Search Results (158)

In this study, an ultrasound-assisted extraction (UAE) method combined with ion chromatography (IC) was developed, optimized and validated for the determination of benzoate in Northern Thai green chili dip. Four extraction variables were optimized using response surface methodology (RSM) based on a Box–Behnken design (BBD). The optimal conditions were a sample mass of 5.0 g, water volume of 20.0 mL, extraction temperature of 70 °C, and extraction time of 20 min. The validated method showed good linearity in the range of 0.5 to 100 mg L⁻¹, limits of detection (LOD) and quantification (LOQ) of 0.305 and 1.070 mg L⁻¹, respectively, precision in the range of 0.31 to 6.37% (%RSD, n = 11), and spiked recovery in the range of 85.50 to 107.80%, all of which were within the acceptable criteria. The AGREE score of the developed method was 0.45, which was higher than that of the conventional LLE-HPLC-UV method (0.27) due to the use of only deionized water as the extracting solvent and no generation of organic waste. The developed method was sensitive, validated, and environmentally friendly, and was successfully applied to the determination of benzoate in traditional condiment products. The proposed method may serve as an alternative approach for routine food analysis and quality control. Full article

Background/Objectives: Lavandula cariensis species is cultivated uncommonly in the western region of Turkey. The colloquial appellations avayianos, karabasi, and myra are used to refer to the L. cariensis plant. The essential oil of L. cariensis was studied for its potential antiglaucoma, antioxidant, antidiabetic, and acetylcholinesterase inhibitory effects. Methods: The inhibitory effect of the essential oil of L. cariensis on the acetylcholinesterase (AChE), carbonic anhydrase II (CA II), and α-amylase enzymes was determined. Therefore, chemical profiles of L. cariensis’ essential oil were identified using Gas Chromatography Mass Spectrometry (GC-MS) and as Chromatography with Flame Ionization Detection (GC-FID) analyses. Results: Camphor (39.73%), fenchone (19.49%), exobornyl acetate (6.81%), camphene (5.49%), and eucalyptol (5.49%) were the most abundant compounds in L. cariensis essential oil. Radical scavenging effect of the essential oil of L. cariensis was examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) (IC₅₀: 231.0 ± 0.094 μg/mL) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) (IC₅₀: 7.45 ± 0.013 μg/mL) radicals. Also, the ferric ions (Fe³⁺), cupric ions (Cu²⁺), and Fe³⁺-2,4,6-tri(2-pyridyl)-S-triazine (TPTZ) complex reducing capabilities were studied. Additionally, essential oil of L. cariensis indicated a comparable level of inhibition towards hCA II (IC₅₀: 276.42 μg/mL), AChE (IC₅₀: 14.22 μg/mL), and α-amylase (IC₅₀: 475.63 μg/mL) enzymes. Conclusions: The evaluation of the antioxidant capabilities and enzyme inhibition profiling of the essential oil of L. cariensis will be made possible by this comprehensive study, which serves as a springboard for further research. The essential oil of L. cariensis demonstrated enzyme-inhibitory activities against target enzymes associated with Alzheimer’s disease, diabetes, and glaucoma. Also, this study’s in vitro inhibition suggests promising prospects. Full article

A multi-analytical investigation was carried out to elucidate the deterioration processes affecting the stone materials of the Arca di Cansignorio della Scala in Verona (Italy) and to characterize the surviving traces of its original polychrome and gilded decoration. The study combined macroscopic mapping, stratigraphic sampling, optical microscopy (OM), environmental scanning electron microscopy coupled with energy-dispersive X ray spectroscopy (ESEM-EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and ion chromatography (IC). The monument, predominantly carved from Candoglia marble, exhibits three principal weathering patterns: (i) rain washed areas affected by marble decohesion, (ii) grey deposits corresponding to dirt accumulation areas; and (iii) sulphation-induced black crusts developed in dirt wetting areas. In addition, severe mechanical deterioration was found to be associated with early twentieth-century structural consolidation interventions involving embedded iron bars, whose corrosion-driven volumetric expansion generated vertical cracking. Stratigraphic and microanalytical investigations revealed the presence of original azurite-based polychromy, proteinaceous and lipidic binding media, lead white preparatory layers, and multiple applications of gold leaf. The analytical results highlight the complex interplay between environmental exposure, atmospheric pollution, the incompatibility of materials introduced during past restorations campaigns. Furthermore, they contribute to a better understanding of the composition, execution techniques and preservation state of the surviving decorative layers, providing a scientific basis for future conservation strategies. Full article

