Gas Chromatography Research Articles (Page 1)

This study investigated the chemical and biological properties of hydroethanolic extracts from Solanum asperum, Solanum crinitum, Solanum schlechtendalianum, Solanum stramoniifolium, and Solanum leucocarpon. Using ultra-high-performance liquid chromatography with electrospray ionization mass spectrometry and gas chromatography, 41 compounds and five monosaccharides were identified. Antioxidant activity was confirmed in all extracts through the DPPH radical scavenging assay, with S. schlechtendalianum showing the highest activity, consistent with its elevated total polyphenol (94.4mgGAE/g) and flavonoid (46.8mgQE/g) contents. The anticancer potential was assessed against human breast (MCF-7, MDA-MB-231) and colorectal (HRT-18) cancer cell lines using the MTT assay. Among the samples, S. crinitum exhibited the greatest cytotoxicity against HRT-18 cells, with an IC50 of 58µg/mL and a selectivity index of 1.5, confirmed by clonogenic assays. Furthermore, S. crinitum significantly inhibited nitric oxide production (74%), cell migration (74%), and adhesion (52% and 30% on fibronectin and vitronectin, respectively), indicating notable anti-metastatic potential. These results demonstrate that Solanum species, particularly S. crinitum and S. schlechtendalianum, are promising sources of bioactive compounds with antioxidant, anticancer, and anti-metastatic properties, supporting their potential use in pharmaceutical and cosmetic industries.

This study introduces a novel and environmentally relevant sample preparation strategy for the trace-level determination of hazardous phenolic pollutants in complex wastewater matrices. Unlike conventional extraction methods that merely tolerate matrix interferences, this approach eliminates them before analyte extraction, improving selectivity and reliability. A magnetic core-shell metal-organic framework was employed to selectively adsorb interfering substances from real wastewater samples collected from pharmaceutical, municipal, and petrochemical sources. This material was characterized using scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, and Brunauer-Emmett-Teller surface analysis. Its magnetic responsiveness allowed for simple and rapid phase separation without the need for centrifugation. Following matrix cleanup, phenolic compounds were derivatized using acetic anhydride in the presence of sodium carbonate and extracted using a vortex-assisted liquid-liquid microextraction technique. The optimized method required minimal amounts of sorbent and organic solvents, improving its environmental sustainability and reducing laboratory waste. Coupled with gas chromatography and flame ionization detection, the method demonstrated excellent analytical performance, with relative standard deviations between 1.0 and 8.3% (for 10 µg L⁻1), recoveries ranging from 62 to 83%, correlation coefficients above 0.9962, and low limits of detection and quantification. Application to real wastewater samples showed recoveries between 81 and 118%, confirming the method's effectiveness in eliminating matrix interferences and accurately determining phenolic pollutants.

Effects of the 2023 Poole Harbour oil spill on sediment bacterial communities and ecosystem functioning.

In recent years, the issue of drivers under the influence of medications and psychoactive substances as a cause of road accidents has gained increasing importance. This study aimed to assess the prevalence and blood concentration ranges of alcohol and psychoactive substances among drivers in northeastern Poland between 2013 and 2024. To determine the prevalence of medications and psychoactive substances in drivers’ blood, data were collected from 266 blood samples obtained from drivers (251 men and 15 women). Among these, 79 drivers died immediately, 61 drivers survived the accident, and 126 drivers were stopped for roadside checks. The presence of the studied substances was confirmed using gas chromatography combined with mass spectrometry detection (GC-MS) and liquid chromatography combined with mass spectrometry detection (LC-MS). Blood alcohol content was measured using headspace gas chromatography with a flame ionisation detector (HS-GC-FID). Psychoactive substances were detected in 152 of the 266 samples. Drivers testing positive for medications and psychoactive substances were most frequently stopped during roadside controls—67.46%. Among the total positive cases, psychoactive substances used alone or in combination included THC—46.3% (range 0.2–20 ng/mL), alcohol—26.8% (range 0.1–4.1‰), amphetamines—20.7% (range 15–2997 ng/mL), opiates—4.3% (morphine 66.0 ng/mL; methadone 174.0 ng/mL; ranges: tramadol 15.0–600.0 ng/mL; fentanyl 45.0–100.0 ng/mL), benzodiazepines—9.8% (ranges: diazepam 55.0–480.0 ng/mL; midazolam 17.0–1200.0 ng/mL; clonazepam 21.0–36.0 ng/mL), stimulants—6.10% (ranges: amphetamine 15.0–2997.0 ng/mL; cocaine 4.0–30.0 ng/mL; benzoylecgonine 38.0–602.0 ng/mL; PMMA 45.0–360.0 ng/mL; MDMA 20.0–75.0 ng/mL; mephedrone 37.5 ng/mL; alfa-PVP 120 ng/mL), psychotropic drugs—3.1% (carbamazepine 8.0–2100.0 ng/mL; zolpidem 233.0 ng/mL; citalopram 320.0 ng/mL; opipramol 220 ng/mL). The most commonly used substance among car and motorcycle drivers was THC (37.7% of car drivers and 60% of motorcyclists). Among operators of other types of vehicles, alcohol was the most frequently detected substance, present in 35% of cases. The majority of drivers (81.1%) were under the influence of a single substance. Among the drivers, 7.3% consumed alcohol in combination with at least one other substance, and 11.6% used two or more substances excluding alcohol. Among the psychoactive substances most frequently used alone or in combination with others, THC was predominant. Roadside testing, based on effects similar to alcohol intoxication, was mainly conducted on male drivers.

