Search Results (409)

Microplastics (MPs) and nanoplastics (NPs) accumulate in human hepatic and gastrointestinal (GI) tissues. However, differences in sampling strategies, tissue preparation, analytical techniques, and quality assurance procedures have resulted in substantial methodological heterogeneity, limiting the comparability and reproducibility of published findings. Therefore, this review aims to critically evaluate current analytical methodologies for the detection and characterization of MPs and NPs in hepatic and GI tissues, highlight methodological strengths, limitations, and emerging technologies, and identify priorities for methodological standardization. Studies demonstrate that no single analytical technique can simultaneously provide comprehensive information on particle size, morphology, polymer composition, spatial localization, and concentration. While Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), and emerging multimodal imaging techniques each offer distinct advantages, reflecting their different underlying detection principles, methodological variability remains a major barrier to cross-study comparison. Human tissue studies are further constrained by limited sample availability, contamination risks, and inconsistent quality assurance procedures. Future progress will depend on harmonized, organ-specific analytical workflows integrating optimized tissue digestion, rigorous contamination control, complementary spectroscopic approaches, and standardized reporting metrics. Establishing unified methodological guidelines is essential to improve reproducibility, facilitate quantitative evidence synthesis, and advance both environmental exposure assessment and clinical research on MPs and NPs in hepatic and gastrointestinal tissues. Full article

Pyroligneous liquor (PL) is a by-product of charcoal production with potential applications in agriculture, forestry, and industry. This study evaluated the influence of carbonization temperature on the yield, chemical composition, and physicochemical properties of PL obtained from Eucalyptus spp. in a sustainable kiln-furnace system. PL fractions were collected at four temperature intervals: T1 (60–170 °C), T2 (171–270 °C), T3 (271–350 °C), and T4 (351–400 °C). The recovery of condensable gases did not affect the quality of the charcoal and minimized pollutant emissions. Gas chromatography–mass spectrometry (GC-MS) identified 78 organic compounds, mainly carboxylic acids, phenolic compounds, alcohols, carbohydrates, and aromatics. The highest PL yield was obtained in T3 (271–350 °C), accounting for 27% of the recovered liquor and showing high phenolic content, including syringol and catechol. In contrast, T1 (60–170 °C) showed the lowest yield and was dominated by carboxylic acids, particularly acetic acid. Carbonization temperature affected both PL composition and physicochemical properties, resulting in higher electrical conductivity and vegetable tar content at higher temperatures. Hierarchical cluster analysis revealed distinct compound groups according to their concentration patterns across the evaluated temperature intervals. These results reinforce the notion that the evolution of pyrolysis vapors is not a continuous or homogeneous process, but rather occurs through discrete and chemically distinct stages driven by the sequential decomposition of hemicellulose, cellulose, and lignin—a behavior that directly justifies the temperature-based fractionation approach adopted. It was found that temperature-controlled fractionation effectively yields pyrolysis liquid (PL) fractions with distinct chemical profiles, facilitating the selective recovery of value-added compounds for forest biomass biorefineries and specific end-use applications, in addition to offering environmental benefits. Full article

The resource utilization of eutrophic cyanobacterial biomass provides a sustainable route for developing biochar-based catalytic materials for dye wastewater treatment. Herein, eutrophic cyanobacteria from Dianchi Lake, Kunming, were used as raw materials to prepare functional catalytic materials via pyrolysis-modification. A trimetallic photocatalyst, CuFeZnXBC₄₀₀ (XBC = cyanobacterial biochar), was fabricated for methylene blue (MB) degradation without hydrogen peroxide or other external oxidants. The samples were characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), liquid chromatography–mass spectrometry (LC–MS), and three-dimensional fluorescence spectroscopy. At an initial MB concentration of 100 mg/L and pH 11, under UV irradiation, CuFeZnXBC₄₀₀ achieved nearly 99% MB removal within 60 min and retained over 90% activity after eight cycles. Transient photocurrent measurements and quenching experiments indicated that photogenerated holes (h⁺) were the dominant oxidative species, while superoxide radicals (·O₂⁻) contributed to the reaction and hydroxyl radicals (·OH) played a limited role. LC–MS analysis supported the chemical transformation of MB, and three possible degradation pathways were proposed. The development of CuFeZnXBC400 provides a new biochar-based material and a potential strategy for cyanobacterial biomass utilization and organic dye wastewater treatment. Full article