Picnomon acarna (L.) Cass. is a Mediterranean medicinal plant with limited phytochemical and bioactivity characterisation. In this study, methanolic extracts obtained by maceration (MAC), Soxhlet (SOE), and ultrasound-assisted extraction (UAE) were comparatively investigated to determine their phytochemical composition and biological potential. Liquid chromatography–electrospray ionisation–tandem mass spectrometry (LC–ESI–MS/MS) analysis identified and quantified 24 phenolic compounds, with hesperidin, chlorogenic acid, and hyperoside as the dominant constituents. The maceration extract exhibited the highest total phenolic content (29.06 mg GAE/g extract) and showed superior antioxidant performance across six complementary assays [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), phosphomolybdenum, and ferrous-ion chelation), reflected by the highest relative antioxidant capacity index (RACI = 0.93). Enzyme inhibition assays revealed extraction-dependent activity patterns: Soxhlet and ultrasound extracts demonstrated stronger acetylcholinesterase inhibition (IC₅₀ ≈ 1.23 mg/mL), while Soxhlet extract showed the most potent tyrosinase (AChE) inhibition (IC₅₀ = 1.48 mg/mL). α-Amylase inhibition was comparable among extracts (IC₅₀ = 1.90–2.03 mg/mL). Pearson correlation analysis indicated strong relationships between major phenolics and antioxidant activity. Molecular docking further supported these findings, showing favourable binding affinities of hesperidin, hyperoside, and chlorogenic acid toward α-amylase and acetylcholinesterase, while only chlorogenic acid and hyperoside demonstrated favourable interactions with tyrosinase-related protein-1 (TYRP1), whereas hesperidin did not exhibit a meaningful binding affinity. Overall, the results demonstrate that the extraction strategy significantly influences the phenolic composition and multi-target bioactivity of P. acarna, highlighting its potential as a source of natural antioxidant and enzyme-modulating compounds. Full article

In the present work, the blackening process of Panax quinquefolius L. (PQ) was systematically investigated at temperatures of 70–90 °C, relative humidities (RHs) of 70–85%, and treatment times of 0–14 days. Ginsenoside compositions and transformation pathways were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography coupled with ion trap time-of-flight tandem mass spectrometry (LC-IT-TOF-MS/MS). The results demonstrated that blackening treatment significantly increased total saponin content from 2.72% to 5.73% after being treated at 80 °C and 70% RH for 12 days, accompanied by the highest conversion efficiencies for newly generated ginsenosides Rk1 (8.89 mg/g) and Rg5 (17.69 mg/g). Furthermore, compared with untreated PQ saponins (PQS), the blackened PQ saponins treated under optimal conditions (BPQS) exhibited superior 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation (ABTS⁺) radical scavenging activities, with IC₅₀ values of 0.2999 mg/mL and 0.2640 mg/mL, respectively, as well as stronger reducing power. Meanwhile, BPQS exhibited higher cytotoxicity toward HepG2 cells and effectively inhibited cell survival and proliferation by promoting the expression of apoptosis-related proteins, including caspase 3 and caspase 9. Our findings indicate that BPQS may be a functional ingredient suitable for use in dietary supplements and disease chemoprevention. Full article

