This study employed flame atomic absorption spectrophotometry to determine the levels of selected heavy metals in Swiss chard. Samples were collected from three vicinities of Addis Ababa: Akaki, Sebeta, and Kotebe. A 0.5-g dried and powdered sample was analyzed using the wet digestion method with 69%-72% HNO3 and 70% HClO4, with optimized digestion. The calibration curves and coefficient (r) value were between 0.996 and 0.999, showing very good linearity. The accuracy of the optimized procedure was tested using samples that had a known amount of the substance added. The recovery percentages ranged from 95.89% to 100%, which is a good range. The mean concentrations (mg/kg) of nickel (0.017) and zinc (0.088) in the Swiss chard were determined . The mean concentrations of metals in Swiss chard from the three areas indicated a higher concentration of zinc in Kotebe compared to Akaki and Sebeta. A higher concentration of nickel (Ni) was found in Akaki's Swiss chard compared to Sebeta and Kotebe. The Pearson correlation coefficients of metals from the Swiss chard between nickel and zinc showed a very strong correlation. The best approach combines immediate risk reduction such as cleaner irrigation and consumer warnings, with long-term remediation such as soil treatment, pollution control, and policy enforcement to protect both farmers and consumers.
This paper presents a method combining a thermal desorption (TD) unit with gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to determine compound specific δ13C values of seven VOCs (benzene, toluene, ethylbenzene, m/p-xylene, o-Xylene, styrene, and cumene). The main innovation lies in the systematic validation of TD-GC-C-IRMS for atmospheric VOC analysis, which enables reliable δ13C determination with minimal isotopic bias. The optimal TD conditions were 300°C and 5 min. Advantages include high precision (SD ≤ 0.4‰), good reproducibility, long-term sample stability (up to 50 days), and suitability for on-site air sampling. Limitations are the coverage of only seven compounds and a wider range of VOC species and more complex matrices should be addressed in future work. The method was successfully applied to ambient air samples, and isotopic signatures indicated that VOCs were mainly derived from traffic-related emissions. This approach provides a robust and practical tool for source identification of atmospheric VOCs and supports source apportionment studies in environmental research.
The integration of artificial intelligence (AI) plays a crucial role in modern analytical chemistry, offering solutions to long-standing challenges. Conventional techniques, such as spectrophotometric analysis and chromatography, often face issues like spectral overlap, matrix interference, and extensive experimental optimization. AI and machine learning (ML) approaches address these limitations by enabling spectral deconvolution, pattern recognition, prediction of retention factors, and automated optimization of separation conditions. Beyond enhancing traditional methods, AI supports the development of innovative analytical platforms. Modern analytical chemistry increasingly relies on smartphone- and paper-based sensors for on-site detection of biomarkers and pollutants. These portable, low-cost systems generate complex datasets requiring advanced computational tools, where AI can improve reliability and sensitivity when validated. AI also plays a vital role in synthesizing and optimizing nanomaterials such as carbon quantum dots (CQDs), accelerating experimental fine-tuning through predictive modeling and optimization algorithms. Moreover, AI facilitates the interpretation of large-scale data, providing deeper insights while reducing human error and analysis time. Despite these advancements, challenges remain regarding model interpretability and the integration of heterogeneous datasets. Addressing these requires explainable ML methods that bridge computational predictions with chemical reasoning. This review highlights current AI applications in chromatographic analysis, drug stability studies, and modern analytical chemistry, discusses implementation challenges, and explores future trends shaping the next generation of intelligent analytical systems.
Metformin, a widely prescribed antihyperglycemic agent, plays a crucial role in the management of Type 2 diabetes by reducing hepatic glucose production and increasing insulin sensitivity. Its effectiveness in glucose regulation has made it a cornerstone in diabetes care, necessitating precise monitoring of drug levels to optimize therapeutic outcomes and minimize potential adverse effects. This review explores contemporary biosensor technologies designed for the sensitive detection of metformin, emphasizing their significance in clinical and pharmaceutical settings. We analyze various biosensor platforms, including electrochemical, optical, and piezoelectric systems, highlighting their principles, advantages, and challenges. Additionally, we discuss the integration of nanomaterials to enhance detection sensitivity and specificity. Given the rising prevalence of diabetes globally, the development of innovative biosensing strategies for metformin detection is paramount in ensuring effective patient management and improving treatment adherence. The insights gained from this review aim to propel further research and development in this vital area of biomedical engineering.
