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This work focuses on the changes in the chemical composition of wood caused by impregnation with fire retardants such as guanidine carbonate (GC), urea (U), diammonium phosphate (DAP) and their mixtures. The treated wood was tested using the oxygen index (LOI), Py–GC/MS analysis and FTIR Spectroscopy. The wood was vacuum treated at a pressure of 0.8 MPa for 20 min and then subjected to thermal degradation using the LOI. This way, degraded and nondegraded layers were obtained and ground (0.2 mm). All treatment variants achieved the class of non-flammable materials based on LOI tests; the exception was the 5% urea solution, defined as a flame-retardant material. Using the analytical methods, it was found that cellulose and hemicelluloses undergo the fastest thermal degradation. This study found that the variant protected with a 5% mixture of GC and DAP before and after the degradation process had the best fire-retardant properties regarding cellulose content in the wood. The highest content of anhydrosugars characterised the same variants, the amount of which indicates a slowdown in the degradation process and, consequently, a reduction in the release of levoglucosan during combustion, suggesting potential applications in fire safety. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reclamation of coastal marshes to croplands lost massive reserves of soil organic matter (SOM). However, it is uncertain how reclamation shifts chemical composition of SOM and its size fractions. Here, we investigated this issue at two coastal marshes (Qilihai, degradation with seasonal waterlog; Beidagang, annual long‐term waterlog) along with adjacent long‐term reclaimed croplands on the coast of the Bohai Bay, China. Three SOM fractions: coarse particulate (cPOM, >250 μm), fine particulate (fPOM, 53–250 μm), and mineral‐associated organic matter (<53 μm) were analyzed by pyrolysis‐gas chromatography–mass spectrometry. Compared with the Qilihai marsh, the Beidagang marsh had higher SOM contents and lower proportions of microbial‐derived N‐containing compounds, which was attributed to the waterlogging‐induced weaker decomposition. Reclamation decreased the SOM contents (−53.6% to −63.3%) and proportions of lignin in cPOM (−44% to −52%) at both sites. However, reclamation‐induced shifts of molecular composition of SOM between the two sites diverged. At the Qilihai site, reclamation decreased the relative abundances of N‐containing compounds (−28%) but increased the proportions of lipids (+17%) and phenolics (+40.7%) in mineral‐associated organic matter. At the Beidagang site, reclamation decreased the proportions of monocyclic aromatics (−60.3% to −70.2%), but increased the relative abundances of N‐containing compounds (+175% to +407%) in all fractions. By contrast, the molecular composition of SOM at the two croplands had covergent pattern. In conclusion, despite of marsh locations with different waterlogging conditions, long‐term reclamation of wetlands to croplands generated convergent patterns in storage and molecular composition of SOM, which was attributed to the similar cropland cultivation. [ABSTRACT FROM AUTHOR]

Organic carbon (OC) association with soil minerals stabilizes OC on timescales reflecting the strength of mineral-C interactions. We applied ramped thermal oxidation to subsoil B horizons with different mineral-C associations to separate OC according to increasing temperature of oxidation, i.e. thermal activation energy. Generally, OC released at lower temperatures was richer in bioavailable forms like polysaccharides, while OC released at higher temperatures was more aromatic. Organic carbon associated with pedogenic oxides was released at lower temperatures and had a narrow range of 14C content. By contrast, N-rich compounds were released at higher temperatures from samples with 2 : 1 clays and short-range ordered (SRO) amorphous minerals. Temperatures of release overlapped for SRO minerals and crystalline oxides, although the mean age of OC released was older for the SRO. In soils with more mixed mineralogy, the added presence of older OC released at temperatures greater than 450°C from clays resulted in a broader distribution of OC ages within the sample, especially for soils rich in 2 : 1 layer expandable clays such as smectite. While pedogenic setting affects mineral stability and absolute OC age, mineralogy controls the structure of OC age distribution within a sample, which may provide insight into model structures and OC dynamics under changing conditions. This article is part of the Theo Murphy meeting issue Radiocarbon in the Anthropocene.