In this study, the Box–Behnken Design (BBD) was adopted to optimize the ultrasound-assisted extraction (UAE) conditions of polyphenols from Hericium erinaceus (H. erinaceus) on the basis of single-factor experiments, with extraction time, solid–liquid ratio and ethanol concentration as the key investigation factors. The optimal extraction parameters were determined as follows: extraction time of 56.85 min, solid–liquid ratio of 1:56.71 g/mL and ethanol concentration of 44.64%, under which the actual yield of the total polyphenol crude extract (TPCE) reached 0.9985 ± 0.03%, which was highly consistent with the theoretical predicted value of 0.9960%, verifying the good fitting degree of the established model. Taking L-ascorbic acid as the positive control, the antioxidant activity of TPCE was evaluated by determining its scavenging capacity against ABTS·⁺, ·OH and DPPH· free radicals, and the half-maximal effective concentration (EC₅₀) values were measured to be 0.8850, 0.9490 and 4.198 mg/mL, respectively. With acarbose as the reference drug, the inhibitory effects of TPCE on α-amylase and α-glucosidase related to carbohydrate metabolism were assayed, and the corresponding half-maximal inhibitory concentration (IC₅₀) values were 0.0135 and 130.3 mg/mL, respectively. Furthermore, ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was employed for the tentative identification of bioactive components in TPCE, and a total of 48 and 64 chemical constituents were characterized in negative and positive ion modes, respectively, providing a chemical basis for the biological activities of TPCE. This study confirmed that UAE is an efficient and feasible technology for extracting polyphenols from H. erinaceus, which lays a theoretical foundation for the development and utilization of its polyphenols, and also provides novel insights into the development of natural functional ingredients and potential therapeutic agents for the intervention of type 2 diabetes. Additionally, the findings further validate edible fungi as a valuable reservoir of natural bioactive substances, with promising application prospects in the research and development of functional foods and pharmaceuticals targeting metabolic diseases. Full article

High concentrations of ionized ammonia (${\mathrm{NH}}_4^{+}$) have been increasingly reported in municipal drinking water systems, posing a severe public health risk as excessive ingestion can lead to life-threatening conditions. Despite its importance, there is a significant lack of sensing technologies designed for continuous-flow monitoring outside laboratory settings, particularly those providing a robust, low-cost methodology suitable for resource-limited environments. To address these challenges, in this work, we report the development of an impedance sensor featuring a 3D-printed housing (3D-IS) for monitoring aqueous ionized ammonia (${\mathrm{NH}}_4^{+}$). The sensing electrodes, composed of zinc oxide and graphite, allow for the detection of concentrations 10 times lower and 60 times higher than current environmental limits. Its innovative, optimized design, analogous to that of industrial pressure gauges, highlights its potential for use in continuous water flow conditions outside the laboratory, such as water treatment plants. The level of ${\mathrm{NH}}_4^{+}$ in water is monitored by changes in impedance magnitude, with optimal performance observed at a frequency of 100 kHz. At this frequency, the impedance magnitude decreased by nearly two orders of magnitude as the ${\mathrm{NH}}_4^{+}$ concentration increased from 0 to 1 μM. Under these optimized conditions, the sensor exhibited a sensitivity of 2 kΩ/log(μM) and a linearity exceeding 90%. Furthermore, we propose an equivalent circuit model that accurately describes the experimental data, explaining the transduction process. We also describe, from an electrical perspective, the phenomenon of adsorption on the sensor’s transducer surface, thereby ensuring the device’s selectivity. The sensor was evaluated using dilutions of a standard ammonium solution for IC in distilled water, as well as with real groundwater samples, obtaining ∼99.7% of correlation with ion chromatography and a limit of detection of 2 μM. Finally, our device can provide information relatively quickly, with the added advantage of stable response under continuous-flow and real conditions, making it an attractive option for integration into a field sensor node. Full article