Volatile organic compounds (VOCs) emitted in human matrices have gained attention for their potential in noninvasive disease detection, utilizing canine olfaction and chemical analysis. However, the stability of these VOCs under various storage conditions remains poorly understood, presenting a challenge to accurate diagnostics. This study investigates the effects of storage temperature and time on VOC conservation using three types of sorbents, Sorbstars, Twisters and Getxent, without the aim of directly comparing sorbent performance. Initially, synthetic sweat-like mixtures were analyzed on Sorbstars and Getxent, revealing unexpected increases in signal intensity after 1 month and 2 months, which led to a shift toward human sweat samples for a more realistic assessment. Long-term storage of human sweat samples collected on Sorbstars resulted in a marked decrease in total VOC signal intensity, with losses exceeding 80% after 18 months. Short-term studies (2-3 months, Sorbstar and Twisters) revealed temperature-dependent changes in VOC signal intensity that varied by VOC and sorbent. Overall, these results highlight the importance of storage temperature and duration in VOC conservation. As a preliminary study, these findings emphasize that VOC stability should be characterized for the specific VOCs of interest and that further investigations are required to establish robust and compound-specific conservation protocols across different storage conditions.
A fast, simple, and precise stability-indicating high-performance liquid chromatographic (HPLC) method was developed for analysis of triclabendazole (TBZ) and levamisole (LEV) in oral suspension. Using a mobile phase composed of acetonitrile, methanol, and water (50:40:10, v/v/v), with the pH adjusted to 4.6 with 0.1 M phosphoric acid. The mobile phase was filtered, degassed, and pumped at a flow rate of 1.0 mL/min. Detection was performed at 245 nm. The proposed method was validated with respect to specificity, linearity, limit of detection (LOD) and limit of quantification (LOQ), interday and intraday precision, robustness, and accuracy. The retention times for TBZ and LEV were found to be about 3.116 and 1.385 min, respectively. Calibration plots were linear with correlation coefficient of 0.9999 in the concentration range of 200-800 and 150-600 μg/mL for TBZ and LEV, respectively. The method was verified to be stability indicating by separating the active ingredients from their stressed testing degradation products. The procedure proved acceptable robustness to variations in flow rate, wavelength, and column temperature. The method was conveniently used for the analysis of TBZ and LEV in oral suspension.
This study aimed to measure the concentrations of essential and nonessential metals in raw and cooked rice samples from Ethiopia. Researchers collected rice samples, both local and imported, from the Jimma town market. The samples were stored in prerinsed plastic bags and rinsed with 2 mol/L HNO3 and deionized water to prevent contamination. Preparation involved wet digestion methods, and the samples were stored at 4°C until analysis. Flame atomic absorption spectrometry (FAAS) was used to analyze the samples in triplicate, and the results were validated for accuracy, precision, instrument detection limit (IDL), limit of detection (LOD), and limit of quantification (LOQ). The findings revealed significant differences (p<0.05) in the mean concentrations of metals across all rice samples. The metals detected included both essential and nonessential types: chromium (Cr) ranged from nondetectable (ND) to 15.36 mg/kg; nickel (Ni) from ND to 17.76 mg/kg; cadmium (Cd) from 1.22 to 5.58 mg/kg; lead (Pb) from 0.17 to 0.98 mg/kg; iron (Fe) from 19.99 to 84.71 mg/kg; calcium (Ca) from 35.15 to 198.53 mg/kg; potassium (K) from 35.31 to 105.19 mg/kg; and magnesium (Mg) from 18.66 to 46.07 mg/kg. The percentage recoveries ranged from 80.5% to 120%, indicating good accuracy and repeatability of the analytical procedure. The study also found significant variations among the six metals, suggesting that geographic origin influences metal levels in rice. Notably, while there was no significant difference between cadmium and calcium concentrations, the levels of nonessential metals, cadmium, lead, and nickel, exceeded the recommended limits set by WHO/FAO. Based on these findings, the study recommends careful handling of rice during transportation, marketing, storage, and cultivation to minimize exposure to toxic metals.