Microplastics (MPs) are a ubiquitous marine pollutant, and their presence in bivalves is receiving increasing attention due to the associated risks to human health. The steps of pretreatment, detection, and quantification in the analysis of MPs depend on the type of polymer. Research on MPs is challenging because of the varying characteristics of these materials, such as the size, shape, and polymer type. Consequently, there are no standardized methods for their collection, separation, identification, or quantification. This review specifically examines the available bivalve digestion steps, focusing on efficient and time-reducing methods, such as the microwave-assisted (MAW) procedure and its advantages. Recent achievements in the application of pyrolysis gas chromatography–mass spectrometry (Pyr-GC-MS) are presented for the profiling of polymer mass-related microplastics data in marine bivalves. Here, we provide an overview of the abundance, properties, and polymer types of MPs in bivalve species, highlighting the polymer mass fractions. To date, the available mass-based concentrations have revealed nine types of MPs—polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polystyrene (PS), polymethyl methacrylate (PMMA), polyamide 66 (PA66), polycarbonate (PC), and polyamide 6 (PA6)—with PE, PP, and PVC being the most common. The total MP levels in bivalves were at ppm levels, ranging from 0.26 µg/g to 36.4 µg/g wet weight. The risk of human ingestion of MPs was assessed through the consumption of bivalves as seafood. The overall potential human health risk value (H) for marine bivalves was classified within the moderate to high hazard category.

This study explored the potential of bacterial consortia to remediate real diesel-contaminated agricultural soils. Two consortia were tested: a native consortium isolated from contaminated soil and an exogenous consortium derived from vermicompost. Bacterial communities (consortia and soils) were characterized through high-throughput sequencing. Within 30 days, total petroleum hydrocarbons (TPH) were removed most efficiently by bioaugmentation with the native consortium (53.32%), followed by the exogenous vermicompost consortium (47.14%) and the indigenous microbiota (42.52%). Gas chromatography confirmed the reduction of polycyclic aromatic hydrocarbons (PAHs) with 2–5 rings; however, terphenyl, chrysene, and pyrene persisted. The highest TPH biodegradation rate was observed in the treatment inoculated with the native consortium (208.5 mg/kg per day), followed by the treatment with indigenous microbiota (181.8 mg/kg per day) and the exogenous consortium (161.9 mg/kg per day). Furthermore, hydrocarbon-degrading bacterial populations increased significantly during the first week but declined after day 21, showing a negative correlation with TPH concentrations across all treatments, indicating that the highest bacterial activity and degradation occurred during the first 14 days. Taxonomic analysis identified Actinobacteria as the most abundant phylum in the initial soil, whereas Proteobacteria dominated both the consortia and the bioremediated soils. Significant differences in community structure and composition were observed between the consortia according to their origin, influencing removal efficiency. Dominant genera shifted from Nocardioides and Streptomyces in untreated soil to Pseudomonas, Sphingobium, and Pseudoxanthomonas following biological treatments, while Nocardia, Rhodococcus, and Bacillus remained nearly constant. These findings underscore the effectiveness of adapted bacterial consortia in restoring real diesel-contaminated agricultural soils and highlight potential microbial succession patterns associated with biodegradation and soil ecological recovery.