Ion chromatography (IC) serves as a pivotal technique in trace ion analysis, and the separation performance of IC is largely determined by the properties of stationary phases. In contrast to silica-based matrices, polymer-based stationary phases have garnered significant interest owing to their outstanding pH stability and mechanical robustness. However, unmodified polymer matrices usually lack necessary ion exchange functions and selectivity; therefore, precise functional modification is the key to improving their chromatographic separation performance. This paper provides a systematic overview of recent advances in the synthesis and functional modification of polymer-based anion exchange chromatography stationary phases over the past few years. Firstly, the types and characteristics of polymer matrices commonly used for functional modification are summarized; secondly, the origin and improvement of common synthesis methods such as microporous membrane emulsification, droplet microfluidics, suspension polymerization, emulsion polymerization, soap-free emulsion polymerization, precipitation polymerization, dispersion polymerization, and seed swelling are introduced according to the molding methods of polymer matrices; furthermore, the principles, characteristics, and development status of mainstream functionalization strategies, including chemical derivatization, surface grafting, latex agglomeration, and hyperbranching, are emphasized. Finally, the existing challenges and prospective development trends in this field are discussed and outlooked, with the purpose of offering insights for the targeted design and practical application of high-performance polymer-based anion exchange chromatography stationary phases. Full article

This study investigated the site-specific ionic composition and wet deposition loads of rainwater collected from eight actively cultivated agricultural regions across South Korea, with the aim of quantifying spatial and seasonal variability and interpreting how regional agricultural characteristics and surrounding site conditions influence major ion concentrations and deposition patterns. Rainfall samples were obtained using automated samplers and analyzed via high-performance ion chromatography for major cations (Na⁺, $\mathrm{N}{\mathrm{H}}_4^{+}$, K⁺, Ca²⁺, Mg²⁺) and anions (Cl⁻, $\mathrm{N}{\mathrm{O}}_3^{-}$, $\mathrm{S}{\mathrm{O}}_4^{2-}$, $\mathrm{N}{\mathrm{O}}_2^{-}$). The results revealed significant seasonal fluctuations in ion loads, with $\mathrm{N}{\mathrm{H}}_4^{+}$ (peak 1.13 kg/ha) and K⁺ (peak 0.25 kg/ha) reaching their highest levels during summer due to increased fertilizer use and crop activity. Conversely, Cl⁻ peaked in winter (2.11 kg/ha in December), particularly in coastal regions, likely influenced by de-icing salts and sea-salt aerosols. Correlation analysis showed a strong positive association among $\mathrm{N}{\mathrm{H}}_4^{+}$, $\mathrm{N}{\mathrm{O}}_3^{-}$, and $\mathrm{S}{\mathrm{O}}_4^{2-}$ (r = 0.89 and r = 0.84, respectively), indicating shared atmospheric transformation pathways from agricultural emissions. Ternary diagram analysis further revealed regional distinctions: coastal regions such as Gimhae and Muan exhibited Na⁺ and Cl⁻ dominance, while inland areas like Danyang and Hongcheon showed higher proportions of Ca²⁺ and Mg²⁺, reflecting differences in aerosol sources, land use, and local meteorological conditions. These findings underscore the complex interactions between agricultural practices, atmospheric processes, and local geography in shaping rainwater chemistry. The study provides quantitative baseline data for evaluating non-point source pollution and developing region-specific nutrient and soil management strategies in agricultural ecosystems. Full article

This study aims to develop a chip-based five-electrode contactless conductivity detector for miniaturized ion chromatography (IC) systems. The detector comprises a detection chip (50 mm × 25 mm × 6 mm) and a detection circuit. The detection chip consists of a top layer, an insulating film, and a bottom layer wherein a planar five-electrode printed circuit board (PCB) is embedded. Among the five electrodes, one shielding electrode is designed to suppress the leakage current in the flow channel; consequently, the potential at the solution outlet is raised, further enhancing detection sensitivity. Furthermore, integrating the electrodes into a PCB module can reduce the difficulty of electrode fabrication and extend the lifespan of the electrodes. The detector was applied to a commercial IC system and successfully achieved the separation and detection of three anions (Cl⁻, NO₃⁻, SO₄²⁻). For standard solutions, the limit of detection (LOD) values of Cl⁻, NO₃⁻ and SO₄²⁻ are 0.47, 0.80, and 0.95 ppm, respectively. For mixed samples, the separation analysis was completed within 25 min, and the maximum detection error is no more than 2.2%. The five-electrode contactless detector developed shows great potential for application in miniaturized ion chromatography. Full article