Nanoplastics (NPs) in drinking water should be interpreted as the downstream analytical endpoint of a broader continuum of aquatic plastic pollution rather than as an isolated problem. Their detection remains analytically immature because environmentally relevant concentrations are low, particle chemistries are heterogeneous, natural colloids and treatment residuals interfere with measurement, and no single method can simultaneously resolve size, morphology, polymer identity, and mass concentration. Unlike occurrence-centered reviews, this PRISMA-guided review treats drinking-water nanoplastics as a metrological and molecular-identification problem in which preprocessing, particle-level confirmation, polymer-specific quantification, and uncertainty reporting must be integrated. A formal search was closed on 11 April 2026 using prespecified query families across publicly accessible scholarly records and backward citation chaining; 33 unique records were screened, 25 full texts were assessed, and 22 studies were included in the qualitative synthesis. Current evidence indicates that conventional FTIR and routine Raman workflows are inadequate for true nanoscale analysis, whereas advanced Raman-based approaches, AFM-IR, optical photothermal infrared spectroscopy, surface-enhanced Raman spectroscopy, and pyrolysis-gas chromatography-mass spectrometry offer complementary strengths but still have major limitations in throughput, particle-level information, or quantification. The main conclusion is that current uncertainty reflects unresolved analytical chemistry and metrological constraints as much as environmental variability. Regulatory progress will depend on orthogonal workflows, contamination-controlled preprocessing, validated reference materials, LOD/LOQ reporting, and interlaboratory harmonization. Full article

Detection of nanoplastics in drinking-water systems is only the first analytical step toward exposure interpretation; the next challenge is source attribution. This review examines molecular fingerprinting and transformation pathways that can link nanoscale polymer signals to source waters, drinking-water treatment, distribution infrastructure, packaging materials, laboratory background, or aging processes across the potable-water chain. Nanoplastics are treated here as operationally defined particles below 1 µm, including intentionally manufactured primary nanoplastics and secondary nanoplastics generated by fragmentation, abrasion, weathering, treatment, storage, or packaging stress. The synthesis evaluates how polymer identity, particle morphology, surface oxidation, additive and oligomer profiles, thermal degradation markers, matrix context, and quality assurance/quality control (QA/QC) can be combined into defensible source assignments. Analytical platforms considered include surface-enhanced Raman spectroscopy (SERS), atomic force microscopy–infrared spectroscopy (AFM-IR), optical photothermal infrared spectroscopy (O-PTIR), stimulated Raman scattering microscopy (SRS), pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS), asymmetric flow field-flow fractionation coupled to Py-GC/MS (AF4-Py-GC/MS), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and chemometric workflows. The central conclusion is that source attribution cannot be inferred from polymer identity alone; robust interpretation requires convergent evidence from particle-level chemistry, polymer-specific mass, additive or marker-ion signatures, aging state, blanks, recovery, and contextual sampling design. Full article

Rice cultivation generates a substantial amount of rice husks (RH) as agricultural waste from rice milling, which is not effectively utilized for environmentally friendly products. This study investigates the product yields and chemical characteristics of RH pyrolysis conducted at temperatures between 400 and 600 °C, at 50 °C intervals, with heating rates of 5, 10, and 20 °C/min. The highest liquid product yield (30.57%) was achieved at 600 °C under a heating rate of 20 °C/min. Gas chromatography–mass spectrometry (GC–MS) characterization revealed that the liquid product consisted predominantly of complex mixtures, with C6 compounds dominating the carbon number distribution, followed by C8 and C5 compounds. During the pyrolysis process, CO₂ and CO were the main components of the non-condensable gases, whereas total hydrocarbons (THC) were generated at pyrolysis temperatures of 500 °C and above. The carbon content of biochar increased as the pyrolysis temperature increased, while the oxygen and hydrogen contents decreased. These findings elucidate the influence of temperature and heating rate on the chemical properties of pyrolysis products derived from RH. In addition, the kinetic analysis of RH pyrolysis showed that the estimated activation energy varies depending on the applied method. Therefore, the combined use of multiple methods is considered desirable for providing a more reliable kinetic interpretation of RH pyrolysis. Full article