This study examines the intricate thermal decomposition of sweet sorghum bagasse, an agricultural residue with significant potential as a renewable energy and biofuel feedstock. Both slow and flash pyrolysis has been conducted over a temperature range of 300–450°C and flash pyrolysis experiments were performed through analytical pyrolysis via Py-GC/MS to comprehensively assess the pyrolysis behaviour and elucidate the biomass degradation pathways. In the slow pyrolysis experiments, sweet sorghum bagasse underwent controlled thermal decomposition at different temperatures (300–450°C), allowing for the investigation of the influence of temperature on product yields and compositions. The evolved volatile compounds and biochar products were analyzed to determine the impact of temperature on biomass degradation. The results revealed that 400°C is the optimum pyrolysis temperature for maximizing valuable bio-oil production with approximately 42 wt.% yields with an overall conversion of 73%. Various characterization techniques were employed to analyze the slow pyrolysis products, including GC-MS, TGA, FTIR, SEM, and XRD. Flash pyrolysis was employed to provide a detailed understanding of the rapid biomass breakdown under extreme heating conditions with a heating rate of 20°C/ms to complement the slow pyrolysis findings. This technique elucidated the primary mechanisms responsible for the degradation of sweet sorghum bagasse, shedding light on the fragmentation patterns and the formation of vital intermediate compounds during flash pyrolysis. These insights into the transient phenomena occurring during pyrolysis provide valuable information for developing efficient and sustainable biomass conversion processes. The pyrolysis behaviour of sweet sorghum bagasse (SSB) is comprehensively assessed using TGA, slow pyrolysis via lab scale glass tubular reactor and flash pyrolysis via analytical tool Py-GC/MS from 300–450°C. The study reveals the potential use of SSB as a renewable energy and biofuel feedstock. [ABSTRACT FROM AUTHOR]

Abstract Folk contract documents (FCD) are valuable materials for studying social history, and the paper they use reflects the social realities of different eras and social classes. Research and scientific analysis of numerous FCD samples after the fourteenth century are rare. We conducted a study on 96 Tianshui folk contract documents (TFCD, 107 paper samples) from the Tianshui area of Gansu Province, Northwest China, taking into account both the textual content and the materiality of paper carriers, and interpreted the results from multiple lines of evidence and discussion. Physical performance analysis revealed that the paper used by the northern folk exhibits a lower apparent density, which is not conducive to the long-term preservation of paper. The preservation status investigation, curtain pattern analysis, and fiber analysis show that the paper used in the TFCD differs from traditional cultural paper regarding disease types, production precision, and fiber materials, providing a basis for its protection and restoration. The analysis of chemical components indicated that the aging and yellowing of paper can be correlated with the content of sulfur and carbonyl groups. The feasibility of using pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) analysis to quickly identify papermaking fibers in a large number of paper samples was proposed. By utilizing various techniques to inspect the paper of documents, this study helps to enhance the academic understanding of FCD materials. In addition, it expands the knowledge base of Northwest handmade paper.

Abstract Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics.

Taking Gonghe oil shale as raw material, the rapid pyrolysis experiment was carried out using the Py-GC/MS device under different atmospheres. The effects of different pyrolysis atmospheres on the rapid pyrolysis products of Gonghe oil shale were studied. The results show that the H2 atmosphere can not only increase the content of saturated hydrocarbons and reduce the content of unsaturated hydrocarbons but also reduce the content of oxygen-containing heterocyclic compounds. This may be because more H free radicals under the H2 atmosphere are produced to react with the free radical fragments formed by kerogen decomposition. The coupling between H free radicals and free radical fragments can prevent the polymerization among macromolecular free radicals and inhibit the generation of heavy byproducts, which can promote the kerogen pyrolysis and increase the release of volatile matter. In addition, the pyrolysis atmosphere is conducive to the deoxygenation of oxygen-containing heterocyclic compounds to a certain extent. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Archival writing material is an important carrier to record and reflect archival content, and its material and durability are closely related to the life of archives. The "Shuyede" press in Shandong Province, which originated in the reign of Kangxi (1662 AD–1722 AD) in the Qing dynasty, printed many important archives and ancient books of the Qing dynasty (1644 AD–1911 AD). In order to explore the material composition of woodblock printing ink from the Shuyede press, modern analytical and detection techniques such as scanning electron microscopy–energy-dispersive spectrometry (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), gas chromatography–mass spectrometry (GC/MS), and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) were applied for the analysis and identification of the ink on woodblock plates from the Shuyede press. The results showed that two kinds of printing ink—pine soot ink and oil soot ink—used were in these woodblocks from the Shuyede press in the Qing dynasty in the collection of Shandong Museum, and the binding material in the ink was animal glue, indicating that both pine and oil soot inks were used as printing ink in the Qing dynasty. [ABSTRACT FROM AUTHOR]