Chia (Salvia hispanica L.) seed oil, the richest vegetable source of α-linolenic acid (omega-3), faces challenges in food applications due to its hydrophobicity and susceptibility to oxidation. Encapsulation technologies are therefore required to deliver this bioactive compound, with amylose inclusion complexes emerging as promising systems. This study investigated the potential of amylose inclusion complexes as delivery systems for α-linolenic acid from chia seed oil in a real food matrix. These complexes were incorporated into an instant soup, and their in vitro digestibility was assessed using the INFOGEST 2.0 protocol. Gas chromatography analysis confirmed a significant increase in the omega-3 content of soups through the addition of inclusion complexes, and this bioactive compound showed high stability during the soup preparation. After in vitro digestion, approximately 20% of α-linolenic acid was released from the complexes, which was not significantly influenced by the soup matrix. Monitoring of maltose released during starch degradation indicated that the complexes remained stable under gastric conditions, achieving selective degradation in the intestinal phase. These findings highlight amylose complexes as promising carriers for protecting and delivering omega-3 from chia oil in instant soups, contributing to the development of functional foods and the valorization of the chia crop.

The electrochemical oxidation mechanism of biopolymer lignin is challenging to characterize due to its complex structure. Controlling the oxidation process is crucial for ensuring the economic feasibility of electrochemical depolymerization of lignin, as it often generates numerous undesirable compounds. Regulating the depolymerization process can lead to the production of high-yield aromatic compounds, such as phenols and carboxylic acids. In addition to the depolymerization of lignin by the electrocatalyst, hydroxyl radicals (•OH) during the electrochemical oxidation could also depolymerize lignin. Previous studies have reported that •OH forms during electrochemical oxidation; however, it is still uncertain whether these radicals or electrocatalysts are responsible for depolymerizing lignin. This study investigates the pivotal issue of whether the depolymerization process is driven by •OH or by a direct electrochemical route. In this study, lignin compounds were electrochemically oxidized using a nickel-cobalt (Ni-Co) electrocatalyst at several electrode potentials, and the oxidized products were analyzed using headspace solid-phase micro-extraction gas chromatography–mass spectrometry (SPME-GC-MS) and factor analysis (FA). Electrochemical depolymerization of lignin yielded mainly phenolic compounds (e.g., tert-butyl phenols), phthalate esters (e.g., dibutyl phthalate, bis(2-methylpropyl) phthalate), furan derivatives (e.g., 2-butyltetrahydrofuran), and short-chain carboxylic acid esters. This work has successfully predicted that both electrocatalyst and •OH radicals contribute to the electrochemical depolymerization of lignin. Radical-mediated depolymerization yielded a broader range of products.

Background: The search for environmentally friendly antifouling agents has led to an increased focus on marine natural products. Methods: This study investigated the antifouling potential of lipid fractions extracted from ten marine fungal strains isolated from the Beibu Gulf, China. The lipids were evaluated through a multi-level bioassay approach, including the inhibition of microfouling (against four fouling bacteria: Marinobacterium jannaschii, Vibrio pelagius, Vibrio rotiferianus, and Alteromonas macleodii), the prevention of macrofouling (inhibition of barnacle Amphibalanus reticulatus cyprid settlement), and long-term (90-day) marine field trials. Results: Eight lipid fractions demonstrated inhibitory effects against at least one bacterial strain. Five lipids significantly inhibited barnacle cyprid settlement, with half-maximal effective concentration (EC50) values ranging from 0.21 to 1.81 µg/mL and exhibited low toxicity (half-maximal lethal concentration (LC50) > 50 µg/mL). Notably, four lipid fractions maintained potent antifouling efficacy (>70% inhibition) throughout the 90-day field exposure. Chemical characterization via gas chromatography–mass spectrometry (GC–MS) revealed that the bioactive fractions were predominantly composed of fatty acids and their derivatives. Major identified compounds included palmitic acid, methyl palmitate, linoleic acid, dodecyl-9-ynyl chloroacetate, cis-13-octadecenoic acid, oleic acid, methyl 11,14-octadecadienoate, and (E)-9-octadecenoic acid methyl ester. Conclusions: This work represents the first comprehensive investigation of marine fungal lipids from the Beibu Gulf with multi-target antifouling properties, providing a theoretical foundation and practical candidate compounds for developing eco-friendly antifouling coatings.