In this study, an integrated analytical method coupling ultra-high-performance liquid chromatography–photodiode array detection–quadrupole time-of-flight mass spectrometry with total antioxidant capacity determination (UHPLC-PDA-Q-TOF/MS-TACD) was developed for the rapid screening and identification of antioxidants in complex natural extracts. The system enables simultaneous chromatographic separation, mass spectrometric characterization, and on-line activity assessment by combining 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and ferric ion reducing antioxidant power (FRAP) assays. When applied to Rosa rugosa samples from five different origins, the approach efficiently separated the extract and successfully localized antioxidants directly from the chromatographic profile. A total of 86 compounds were identified, including flavonoids, tannins, and phenolic acids. Among them, 60 exhibited free radical scavenging capacity and 59 showed reducing activity. Activity verification experiments showed that all seven compounds exhibited good antioxidant activity. The IC₅₀ values of gallic acid, ellagic acid, quercetin 3-O-rhamnoside, and rutin were 0.019, 0.025, 0.043, and 0.046 mM, respectively, which were significantly better than the positive control (vitamin C). This method provides methodological and technical support for the rapid discovery of antioxidant components in complex natural products. Full article

The traditional use of iced trash fish (IF) in Chinese mitten crab (Eriocheir sinensis) aquaculture raises sustainability concerns, but the shift to formulated feeds (FF—a commercial compound feed specifically designed to meet nutritional requirements by blending multiple ingredients and containing a balance of nutrients) is often hindered by fears of compromising its prized flavor. This study aimed to comprehensively evaluate whether a commercial formulated feed could effectively replace IF without diminishing flavor quality, hypothesizing that FF would alter the intestinal volatile profile, thereby influencing muscle flavor. Male crabs were fed either IF or FF for eight weeks. Muscle flavor was assessed using sensory evaluation, electronic nose (E-nose), and gas chromatography–ion mobility spectrometry (GC–IMS). Volatile compounds in intestinal chyme were also analyzed by GC–IMS to explore potential transfer mechanisms. The results indicated that crabs fed with FF showed higher sensory scores for sweetness. Additionally, the E-nose analysis revealed a clear separation trend between dietary groups and showed markedly higher sensor response values for aromatic compounds, biogenically derived compounds and Maillard reaction products, sulfur-containing organic compounds, aliphatic hydrocarbons, total volatile organic compounds, alcohols and organic solvents, and alkenes in the FF group compared to the IF group. Thirty-four volatiles were discovered in the muscle. Statistical analysis (independent samples t-test) showed that the FF group exhibited significantly elevated levels of 3-methylbutanal-M, propanal, (E)-2-pentenal, 2,3-pentanedione, and pentan-1-ol-M, whereas the IF group exhibited significantly elevated levels of 2-hexanone, dihydro-2(3H)-furanone, butyl acetate, ethyl 2-methylpropanoate, and phenol (p < 0.05). Fourty-eight volatiles were identified in the intestinal chyme. Propanal and ethyl 2-methylpropanoate were the dominant odor contributors based on correlation network analysis. Strong correlations were identified between the flavor profiles of intestinal chyme and muscle, suggesting a potential transfer or transformation of volatiles. This work provides a scientific basis for optimizing aquafeed formulations to ensure sustainable crab production without sacrificing end-flavor quality. Full article