Pyrolytic synergistic interactions, in which the production of pyrolyzates is enhanced or inhibited, commonly occur during the co-pyrolysis of different polymeric materials, such as plastics and biomass. Although these interactions can increase the yield of desired pyrolysis products under controlled degradation conditions, the desired compounds must be separated from complex pyrolyzates and further purified. To balance these dual effects, this study was aimed at examining pyrolytic synergistic interactions during slow heating co-pyrolysis of biodegradable plastics including polylactic acid (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexaoate) (PHBH) and petroleum-based plastics including high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS). Comprehensive investigations based on thermogravimetric analysis, pyrolysis–gas chromatography/mass spectrometry, and evolved gas analysis-mass spectrometry revealed that PLA and PHBH decompose at lower temperatures (273–378 °C) than HDPE, PP, and PS (386–499 °C), with each polymer undergoing independent decomposition without any pyrolytic interactions. Thus, the independent pyrolysis of biodegradable plastics, such as PLA and PHBH, with common plastics, such as HDPE, PP, and PS, can theoretically be realized through temperature control, enabling the selective recovery of their pyrolyzates in different temperature ranges. Thus, pyrolytic approaches can facilitate the treatment of mixed biodegradable and common plastics. [ABSTRACT FROM AUTHOR]

Cangjie Temple was built to commemorate Cangjie, the legendary inventor of Chinese characters. It stands as one of the few remaining temples in China dedicated to the invention and creation of writing. In this study, the material properties of wooden paintings from the Cangjie temple were characterized using Polarized Light Microscopy (PLM), Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Micro-confocal Raman Spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC/MS). It was confirmed that the pigments of the paintings included cinnabar, lapis lazuli, lead white, Paris green, and carbon black. The proteinaceous glue was used as an adhesive in the pigment samples, with tung oil likely being utilized as a primer for the wooden structures before painting. This study not only provides valuable data support for the conservation and restoration of the architectural features of Cangjie Temple but also provides useful reference for the maintenance and inheritance of similar ancient buildings. [ABSTRACT FROM AUTHOR]

Purpose: The chemistry of soil organic matter (SOM) is fundamental for sustainable and climate-smart agroecosystems. However, the differences in SOM chemistry between the upland and paddy soils developing under the same climatic and edaphic conditions are unclear. Materials and methods: Py-GC/MS was applied to characterize the biochemical features of SOM in three physical size fractions: coarse particulate (> 0.25 mm, cPOM), fine particulate (0.053–0.25 mm, fPOM), and mineral-associated OM (< 0.053 mm, MAOM) of upland and paddy fields under long-term (> 30 years) mineral and manure fertilizations. Results and discussion: Paddy fields had higher contents of soil organic carbon (SOC) and total nitrogen (TN) mainly accumulated in MAOM fraction than uplands. These two soils had different molecular compositions of SOM: N-containing compounds including amino-N and heterocyclic-N compounds enriched in the uplands, whereas paddy had higher proportions of lipids and phenolics. The SOM composition was also dependent on particle size, especially in the uplands, where POM fractions had high contents of lignin and MAOM accumulated N-containing components. In contrast, POM in paddy accumulated polysaccharides, whereas MAOM was enriched with lipids. Particle size controlled the C oxidation state (Cox), and paddy soils had higher Cox than that of uplands, mainly in the MAOM fraction. Conclusions: The molecular composition SOM was primarily regulated by land-use type, following by fraction size and fertilization regime, while the Cox was controlled by fraction size. The Cox needs more attention to understand the direction of formation of SOM fractions. [ABSTRACT FROM AUTHOR]