Advanced oxidation processes based on peracetic acid (PAA) have emerged as a sustainable strategy for water treatment; however, developing efficient, stable, and environmentally friendly catalysts remains challenging. In this study, a functional cobalt-based catalyst (CPBC_x) was fabricated by immobilizing cobalt ions onto phytic-acid-modified biochar to active PAA for the degradation of sulfamethoxazole (SMX). The effect of pyrolysis temperature on the catalytic performance was investigated, with CPBC₈ showing the highest SMX degradation efficiency, under the conditions of a CPBC8 dosage of 200 mg/L, a PAA concentration of 0.2 mM, and an initial SMX concentration of 5 mg/L, and a 99.0% removal of SMX was achieved within 10 min. Moreover, the removal efficiency remained above 90% after five consecutive cycles. Mechanistic analysis revealed that biochar, acting as an efficient electron shuttle, enhanced electron transfer and accelerated the Co²⁺/Co³⁺ redox cycle, thereby shifting the SMX degradation pathway from a radical-dominated route to a non-radical one dominated by singlet oxygen (¹O₂). Density functional theory (DFT) calculations identified the vulnerable attack site (N11) on the SMX molecule. Transformation products and degradation pathways were elucidated using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC-TOF-MS), and the identified intermediates exhibited low ecotoxicity. Furthermore, the CPBC₈ composite demonstrated sustained degradation rates, good stability, and environmental compatibility for practical application. This study provides a sustainable and efficient solution for applying biochar-based PAA advanced oxidation processes in water treatment. Full article

Polystyrene nanoplastic (PS-NP) contamination poses an emerging threat to aquaculture species, yet time-resolved assessments integrating host physiology, gut microbial ecology, and tissue bioaccumulation remain limited. Here, we evaluated the temporal effects of 100 mg/L PS-NPs (100 nm) on Cherax quadricarinatus (Von Martens, 1868) over a 3-week exposure period. Crayfish were assigned to a control group (Group A) and three treatment groups exposed for 1 (Group B), 2 (Group C), or 3 (Group D) weeks. No mortality occurred. Hepatopancreatic antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) displayed a hormetic response (upregulation at weeks 1–2 followed by depletion at week 3), indicating oxidative stress overload. Alkaline phosphatase activity declined progressively, reflecting cumulative immunosuppression. Histological examination revealed time-dependent structural damage in the hepatopancreas: hepatic tubule enlargement, increased vacuolation, B cell hypertrophy, and cellular disorganization/lysis after three weeks. 16S rRNA sequencing revealed that PS-NPs induced time-dependent gut dysbiosis, characterized by depletion of beneficial taxa and enrichment of opportunistic pathogens. Alpha-diversity metrics (ACE, Chao1, Shannon) were significantly reduced in Group D compared to controls, confirming loss of microbial evenness and richness. Pyrolysis gas chromatography–mass spectrometry quantification demonstrated marked PS-NP bioaccumulation in the hepatopancreas, with concentrations rising from 6.94 μg/g in controls to 65.38 μg/g in Group D, a 9.4-fold increase. Collectively, prolonged PS-NP exposure is associated with oxidative stress, immune dysfunction, progressive gut dysbiosis, and substantial hepatopancreatic nanoplastic burden in C. quadricarinatus. These findings carry implications for ecological risk assessment and highlight the need for further investigation into food safety risks associated with human consumption of crayfish from PS-NP-contaminated environments. Full article

Microplastics (MPs) are increasingly detected in dairy products, raising food-safety concerns. Their behavior in complex food matrices and interactions with probiotic microorganisms remain poorly understood. This exploratory study evaluated storage-dependent changes in operationally defined, digestion-resistant recoverable residues in yogurt containing Bifidobacterium longum subsp. infantis (ATCC 15697). Yogurt samples were prepared with polypropylene (PP), polyethylene (PE), and polystyrene (PS), individually and in combination, and analyzed over 21 days of refrigerated storage. Gravimetric values served as relative, operational indicators of recoverable residues—not validated absolute polymer masses—while polymer identity was qualitatively confirmed by pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). B. longum subsp. infantis remained viable throughout storage (6.3–8.2 log₁₀ CFU/g). All MP-containing groups showed consistent storage-associated decreases in recoverable residue fractions, greatest in PP, followed by PE and PS; probiotic-free controls remained stable. Polymer-specific Py-GC/MS signals were detectable at all time points. Because polymer identity was retained and the workflow was not validated for absolute recovery, findings are interpreted as storage-associated changes in extractability, filterability, and/or residue recovery—not as polymer degradation, mineralization, or biological removal. These in vitro observations are limited to the yogurt matrix and do not support extrapolation to livestock exposure, human dietary risk, or farm-to-fork transfer. Within these limits, the findings provide a preliminary, hypothesis-generating perspective on probiotic–microplastic interactions in fermented dairy products. Full article