Stingless bee cerumen is a mixture of wax and plant resins. Foragers of stingless bees are exposed to various chemical contaminants during their plant visits and collection activities. These contaminants have the potential to be transferred into the nest. This study aimed to elucidate the existence of chemical contaminants in Ecuadorian cerumen. To this end, the following aims were established: (i) to determine and quantify glyphosate (GLY), aminomethylphosphonic acid (AMPA), some other pesticides, metals and metalloids in cerumen and (ii) to establish possible risks associated with the presence of these chemical contaminants to the health of stingless bees and humans. The quantification of chemical contaminants was conducted using gas chromatography (GC), liquid chromatography (LC), and ion chromatography (IC) coupled to mass spectrometry (MS). Glyphosate (0.02–0.2 mg/kg) and AMPA (0.028 mg/kg) were detected in four of the pooled samples (n = 14) from the northern and southern highland regions. Other pesticide traces were not detected in any cerumen samples. Metals (Cd, Cr, Pb, Ni, Sn) and metalloids (As, Sb, Se) were found in all samples, including highlands and the lower Amazon. The potential risks of exposure to glyphosate and AMPA for stingless bees and humans appear to be minimal (except for the specific conditions given for Tetragonisca angustula) and safe, respectively. It seems that cerumen may serve as an effective biomonitoring matrix for assessing the environmental health of stingless bee nests. Establishing guidelines and regulations for the safe use and handling of products derived from the stingless bee consumption is therefore imperative. Full article

This study investigated the Yongning Fortress ruins in Taiyuan through a comprehensive analytical approach employing scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), laser particle size analysis, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and ion chromatography (IC). The research focused on elucidating the disturbance mechanisms and environmental impacts induced by the root systems of five representative herbaceous species on rammed earth structures. The results demonstrated distinct, species-specific disturbance patterns. Melica roots created three-dimensional network damage, Artemisia capillaris primarily caused deep root penetration, Fallopia aubertii exhibited coupled physical–chemical effects, Convolvulus arvensis induced shallow horizontal expansion damage, while Cirsium formed a heterogeneous structure characterized by dense taproots and loose lateral roots. Environmental conditions, particularly moisture content, significantly influenced disturbance intensity. All root activities led to common deterioration processes, including particle rounding, gradation degradation, and formation of organic–mineral composites. Notably, vegetation markedly altered soluble salt distribution patterns, with Cirsium increasing total salt content to 3.7 times that of undisturbed rammed earth (0.48%), while sulfate ion concentration (1.16 × 10⁻³) approached hazardous thresholds. The study established a theoretical framework linking plant traits, disturbance mechanisms, and environmental response, and proposed risk-based zoning strategies for preservation. These outcomes provide significant theoretical foundations and practical guidance for the scientific conservation of rammed earth heritage sites. Full article

Dendrobium denneanum Kerr, Dendrobium denneanum Kerr, an orchid in the food-medicine homology catalog, is traditionally used for stomach-nourishing, yin-tonifying, and immunity-enhancing. While its preventive effect on acute gastric ulcers is confirmed, variations among genuine producing areas remain underexplored. This study comparatively analyzed components of D. denneanum from 22 habitats and their polysaccharides’ (DDP) anti-inflammatory/antioxidant activities. Results showed habitat-dependent active components: total sugar (20–51.49%), crude polysaccharide yield (0.29–1.76%), and total phenol (~3%). In vitro, all extracts exhibited dose-dependent scavenging of DPPH (IC₅₀: 0.99–2.11 mg/mL), ABTS (0.61–1.62 mg/mL), and hydroxyl radicals (1.02–2.18 mg/mL), with Habitats 5 and 7 showing the strongest activity. GPC, ion chromatography, and FT-IR revealed DDP had a 5–11 kDa molecular weight, dominated by glucose (49.67–84.73%), plus mannose (8.29–12.25%) and galactose (0.96–16.41%), with shared hydroxyl (3400 cm⁻¹) and β-glycosidic bond (890 cm⁻¹) features. In ethanol-induced gastric ulcer rats, DDP exerted dose-dependent protection: low doses (100 mg/kg/d) reduced ulcer index, increased SOD/GSH-Px (1.5–1.8-fold), decreased MDA (30–35%), and elevated PGE₂; high doses (400 mg/kg/d) further inhibited serum TNF-α/IL-6 (25–40%) and improved histopathology. Conclusion: Despite habitat-dependent component variations, DDP maintains consistent structures. This study first confirms DDP protects gastric mucosa via antioxidant-anti-inflammatory synergism, supporting its development as a natural gastroprotectant. Future work may focus on standardized cultivation and clinical translation. Full article