Introduction: Pongamia pinnata, commonly known as the Indian Beech tree, has been traditionally used in various medicinal systems for its therapeutic properties. The seeds of Pongamia pinnata are particularly noted for their bioactive compounds, which have shown potential in treating a range of ailments. However, a comprehensive quantitative analysis of these extracts remains underexplored. Methods: Pongamia pinnata seeds were collected and processed to obtain extracts using ethanol. The extracts were subjected to phytochemical screening to identify and quantify key bioactive compounds such as flavonoids, alkaloids, saponins, and phenolic compounds. Gas chromatography- mass spectrometry (GC-MS) was employed to precisely quantify these constituents. Results: The quantitative analysis revealed significant levels of flavonoids and phenolic compounds in the ethanolic extracts. Alkaloids and saponins were also detected in notable quantities. GC-MS confirmed the presence of compounds such as karanjin, pongamol, and karanjachromene. Discussion: The GC-MS analysis of Pongamia pinnata seed extracts revealed diverse bioactive compounds, including fatty acids, esters, and sterols, supporting its pharmacological potential. The advanced technique enabled precise identification and quantification of both major and minor constituents, providing a robust chemical fingerprint. Conclusion: The quantitative analysis of Pongamia pinnata seed extracts underscores their rich phytochemical profile and significant pharmacological potential. The high content of bioactive compounds, particularly flavonoids and phenolics, aligns with the traditional uses of Pongamia pinnata in herbal medicine. These findings need further investigation into the therapeutic applications of these extracts, particularly in developing novel treatments for oxidative stress-related diseases and microbial infections.

Vapor pressures of eight aliphatic hexanols ((±)-3-hexanol, CAS RN: 623-37-0; 2-methyl-2-pentanol, CAS RN: 590-36-3; (±)-2-methyl-3-pentanol, CAS RN: 565-67-3; (±)-3-methyl-2-pentanol, CAS RN: 565-60-6; 3-methyl-3-pentanol, CAS RN: 77-74-7; 2,2-dimethyl-1-butanol, CAS RN: 1185-33-7; 2,3-dimethyl-2-butanol, CAS RN: 594-60-5; and (±)-3,3-dimethyl-2-butanol, CAS RN: 464-07-3) were measured by the static method in the temperature range of 233 to 308 K. These data were combined with selected literature vapor pressures and simultaneously correlated with heat capacities in the ideal gaseous state (determined in the framework of this work, since no literature data were available) and liquid heat capacities reported by us previously. The vapor pressures measured for test (px) and reference (pr) compounds were combined with corresponding gas–liquid chromatographic (GLC) adjusted retention times (t′) measured in the same temperature region to determine relative activity coefficients at infinite dilution (γrel∞). The linearly extrapolated values of γrel∞ up to 363 K, together with known directly measured pr values at these temperatures, allow reasonably accurate px data to be obtained at extrapolated temperatures. Results were compared with fragmentary literature data. Enthalpies of vaporization derived from the vapor pressures obtained in this work represent a significant contribution to existing databases.

Membrane dialysis is a suitable technique for the partial dealcoholization of wines that preserves most of the aromas of the original wine. In this study this technique has been used to compare white and red wines of the same vintage. The results of partial dealcoholization have been checked in terms of chemical and sensory properties. In addition, gas chromatography was carried out to determine whether the aromas are appreciably diminished in their final composition for filtered wines. Membrane dialysis resulted in wines with a lower alcoholic strength than the starting one, 11.0 g/kg alcohol reduction was obtained for white wines and 13.4 g/kg for red wines after dialysis, and with acceptable chemical and sensory characteristics but with a lower concentration of some aromatic compounds. This partial dealcoholization technique is slightly more effective for the treated red wines. However, the dialyzed red wines are less acceptable by consumers than the corresponding white wines. © 2025 Society of Chemical Industry.