Understanding the chemical composition of plants is essential for elucidating their evolutionary adaptations and evaluating the pharmaceutical potential of their primary and secondary metabolites. In this study, we compared the primary and secondary metabolites of three closely related Fritillaria species from the Qinghai-Tibetan Plateau using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). Chemical constituents were qualitatively identified based on accurate mass measurements combined with MS1 and MS2 fragmentation information. A total of 72 compounds were identified across the three Fritillaria species. All species exhibited rich chemical diversity and demonstrated considerable medicinal potential. The differential metabolites included several bioactive compounds, such as peimine and verticine 3-glucoside, among others. In addition, F. thunbergii showed unique alkaloids, including zhebeinine, distinguishing it from the other two species. These findings provide a valuable basis for understanding differences in pharmacological metabolism among the three Fritillaria species and highlight newly reported constituents that expand the known chemical diversity of the genus, offering potential implications for species discrimination, quality evaluation, and rational resource utilization.
Fig (Ficus carica) is a fruit rich in bioactive compounds with potential health benefits, including the ability to modulate blood glucose levels and reduce oxidative stress. Efficient extraction of these bioactive molecules is essential to enhance their applications in functional and nutraceutical formulations. The efficiency of recovery, however, depends strongly on solvent polarity and extraction parameters. This study evaluated the effect of solvent polarity and extraction time on phytochemical recovery and antioxidant activity of fig powder. The phytochemical evaluation revealed significant variation among solvents. Methanolic extracts showed the highest total polyphenol content (3.15 ± 0.1 mg GAE/g) and exhibited superior antioxidant activities compared to aqueous and ethanolic extracts, particularly at 45 min of extraction. Antioxidant potential was confirmed by DPPH radical scavenging activity (70.2 ± 2.3%), ferric reducing antioxidant power (FRAP) (16.6 ± 0.8 μM·TE/g), ABTS radical cation inhibition (9.5 ± 0.4 μM·TE/g), metal chelating activity (67 ± 3.8%), and β-carotene and linoleic acid assay (66.53 ± 3.68%). Proximate analysis confirmed fig powder as a fiber-rich, low-fat matrix suitable for functional food applications. These findings indicate that solvent type and extraction time directly influence bioactive yield and antioxidant performance. Methanolic extraction at 45 min was determined to be the optimal condition for maximizing phenolic recovery and antioxidant activity. The results reinforce Ficus carica as a valuable natural source of phenolics and antioxidants with promising applications in the formulation of functional foods and nutraceuticals.
A common combination of methocarbamol (MTH) and diclofenac potassium (DCL K) relieves musculoskeletal pain and inflammation through centrally acting muscle relaxants. A dual-function RP-HPLC method was used to analyze the assay and dissolution testing of MTH and DCL K simultaneously. As part of the suggested method, green and white analytical chemistry standards were incorporated to ensure sustainability and compatibility. We performed a chromatographic separation on a C8 column (15 cm × 4.6 mm, 5 μm) with a mobile phase of phosphate buffer and ethanol (30:70 v/v), adjusted to pH 2.5 ± 0.1, yielding sharp and well-resolved peaks with retention times of 2.183 min for MTH and 6.652 min for DCL. A 275-nm dual UV detector was used to detect the separation at a flow rate of 1.0 mL/min. Sensitivity parameters demonstrated low detection capabilities, with limits of detection (LOD) of 0.069 μg/mL for MTH and 0.012 μg/mL for DCL, and limits of quantification (LOQ) of 0.210 μg/mL and 0.035 μg/mL. Over an extended sample period of 30 min with 100 revolutions per minute (rpm), USP Apparatus II (Paddle) was used to measure dissolution at a temperature of 37.0 ± 0.5°C in phosphate buffer (pH 6.8). With both active pharmaceutical ingredients, 75% of the drug was released within 30 min. A combination of suitability (RSD 2%) and precision (raw data 2%) makes the method an excellent choice for routine quality control. In keeping with the changing environment and regulatory requirements, pharmaceutical analysis can become more efficient and sustainable. Accelerated stability studies were conducted on the finished dosage form under ICH-recommended conditions for 6 months. Sustainability was assessed using the Analytical Eco-Scale, Environmental and Practical Performance Index (EPPI), and Click Analytical Chemistry Index (CACI). The method achieved an Eco-Scale score of 91, classifying it as an excellent green method, an EPPI score of 97.9, and a CACI score of 80, confirming its efficiency and practicality for routine quality control.
