNA expressions, enhanced anti-inflammatory and antioxidant activities, and increased mucolytic expectorant effects arbitrated by elevated lung acetylcholine (ACh) and substance P levels, along with decreased mRNA expressions of MUC5AC and MUC5B. Importantly, these outcomes occurred without significant hepatotoxicity. While all AJ dosages provided dose-dependent pulmonary protection, their effects were less pronounced than those of dexamethasone (DEXA) at 0.75 mg/kg. However, AJ uniquely exhibited mucolytic expectorant activities absent in DEXA-treated mice. The results indicate that A. japonica may serve as a potential candidate for creating alternative treatments for respiratory conditions or as an ingredient in functional foods. Full article

An ultrasound-assisted dispersive liquid–liquid microextraction (DLLME) method was developed to concentrate and quantify rare earth elements (REEs) (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) in acidic aqueous solutions. Tetrachloroethylene (PCE) was used as the diluent, di-(2-ethyl hexyl) phosphoric acid (D2EHPA) as the extracting agent, and acetone as the dispersant solvent. The method was optimized at pH = 2.3, T = 25 °C, and V_S = 400 µL of a PCE ÷ D2EHPA mixture (10 ÷ 1) using the response surface methodology (RSM) with a Box–Behnken design. Under optimal conditions, the method proved efficient for the DLLME of most REEs (Y, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), where the achieved recoveries were in the range of 61–109%, while relative standard deviations were in the range 11–28%. The proposed method was applied to recover REEs from real coal ash leachate samples. A greenness evaluation using the Green Analytical Procedure Index (GAPI), Analytical GREEnness (AGREE), and Analytical Eco-Scale (AES) methodologies revealed acceptable metric scores of 74, 0.61, and 26.6–79.8, respectively. Full article

This study investigated the growing environmental concern of particulate matter (PM)-induced pulmonary injury and explored novel preventive strategies. In particular, it evaluated the protective effects of Atractylodes japonica Koidz. ex. Kitam root extract (AJ), which is known for its anti-inflammatory and antioxidant properties, against PM_2.5-induced subacute pulmonary injuries in Balb/c mice. The experimental design involved administering AJ at a concentration from 400 to 100 mg/kg over a ten-day period, with comparisons made to the mucolytic agent ambroxol hydrochloride (AX). The results revealed that AJ significantly alleviated PM_2.5-induced pulmonary injuries, mucus overproduction, and respiratory acidosis in a dose-dependent manner. Notably, body surface redness was reduced by up to 55% at a concentration of 100 mg/kg compared to the control. These effects were evidenced by reduced mRNA expression of the mucus-associated genes MUC5B and MUC5AC and increased concentrations of substance P (up to 475%) and acetylcholine (up to 355%) in the lungs at 400 mg/kg, compared to the intact vehicle control. Particularly, the 400 mg/kg dose of AJ demonstrated comparable effectiveness to AX, highlighting its potent mucolytic and expectorant activities. The results of this study highlight the fact that AJ could act as a promising alternative for respiratory protection, with potential applications as a functional food ingredient. This study substantiates AJ’s role in enhancing respiratory health, emphasizing its capacity as a candidate for further development into therapeutic agents against toxic environmental exposure. Full article