Background: Exhaled volatile organic compounds (VOCs) can provide insight into various physiological and metabolic processes. Aim: The purpose of this study was to determine if exhaled VOCs would differ across disease severity in heart failure (HF) patients. Methods: We recruited 62 individuals who were classified as healthy control (CTL), admissions with fluid overload (DHF), NYHA class I-II or NYHA class II-III. Breath samples were collected using the ReCIVA Breath Sampler (Owlstone Medical Ltd) and analyzed using mass spectrometry and gas chromatography. Typical clinical characteristics were documented at the time of exhaled breath collection. Results: Data were obtained on 16 CTL, 21 DHF, 15 NYHA I-II and 10 NYHA II-III (characteristics shown in Table). For the HF groups, DHF, NYHA I-II and NYHA II-III, the %HPEFF were 32, 63 and 63% respectively. Regarding exhaled VOCs, we observed a stepwise increase in VOCs potentially linked to lipid peroxidation or fatty acid metabolism, such as pent-3-en-2-one, 2-pentanone, and 4-heptanone, as disease severity worsened. A similar trend was seen for sulphur containing compounds (methyl propyl sulfide, allyl methyl sulfide and 1(methyl thiol)-1 propene)), potentially providing insight into impaired hepatic or renal clearance in more advanced HF. The level of methyl pyruvate on breath also rose with increasing disease severity, which may reflect altered energy metabolism. Finally, gut microbiome-related VOCs (acetoin, 2,3-butanediol, and butyric anhydride) increased across severity groups, potentially reflecting dysbiosis in advanced disease. Conclusions: In a small pilot study aiming to identify potential exhaled breath biomarkers in HF, we observed significant differences in VOCs across disease severity. These compounds have been linked to lipid peroxidation, energy metabolism, liver and kidney function as well as microbial fermentation and short-chain fatty acid metabolism. Collectively, these data demonstrate the ability of breath omics to potentially stratify disease severity and provide additional biological insights into HF pathophysiology. Larger studies are needed to determine whether a breath biomarker panel could be established to quantify disease severity and predict decompensation risk in HF.

Abstract Complete uncoated extruded kibble was coated with a premium chicken fat spiked with 0, 5, 10, 15, or 20 percent free fatty acids (Oleic acid, Millipore Sigma. Burlington, MA), and 3% liquid chicken-based natural flavor. Kibbles were then utilized in oral palatability (20 dogs, 10 m/10F), aromatic palatability (20 dogs, 10M/10F), and apparent total tract digestibility (36 dogs, 18M/18F). Kibble odors were analyzed by flash gas chromatography electronic nose (AlphaMOS, Toulouse, France), and SPME GC/q-TOF (MUMC, Columbia, MO). In the aromatic palatability trials, there were no significant differences in first approach (P ≥ 0.21), percent interaction time (P ≥ 0.16), or interaction ratio (P ≥ 0.94). In the oral palatability trials, there were no significant differences in first approach (P ≥ 0.26), first bite (P ≥ 0.50), percent consumed (P ≥ 0.15), or intake ratio (P ≥ 0.59). There was no significant difference in protein, carbohydrate, or dry matter digestibility (P ≥ 0.06), and no significant difference in fat digestibility between coated diets by Tukey’s post hoc (P ≥ 0.09). Principle component analysis of e-nose peaks showed minimal odor changes between samples (DI=-3). Volatile analysis identified 16 compounds correlated with oleic acid percentage (r2 ≥ 0.50). Kibble coated with chicken fat containing up to 20% oleic acid did not negatively impact odor profile or palatability in Labrador retrievers.

Abstract. Light-absorbing organic carbon, collectively known as brown carbon (BrC), significantly influences climate and air quality, particularly in urban environments like Dhaka, Bangladesh. Despite their significance, the contributions and transformation pathways of phenolic compounds – major precursors of brown carbon (BrC) – are still insufficiently understood in the South Asian megacities. This study addresses this gap by investigating the surface morphology of PM2.5, quantifying seven phenolic BrC precursors, and exploring the aqueous-phase formation pathway of nitrophenols at two urban sites (Dhaka South and Dhaka North) from July 2023 to January 2024. Phenolic compounds, including phenol, methylphenols, methoxyphenol, hydroxyphenol, and nitrophenol were identified and quantified using gas chromatography–flame ionization detector (GC-FID). PM2.5 surface morphology and elemental composition were analyzed via Field Emission Scanning Electron Microscopy – Energy Dispersive X-ray Spectroscopy (FESEM-EDX), and functional groups were characterized using Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR). Results revealed that PM2.5 particles were predominantly spherical or chain-like with carbonaceous elements (C, O, N, S), mineral dust, and trace metals. The dominant functional groups included aromatic conjugate double bond, carbonyl, and nitro group. Aqueous-phase nitration of 2-hydroxyphenol under acidic conditions, analyzed via UV-Vis spectroscopy, demonstrated an alternative nitrophenol formation pathway. Among the detected compounds, 2-hydroxyphenol and 4-nitrophenol showed the highest average concentrations (2.31 ± 1.39 and 2.20 ± 1.21 µg m−3, respectively). Seasonal variations showed elevated nitrophenol levels during winter, especially in Dhaka South (4.54 ± 2.94 µg m−3). These findings highlight the quantification of phenolic precursors and the role of aqueous-phase reactions in BrC formation, providing valuable insights for future atmospheric modeling and air quality management strategies in South Asia.