The sustainability, crop production, and food safety of agriculture are increasingly challenged by microplastic pollution, as agricultural soils are the largest reservoirs and may serve as points of contact for plastic particles in the food chain. This review provides a comprehensive overview of plant materials, fate and uptake pathways, detection techniques, and the possible risks of microplastics in agriculture. Agroecosystems are also a source of microplastics, such as plastic mulch films, sewage sludge, compost and manure additives, wastewater irrigation, polymer-coated fertilizers, greenhouse materials, atmospheric deposition, and decomposition of discarded agricultural plastics. Their distribution and mobility in soil are controlled by polymer composition, particle size, morphology, density, surface ageing, soil texture, organic matter content, tillage practices, runoff, leaching, and soil biota. Recent data show that microplastics, especially smaller microplastics and nanoplastics, can attach to root surfaces, penetrate plants via cracks in roots, areas of lateral root development, and apoplastic pathways, and eventually move to tissues aboveground. Plant tissue detection is often accomplished by digestion of the sample, density separation, visual and fluorescence microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, pyrolysis–gas chromatography mass spectrometry, and electron microscopy, but standardization of these methods remains a significant challenge. Microplastics can disrupt seed germination, root structure, nutrient absorption, photosynthesis, oxidative homeostasis, biomass buildup, yield development, and quality. Further, their capacity to transport additives, plasticizers, heavy metals, and persistent organic pollutants raises concerns about the transfer of contaminants to edible plant parts and their potential transfer to human diets. Further studies are needed focusing on field-realistic exposure conditions, long-term crop–soil interactions, nanoplastics behaviour, standardised analysis procedures, uptake and translocation pathways, edible crop risk assessments, and sustainable mitigation approaches to reduce microplastics in agroecosystems. Full article

Chinese lacquerware is a multi-layered natural polymer composite whose characterization is complicated by burial degradation, organic–inorganic mixing, and the overlap of signals from lacquer, drying oils, proteins, polysaccharides, waxes, and pigments. This review evaluates analytical strategies for Chinese lacquerware by distinguishing three complementary levels of evidence: morphological and elemental observation, chemically specific molecular fingerprinting, and biomolecular source recognition. Microscopy, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS) are useful for identifying stratigraphy, pigments, fillers, and functional groups, but they are often insufficient for assigning degraded organic matrices and trace additives independently. Pyrolysis–gas chromatography/mass spectrometry provides more specific molecular evidence through diagnostic marker classes, including alkyl catechols, alkyl phenols, nitrogen-containing pyrolysis products, anhydrosugars, long-chain aliphatics, aldehydes, and ketones. Immunological assays based on lacquer glycoproteins further complement chemical analysis by supporting biological source differentiation, although their reliability depends on protein preservation, extraction efficiency, and antibody specificity. Representative case studies, including a seventeenth-century Swedish lacquered pipe, the Nanyue Kingdom lacquered ear cup, and a Tang Dynasty lacquered leather artifact, show that robust interpretation requires cross-validation among stratigraphic, elemental, spectroscopic, chromatographic, immunological, and archaeological evidence. The review concludes that integrated analytical workflows can improve material identification, clarify manufacturing sequences, assess degradation uncertainty, and provide more reliable evidence for conservation decision-making and the reconstruction of historical lacquer craftsmanship. Full article

Lithium-ion batteries have become crucial energy carriers in multiple core fields owing to their excellent comprehensive performance. Nevertheless, as battery energy and power densities continue to rise and operating conditions grow increasingly complex, thermal safety issues have become increasingly prominent. Immersion liquid cooling technology has attracted widespread attention in academic and engineering fields for its outstanding heat transfer and temperature uniformity performance. As a core component of this technology, the selection of liquid coolants is of vital importance. Various coolants investigated in existing studies generally suffer from limitations to varying degrees. Against this backdrop, intrinsically safe fluorocarbon C₇H₄F₁₂O (3F-135) serves as an ideal liquid cooling medium for lithium-ion batteries, thanks to its high thermal stability, superior electrical insulation and environmental friendliness (zero ODP, extremely low GWP). However, its decomposition mechanism and reaction pathways under extreme thermal runaway conditions of batteries remain unclear. In this study, a tube furnace was adopted to simulate high-temperature environments induced by thermal runaway, and gas chromatography–mass spectrometry (GC-MS) was employed to analyze decomposition products and decomposition ratios of 3F-135. Subsequently, density functional theory (DFT) calculations were utilized to construct the pyrolysis reaction network of 3F-135. Ultimately, the dominant pyrolysis pathways in different temperature ranges were clarified, providing theoretical support for the application and selection of intrinsically safe liquid coolants. Full article