Honey is a nutritive sugar alternative, well-accepted over decades due to its natural source, and a global populace drive toward natural and healthier lifestyle options. Its quality assessment includes 5-hydroxymethylfurfural (5-HMF) content, which measures freshness, but has been linked to cancer. The ability to test for this neo-formed contaminant, 5-HMF, should therefore not be compromised, even in a resource-constrained setting. In this study, a modified reversed-phase HPLC method for the assay of 5-HMF levels in honey has been developed. A nonpolar C-18 column of dimension 3.0 × 150 mm; 2.7 μm was the stationary phase of choice, while a combination of 10:90% v/v of methanol and distilled water, with 1% formic acid, was employed as the mobile phase. Detection was by diode array at a wavelength of 295 nm, using an injection volume of 1 μL. At a flow rate of 0.5 mL/min, the total runtime of the method was 8 min, with the average retention time for 5-HMF recorded at 3.87 ± 0.05 min. Validation of the method was conducted using International Council for Harmonisation guidelines, over the range of 1.25-30.0 μg/mL. It was further employed to quantify 5-HMF in 20 honey samples on the Ghanaian market with varying origin, extraction source and production state, using methanol as the dissolution solvent to ensure stability of the target compound throughout the analysis. 5-HMF levels assayed in the honey samples ranged from 0.8176 ± 0.182 to 81.1619 ± 2.1169 mg/kg of honey. At the time of analysis, 5-HMF contents of all samples except one were within the acceptable limit of ≤ 80 mg/kg of honey, set by the International Honey Commission. The 5-HMF levels quantified in market samples approved by Ghana's Food and Drugs Authority were within the acceptable limit. The developed method is comparatively cheaper and can be successfully used to analyse 5-HMF in honey samples.
Dipyrone (metamizole) is widely used as a nonopioid analgesic in perioperative and intensive care settings; however, its administration may be associated with severe adverse effects. In this study, we describe an analytical assay for the quantification of the active metabolites 4-methylaminoantipyrine (4-MAA) and 4-aminoantipyrine (4-AA) in human plasma using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). In addition, the protein-unbound fractions of both metabolites were determined by ultrafiltration. Chromatographic separation was performed on a UPLC system using gradient elution, followed by MS/MS detection with an electrospray ionization source. The limits of detection for both metabolites were 100 ng/mL. Across the investigated concentration range (100-10,000 ng/mL), the relative error (%RE) ranged from -6.3% to +3.5%. Intra-day and inter-assay variability were below 10%. Method validation was conducted in accordance with the 2018 FDA Bioanalytical Method Validation Guidance, and all evaluated parameters met the required criteria for analytical accuracy and precision. The developed assay is suitable for monitoring dipyrone metabolites and may support the prevention of potential overdosing during prolonged analgesic therapy or in intensive care settings.
Over the last few years, N-nitrosodimethylamine (NDMA) has become a significant environmental contaminant with both anthropogenic and natural sources. The alarming profile of it can be explained by the fact that it is a genotoxic substance and easily spreads through the atmospheric and water systems. The production of NDMA takes place through a variety of pathways, such as industrial, agricultural, municipal, and atmospheric production, and its great aqueous solubility and low soil adsorption capacity enable it to pass through different environmental media easily. The review brings together modern knowledge on the origins of NDMA, its transportation in the environment via air, water, and soil, and its subsequent transformation. The analysis also compares detection methodology with some highly advanced methods of mass spectrometry that can detect trace quantities in complex environmental and pharmaceutical matrices. Ecotoxicological data point to the fact that NDMA is capable of compromising genetic integrity and reproductive fitness as well as causing systemic disruptions in aquatic and terrestrial life and has a long-term effect on the stability of ecosystems. In humans, sustained consumption, through drinking water or ingesting contaminated food, is linked to increased cancer risk and possible negative effects on reproduction and immune health. Although progress has been achieved in treatment and control, a major unresolved challenge remains the lack of harmonized global regulatory thresholds and standardized long-term monitoring data, which limits accurate assessment of chronic low-dose exposure and cumulative ecological and human health risks associated with NDMA. The next steps must aim at the development of predictive molecular models, the extension of the toxicological research to neglected ecosystems, and the promotion of the international partnership in the surveillance to support the establishment of more robust regulations and protection.