Background: Exposure to cyclohexanone, an industrial solvent used to soften medical plastics, has been associated with unfavorable outcomes for neonates undergoing congenital heart surgery. Yet, the underlying physiologic mechanisms remain unclear. Hypothesis: Cyclohexanone exposure induces a systemic inflammatory response following cardiopulmonary bypass (CPB) in neonates undergoing congenital heart surgery. Methods: We analyzed data from 70 neonates enrolled in the placebo group of the Corticosteroid Therapy in Neonates Undergoing Cardiopulmonary Bypass trial. Serum samples were collected at five time points: preoperatively, immediately after CPB cessation, and at 4, 12, and 24 hours postoperation. Serum cyclohexanone and cytokine concentrations were measured using gas chromatography tandem mass spectrometry and multiplex enzyme-linked immunoassays, respectively. We used covariate-adjusted longitudinal quantile regression to separately estimate the expected differences in 75 th percentile cytokine concentrations (and 95% CIs) per interquartile range (IQR) increase in preoperation serum cyclohexanone concentration as well as contemporaneous, perioperative cyclohexanone concentrations. Covariates included age and weight at surgery, STAT mortality risk category, cytokine assay batch, and total CPB duration. Results: In covariate-adjusted models, an IQR increase in preoperation cyclohexanone concentration was associated with a 342.3 pg/mL (-460.0, -224.5) lower IL-10 concentration at 4 hours postoperation, 330.3 pg/mL (185.8, 474.8) higher IL-6 concentration at 4 hours and 438.2 pg/mL (37.9, 838.4) higher concentration at 12 hours postoperation, and 64.9 pg/mL (13.4, 116.5) higher IL-8 at 12 hours postoperation. An IQR increase in contemporaneous cyclohexanone concentration was associated with lower IL-10 levels after CPB cessation (-997 pg/mL; 95%CI: -1545, -449), whereas IL-8 was significantly higher after CPB cessation (83 pg/mL; 95%CI: 4.64, 161) and 4 hours (250 pg/mL; 95%CI: 95.3, 405), 12 hours (35.6 pg/mL; 95%CI: 12.1, 59.1), and 24 hours (77.3 pg/mL; 95%CI: 24.9, 130) postoperation. Conclusions: Perioperative cyclohexanone exposure is associated with a proinflammatory response. These results suggest that cyclohexanone may contribute to postoperative inflammation following CPB and further potentiate adverse postoperative outcomes. Further studies are needed to develop strategies to reduce cyclohexanone exposure in the perioperative environment.

Background: Antimicrobial resistance in oral pathogens drives interest in natural alternatives such as essential oils (EOs). Methods: The chemical composition and in vitro antimicrobial activity of Origanum vulgare, Thymus vulgaris, and Lavandula angustifolia EOs were investigated. Oils were profiled by gas chromatography–mass spectrometry (GC-MS) and tested against Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 using the disc diffusion method (triplicate, 1 µL/disc, ~850–950 µg). Results: O. vulgare oil produced the strongest inhibition against C. albicans (18.4 ± 0.5 mm), T. vulgaris was most active E. coli (13.0 ± 0.5 mm), while L. angustifolia showed negligible activity (6–7 mm). All EO inhibition zones were smaller than those of antibiotics. Conclusions: At clinically relevant doses, Oregano and Thyme oils showed modest antimicrobial effects, whereas Lavender was inactive. However, these findings are limited by the use of ATCC strains, small sample size, and reliance on the disc diffusion method, which provides only qualitative data and does not capture biofilm or host interactions. Future studies should include minimum inhibitory concentrations (MIC)/minimum bactericidal concentrations (MBC) assays, biofilm models, and cytotoxicity testing. AI-assisted GC-MS analysis and automated inhibition zone measurement should be considered as future perspectives to improve reproducibility and translational potential.