In this work, electrospun polylactide fibers with new photostabilizing additives, 4-methyl-2,6-diisobornylphenol (DIBP) and N-isocamphylaniline (NICA), have been tested under the influence of UV-C radiation (254 nm). The changes in the polymers' chemical structure under UV-C radiation were revealed through the increase in absorption in the 3600–3100 cm−1 region in regard to the FTIR spectra. In the samples that were irradiated for 1 h, the stabilizing effect of the photoprotectors became most noticeable as the difference in the content of the hydroxyl groups in stabilized and the pure PLA reached a maximum. The TG–DSC method revealed that the most sensitive indicator of the irradiation effect was the glass transition temperature (Tg), which persisted after 2 h of irradiation when using photostabilizers and their combinations. The PLA/DIBP(1) and PLA/NICA(1) samples showed the best results in protecting PLA from UV-C radiation based on the Tg values; although, the mixture of DIBP and NICA was not as effective. The chemical structure of the photostabilized PLA samples was studied using NMR, GPC, and Py–GC/MS analysis. The electrospun polylactide fibers were mechanically tested and the effects of the electrospun samples on cell viability were studied. [ABSTRACT FROM AUTHOR]

In order to develop food or tobacco usable flavour precursors, compounds 2‐hydroxypropyl benzoate (3a), propane‐1,2‐diyl dibenzoate (4a), 2‐hydroxypropyl cinnamate (3b) and propane‐1,2‐diyl (2E,2′ E)‐bis(3‐hydroxypropyl cinnamate) (4b) were synthesized by transesterification propanediol with vinyl benzoate and vinyl cinnamate under the biological enzyme Novozym435. The structures of the propanediol esters were characterized using nuclear magnetic resonance (1H NMR, 13C NMR), infrared spectroscopy (IR) and high‐resolution mass spectrometry (HRMS). The hygroscopicity and moisture retention capacity of reconstituted tobacco shreds with the synthesized propanediol were explored by 100 h hygroscopic desorption assay, model validation and low‐field nuclear magnetic resonance imaging (LF‐NMR). The results showed that the bound water content of 3a and 3b was lower than that of propanediol and higher than that of the control under both low (RH = 32%) and high (RH = 84%) humidity conditions. In addition, pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS) technique was applied to investigate the thermal behaviour of 3a and 3b. Four and five pyrolysis products were formed by pyrolysis of 3a and 3b, respectively. The main pyrolysis products benzoic acid and cinnamic acid could be used as flavouring agents in food and tobacco. 3a and 3b had good moisture and humidity retention effects as well as uniform and sustained flavour release. The results of the study not only effectively improve the water absorbency of reconstituted tobacco and enhance the flavour, which is suitable for the storage and smoking process, but also provide a reference for the further development of new flavour moisturizers in the tobacco industry. [ABSTRACT FROM AUTHOR]

This paper studies the pyrolysis mechanisms of Nomex insulation paper in nitrogen and air atmospheres. The Nomex insulation paper is composed of 93% poly (m-phenylene isophthalamide) (PMIA) fibers and 7% inorganic substances based on elemental analysis. Using the thermogravimetry, it is found that the pyrolysis behaviors in nitrogen and air are similar below 770 K, with large discrepancies identified in the temperature range of 770–1073 K. The peak mass loss rate in air is 9 times higher than that in nitrogen. The kinetic analysis shows that the average activation energy (E ) in air is lower than that in nitrogen by 32% when the temperature is higher than 770 K, indicating a lower thermal stability. The PMIA fibers are found decomposing more seriously in air using SEM. Below 770 K, the functional groups of two atmospheres are mainly produced by the breakage of amide bonds and formation of aromatic nitrile. Unlike nitrogen, the organic substances in the solid residue are mostly oxidized at 1073 K in air. Consequently, the maximum productions of H2O, CO2 and CO in air are nearly 5 times higher than those of nitrogen, and the HCN generated during pyrolysis is further oxidized to NOx in air. Combining with the results of Py-GC/MS, it is inferred that the small molecules generated by the degradation of PMIA molecular chains, especially the benzene rings, will experience oxidization reactions in air atmosphere, with large amounts of H2O, CO2, CO and NOx produced. [ABSTRACT FROM AUTHOR]