Boerhavia elegans has long-held medicinal importance, yet its comprehensive phytochemical and biological characterization remains limited. This study provides the first integrated analysis combining HPLC, GC-MS, and molecular docking to correlate the chemical composition of B. elegans with its antioxidant and cytotoxic activities across different plant parts and solvent systems. Antioxidant assays revealed that polar leaf extracts exhibited the highest activity, with a DPPH IC50 value of 16.73 μg/mL. The methanolic stem extract showed the greatest phenolic content (25.89 mg GAE/100 mg), and the methanolic seed extract had the highest flavonoid yield (6.717 mg QE/100 mg). Ethyl acetate favored flavonoid extraction from the stem (18.29 mg QE/100 mg), while diethyl ether was most effective for the roots (10.21 mg QE/100 mg). UHPLC-DAD identified 15 phenolic compounds with detection limits ranging from 0.47 to 2.20 μg/mL. Cytotoxicity assays demonstrated strong inhibitory effects, with the methanol leaf extract showing 82.5% inhibition of HepG2 cells and the ethyl acetate root extract inhibiting 83.55% of MCF-7 cells. The hexane leaf extract produced the highest inhibition (88.8%) of MDA-MB-231 cells. GC-MS analysis revealed bioactive molecules such as phytol, stigmasterol, and hexadecanoic acid, which were further validated by molecular docking interactions with vimentin and BCL-2 proteins, suggesting potential anticancer mechanisms.
Soil heavy metal contamination has become a global environmental issue, posing long-term risks to ecosystems, human health, and agricultural sustainability. In regions like Fujian Province, China, soil pollution is exacerbated by both agricultural and industrial activities, with tobacco-growing areas facing heightened risks due to heavy metal accumulation. This study aimed to assess the contamination levels, ecological risks, and sources of seven key heavy metals (Pb, Cd, Hg, Cr, As, Cu, and Zn) in the tobacco-growing soils of Liancheng County, Fujian Province. We employed a combination of pollution indices (Pi and Pn), ecological risk indices (RI and Igeo), and multivariate statistical methods (principal component analysis [PCA]/positive matrix factorization [PMF]) to evaluate the pollution levels, ecological risks, and trace pollution sources. The findings indicate that while the overall pollution level is relatively low, localized ecological risks, particularly from Cd and Hg, pose significant concerns. This study demonstrates that while the overall pollution level in the tobacco-growing soils of Liancheng County remains relatively low, localized ecological risks—particularly from cadmium (Cd) and mercury (Hg)—are significant. By integrating pollution indices and multivariate models (PCA/PMF), we quantitatively apportioned the heavy metal sources into four categories: emissions from nonferrous metal smelting and chemical industries (32%), agricultural inputs (30%), natural sources (23%), and traffic emissions (15%). Our findings underscore that anthropogenic activities, especially industrial processes and agricultural practices, are the dominant drivers of soil contamination in this region, providing a critical scientific basis for targeted pollution control and environmental management in similar agroecosystems. The results provide a valuable framework for future pollution control strategies and offer critical insights for environmental management in similar regions worldwide.