This study aimed to achieve efficient capture of phthalate esters (PAEs) and bisphenol A (BPA) from pear samples collected in the northern Anhui Province. A novel polystyrene–pyridine (PS/PD) composite nanofiber membrane was fabricated via electrospinning and employed as a filter in the sampling process. Following sample collection, PAEs and BPA were extracted with acetonitrile (ACN). Then, 100 μL of the extract was further concentrated using packed-fiber solid-phase extraction (PFSPE), with PS/PD nanofibers as the sorbent, and subsequently analyzed by gas chromatography–mass spectrometry (GC-MS). Under the optimized procedure, satisfactory recoveries of 87.0–109.9% were obtained for pear samples, with relative standard deviations (RSDs) ranging from 0.6% to 11.9%. Limits of detection (LOD) and limits of quantification (LOQ) were 0.03–0.10 μg/L and 0.034–0.34 μg/L, respectively. Analysis of pear samples from local markets and the native region was performed, and the detected concentrations of five PAEs and BPA ranged from 0.037 to 0.079 μg/L. Matrix effects were also evaluated. These findings demonstrate that the developed packed-nanofiber solid-phase extraction (PFSPE)-GC-MS method is reliable and effective for the determination of PAEs and BPA in pear samples.

Abstract Rice cultivation is a significant source of agricultural methane (CH₄), yet routine quantification still relies heavily on gas chromatography (GC), which limits throughput and field deployment. Here, we evaluated a portable tunable-diode-laser absorption spectroscopy (TDLAS) detector (PMD) as an alternative to GC for measuring CH₄ released from pot-grown rice plants under field conditions. Weekly closed-chamber samples from five cultivars were analyzed in parallel by GC (FID/MS) and the PMD. Standard gas tests showed an excellent linear relationship for the PMD (R 2 = 0.9995), indicating a near-ideal response. Across field samples, GC and PMD were strongly associated (R 2 = 0.9943). Bland–Altman analysis revealed a mean bias (GC − PMD) of 8.55 with 95% limits of agreement − 9.16 to 26.26, and Lin’s concordance correlation coefficient was 0.991, evidencing near-perfect agreement despite a slight systematic offset. A simple calibration with a linear regression eliminated the bias and narrowed the limits of agreement, while preserving the high correlation. Residual analyses suggested a modest influence of CO₂ (but not N₂O) on between-method differences. Taken together, the PMD provides rapid, robust, and labor-efficient CH₄ measurements that closely match GC when a fixed calibration is applied, enabling high-throughput phenotyping of rice genotypes and management practices in both laboratory and field settings. This calibrated, portable approach lowers barriers to large-scale screening for low-emission rice, supporting climate-smart crop improvement.

Arbuscular mycorrhizal symbiosis (AMS) is a ubiquitous mutualistic interaction between many terrestrial plants and fungi, with lipids playing a pivotal role in nutrient exchange. However, few genetic regulators of AMS have been functionally validated in tomato. To investigate candidate genes, we employed CRISPR-Cas9 and VIGS to generate knockout and knockdown lines. A comprehensive suite of molecular biology techniques, including yeast-1/2-hybridization, BiFC, ChIP-qPCR, and RNA-sequencing, was used to elucidate the regulatory roles of SlWRI5a, SlHY5, and SlFatM in fatty acid (FA) biosynthesis and AMS in tomato. FA composition was analyzed using gas chromatography. In this study, we validated SlWRI5a and SlFatM as key regulators of 16-carbon FA biosynthesis during AMS in tomato and demonstrated physical interactions between SlWRI5a and SlHY5. SlHY5 expression was induced by AMS and promoted root FA biosynthesis. Finally, we demonstrated that SlWRI5a and SlHY5 can co-regulate SlFatM-mediated FA accumulation, thereby influencing AMF colonization efficiency in tomato. Our findings reveal the SlWRI5a/SlHY5-SlFatM regulatory module, offering new insights into lipid-mediated AMS in tomato. This work also highlights a novel role for HY5 during fungal symbiosis, underscoring its broader significance in plant-microbe interactions.