• Multianalytical study of a Moche funerary mask. • ED-XRF characterization of the metal alloy with Monte Carlo simulation. • Characterization of adhesive material and its components belonging to Moche culture. • Py-GC/MS and GC/MS were used for the chemical characterization of adhesive material. • SEM-EDS and ATR-FTIR were applied to characterize inorganic filler. The aim of this paper is to characterize materials belonging to one of the masks coming from the Lord of Ucupe's tomb in the region of Lambayeque in Peru. The mask belongs to the Moche culture which lived in the north of Peru since 100 CE. Along with the study of the extraordinary metal alloy technique using X-ray fluorescence (ED XRF) integrated with the Monte Carlo simulation, this paper investigates the blackish material used as an adhesive for its inlaid eyes. This material was analysed through the ATR FT-IR and characterized through Py-GC/MS and GC/MS for the organic components and SEM-EDS for the inorganic components. The chemical characterization of the adhesive material coming from this type of artefact, based on our knowledge of current literature, is the first on this material and allows us to take a further step into the understanding of the constituents used for this purpose. [Display omitted] [ABSTRACT FROM AUTHOR]

Tamarind seed husk biomass has been explored to study its slow pyrolysis behaviour and potential for bio-oil and biochar production. No study has been reported on the slow pyrolysis of seed husk of tamarind with detailed characterisation of pyrolysis products and in-depth investigations into the breaking pathways using Py-GC/MS. The slow pyrolysis was conducted in a lab-scale glass tubular reactor from 300 to 450 ℃ at a heating rate of 10 ℃/min in a nitrogen atmosphere. An optimised quantity of bio-oil (maximum yield: 38.8 wt.%) was obtained at 400 ℃ at a conversion of 67.1 wt.%, and biochar yield was 32.9 wt.% from slow pyrolysis. Different characterisation techniques were used for slow pyrolysis bio-oil and biochar analysis, such as GC–MS, FTIR, 1HNMR, XRD, SEM and proximate analysis. GC–MS analysis indicated the phenolic-rich nature of the bio-oil with various functionalities. However, more profound insights into its decomposition pattern have been provided using flash pyrolysis via an analytical tool, i.e., Py-GC/MS, which demonstrated breaking patterns of biomass framework and enabled the mechanism to be outlined. [ABSTRACT FROM AUTHOR]

The addition of glycerol, a traditional humectant, during the storage of reconstituted tobacco accelerated the deterioration of product quality due to the excessive absorption of moisture from the air by the tobacco and glycerol, which have strong hygroscopic properties. Therefore, it is crucial to develop a new humectant with moderate moisture resistance properties. In this study, a series of compounds glycerol esters were synthesized by transesterification reaction with vinyl benzoate and vinyl cinnamate via Novozym 435 using glycerol as a starting material. Nuclear magnetic resonance (1H NMR, 13C NMR), infrared spectroscopy (IR), and high resolution mass spectrometry (HRMS) were used to confirm the structure of synthesized glycerol esters. The target compounds were added to the reconstituted tobacco shreds for 100 h hygroscopic desorption assay, model validation, moisture proof index and moisture retention index. The hygroscopicity and moisturizing ability was assessed using water activity and low-field nuclear magnetic resonance (LF-NMR). It showed that 3a (2,3-dihydroxypropyl benzoate) and 3b (2,3-dihydroxypropyl cinnamate) possessed better moisture absorption and moisturizing effect. In addition, thermogravimetric analysis (TG) and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) techniques were applied to study the thermal behavior of 3a and 3b. These results indicated that the target compounds (3a and 3b) had good moisture absorption and moisture retention effects, high temperature stability and thermal properties for flavour release. They could effectively improve the water absorption, enhance the flavour of reconstituted tobacco, and were suitable for use in the storage and smoking process of reconstituted tobacco.