Oleanolic acid (OL) and genistein (GN) are bioactive compounds known for their anti-inflammatory, antioxidant, antiviral, cardioprotective, and anticancer properties. Their synergistic therapeutic potential motivated the development of a hybrid nanoformulation, comprising GN nanoparticles incorporated into an OL-loaded liposomal system named GOL. The formulation was extensively characterized for particle size, polydispersity index, zeta potential, entrapment efficiency, and pharmacokinetic behavior, demonstrating its suitability for co-delivery of both drugs. To accurately quantify OL and GN in the GOL system, a robust HPLC-UV method was developed and validated. Simultaneous determination was challenging due to distinct chemical and spectral properties; OL showed lambda max at 210-215 nm, while GN had lambda max at 215, 270, and 336 nm. Optimization using a Box-Behnken design yielded a method using a C18 column with a methanol-acetonitrile-water-tetrahydrofuran (60:20:8:12, v/v) mobile phase and detection at 230 nm. Retention times were 4.8 and 9.9 min for OL and GN. Plasma samples were processed via simple protein precipitation. The method met ICH validation criteria for sensitivity, selectivity, accuracy, precision, robustness, and stability. Finally, the developed method was successfully applied to analyze both drugs from the GOL nanoformulation in both biological fluids and polymeric matrices, enabling a reliable assessment of drug content and stability.
Innovative adsorbent materials have been developed to meet the increasing demand for effective, environmentally friendly methods to remove oil from water sources. The main objectives of this study were to synthesize and characterize a nanocomposite containing Fe3O4 nanoparticle-impregnated biomass and alfalfa waste (Fe3O4@BioAW). Coprecipitation and impregnation methods were combined to produce the nanocomposite, thereby enhancing the capacity of the biomass/alfalfa adsorbent for oil adsorption. Comprehensive characterization, including FTIR, XRD, and SEM, enabled the examination of the adsorbent's morphological and structural properties. The material exhibited a high oil adsorption capacity of 6.671 g/g (removal efficiency of 87.03%) at pH = 5.0 in adsorption studies using a simulated oil-water system with the Fe3O4@BioAW adsorbent. The adsorption equilibrium data were well described by the Langmuir isotherm model (R-2 = 0.9394; R-L = 0.07). The pseudo-second-order kinetic model fit the data reasonably well (R-2 = 0.9953). This study demonstrates the effective use of alfalfa-based biomass combined with magnetic Fe3O4 nanoparticles for efficient oil removal and facile recovery and reuse, highlighting its potential for environmental remediation and wastewater treatment.
A rapid and environmentally friendly analytical method was developed and validated for the simultaneous quantification of four antibiotic residues (enrofloxacin, ofloxacin, sulfamethizole, and trimethoprim) in bear bile powder. The optimized procedure features a simplified sample preparation with minimal solvent consumption and a fast chromatographic separation. Method validation confirmed excellent performance in specificity, linearity, precision, accuracy, and stability. Furthermore, the method’s greenness and practicality were quantitatively superior to a conventional approach, as evidenced by higher scores in sustainability assessments. Application to market samples revealed a notable disparity: Antibiotic residues were frequently detected in bear bile powder, while none were found in biotransformed bear bile powder. These findings furnish a reliable analytical tool for quality control and highlight biotransformed bear bile powder as a safer alternative, underscoring the impact of production practices on product safety.
Polyphenylene sulfide (PPS) chopsticks are valued for their heat resistance; however, food-contact safety research has predominantly focused on common plastics such as polyethylene and polypropylene, neglecting the effect of cooking conditions on specialty plastics. This study aimed to systematically investigate the release of dichlorobenzene (DCB) isomers (1,2-, 1,3-, and 1,4-DCB) from PPS chopsticks at cooking temperatures. Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FESEM) confirmed polymer matrix integrity and revealed surface oxidation at 160 degrees C and micro-cracks at 200 degrees C, elucidating pathways for DCB migration. A three-dimensional (3D) response-surface-optimized high-performance liquid chromatographic (HPLC) method afforded a limit of detection (LOD) of 0.05 mg L-1 and a limit of quantification (LOQ) of 0.15 mg L-1 for each isomer, with a correlation coefficient of > 0.999, recovery of > 90%, and intraday precision of < 2%. Olive-oil simulant tests (175 degrees C, 2 h) detected 1,4-DCB in 4 of 14 new batches, challenging the "200 degrees C-safe" claim and underscoring the need for batch-specific verification. Our findings provide the first systematic evidence of DCB migration from PPS tableware, providing a rigorous analytical framework to improve food-contact material safety and inform regulatory standards for developing heat-resistant plastics.