Chemical recycling of mixed plastic waste can recover hydrocarbon products, but additive-derived non-intentionally added substances (NIASs) and other volatile or extractable residues may affect product quality and safety. In this study, six polyolefin-rich waste streams (P1–P6) were analyzed by analytical pyrolysis coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (Py–GC×GC–TOF–MS), while three additional consumer-grade plastics (P7–P9) were examined by headspace/solvent-extraction GC–MS and aqueous migration testing to profile volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), and water migrants. Under rapid pyrolysis at 650 °C, the condensable products were dominated by C5–C30 aliphatic hydrocarbons. Polyethylene (PE)-rich feeds produced mainly n-paraffins and α-olefins, whereas polypropylene (PP)-rich feeds produced more branched olefins and modest mono-aromatics. Oxygenated compounds were negligible in non-oxidized feeds, but persisted at low levels in weathered high-density polyethylene (HDPE), consistent with pre-existing oxidation. Antioxidant-derived NIASs, including 2,4-di-tert-butylphenol and an Irganox 1010-related spiro-dione, were detected at trace to low area-fraction levels. VOC/SVOC and migration analyses revealed mainly low-intensity hydrocarbons, esters, antioxidant-related degradation products, caprolactam, and selected plasticizer-related compounds. These results show that relatively clean polyolefin streams can yield hydrocarbon-rich pyrolysates, but oxidized PE and additive-derived NIASs remain important quality-control targets. The GC-based methods used here characterize the volatile, condensable, and readily extractable fraction and do not represent the total contaminant load of the source waste. Full article

The chemical complexity of post-consumer plastics represents a major challenge for achieving high-quality recycling. In this study, post-consumer high-density polyethylene (HDPE) packaging materials were analysed using pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) to investigate relationships between compound origin, degradation pathways, and contaminant profiles. More than one hundred organic compounds were detected and classified into four main groups: product-related inputs, polymer formulation chemistry, polymer degradation processes, and external contamination. Polymer degradation products, particularly radical rearrangement and cyclisation compounds, represented the most diverse group, indicating advanced transformation of the polymer matrix associated with repeated processing. Additive-derived compounds, including phenolic structures and epoxide-containing species, contributed to the pool of non-intentionally added substances (NIAS), while persistent compounds, such as fluoropolymer-derived residues, were detected across most samples. In contrast, product-related inputs showed high variability and a generally lower contribution. Multivariate analysis revealed that samples were not clustered according to product category but rather distributed along gradients defined by degradation, additive transformation, and contamination processes. These findings demonstrate that the chemical composition of recycled HDPE is determined or influenced by multiple independent factors. The results support the need for chemistry-informed recycling strategies. Full article

Nowadays, bioplastics are increasingly being used as an alternative to single-use fossil-based plastics. However, a major challenge associated with bioplastics is the need for higher amounts of plastic additives to achieve material properties comparable to those of conventional plastics, which raises concerns regarding their potential ecological impact. In this study, we evaluated the capacity of mixed liquor sludge from a wastewater treatment plant (WWTP) to eliminate bioplastics and their associated plastic additives compared to fossil-based materials. To this end, we exposed three items under controlled laboratory conditions: pure polylactic acid (PLA) pellets, a PLA garbage bag and a conventional fossil-based polyethylene (PE) bag. The study of plastic degradation was carried out by pyrolysis coupled with gas chromatography high-resolution mass spectrometry (Pyr-GC-HRMS). The results show a higher degree of degradation of biobased bags (96.8 ± 4.0%) and PLA pellets (91.3 ± 9.0%), whereas fossil-based bags of PE exhibited negligible degradation (18.3 ± 25.8%). Furthermore, leaching compounds generated during the treatment process were monitored using a suspect screening strategy by means of liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). The main results showed that the concentration of several tentatively identified compounds increased after treatment because of the leaching process or because they were degradation products of other previously leached additives. The evaluation of the associated toxicity of these compounds using predicted no-effect concentrations (PNECs) disclosed that these compounds may pose a risk to organisms in receiving waters. Full article