With the extraction of essential oils, a large amount of residual biomass is produced and they can be a good source of functional chemicals/energy. In this study, Py-GC/MS and slow pyrolysis of eucalyptus, mentha, and palmarosa were performed at various temperatures ranging from 300–450 °C to understand the distribution and characterization of the products. Under slow pyrolysis conditions, maximum bio-oil yield for eucalyptus (50.6 wt.%) and palmarosa (42.6 wt.%) was observed at 400 °C; however, for mentha (39.5 wt.%), it was observed at 450 °C. From bio-oil analysis, mentha showed a maximum area% of carbonyls (47.72%); however, phenolics were present in maximum area% in eucalyptus (63.82%) and palmarosa (46.39%). Eucalyptus bio-char showed a higher surface area as compared to the other bio-chars. [ABSTRACT FROM AUTHOR]

With urban dry and wet waste classification utilized, kitchen waste is sorted out and used for achieving anaerobic biogas, in which biogas solid residue is produced meanwhile. The purpose of this article is to clarify the pyrolysis characteristics of the biogas solid residue using thermo-gravimetric analyzer and Py-GC/MS. The main research results include: (1) The dried biogas solid residue sample has more volatile matter, accounting for 62%.The ash accounting for 37.52%. (2) There are two dominant pyrolysis peaks in thermal gravimetric curves of biogas solid residue, located at low temperature about 200–300 °C. The lower activation energy of pyrolysis rate under 100–250 oC is related to the previous anaerobic digestion process. The third peak position occurs at 750 °C due to calcination of CaCO3 in ash. (3) The amount of alcohols and acid in pyrolysis gas increases first and then decreases with the increase of temperature. The pyrolysis of ether organics mainly occurs at lower temperature, 200 °C. Those productions are assumed to be derived from lipid degradation during pyrolysis. (4) The ash of biogas solid residue obtained under 400 oC is rich in Na, K and Cl. A proper approach could convert biogas solid residue to more amount of pyrolysis gas, keeping the temperature under 600 °C. And most Na, K and Cl retain in the residue, as beneficiates the biogas quality and favors the following-up combustion behavior avoiding slagging problem in combustion chamber. [ABSTRACT FROM AUTHOR]

Catalytic pyrolysis of date palm seeds (DPS) has been carried out in a pyroprobe connected online with a GC/MS. The effect of a HZSM-5 zeolite on the product distribution has been studied at 450 and 500 °C by using different catalyst/biomass mass ratios (1, 2, 5) and that of a dolomite catalyst at 450 °C using a catalyst/biomass mass ratio of one. Product distributions have been monitored and their trends explained based on the properties of the catalysts used. The HZSM-5 promotes the formation of incondensable gases and aromatic hydrocarbons due to its high acidity and shape selectivity. The concentrations of incondensable gases and hydrocarbons increase markedly with the catalyst/biomass mass ratio, with their peak area percentages ranging from 23.6 to 54.1% and from 7.1 to 24.5%, respectively. At the same time, a significative reduction in the amount of acids, ketones, phenols, furans, and anhydrosugars has been determined. The dolomite catalyst enhances ketonization reactions, which leads to a significant increase in the content of ketones, accounting for a value of around 27%. [ABSTRACT FROM AUTHOR]

In this paper, the possibility of detecting polymers in plastic mixtures and extruded blends has been investigated. Pyrolysis–gas chromatography/mass spectrometry (py-GC/MS) allows researchers to identify multicomponent mixtures and low amounts of polymers without high spatial resolution, background noise and constituents mix interfering, as with molecular spectrometry techniques normally used for this purpose, such as Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy and differential scanning calorimetry (DSC). In total, 15 solid mixtures of low-density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), polyamide (PA) and polycarbonate (PC) in various combinations have been qualitatively analyzed after choosing their characteristic pyrolysis products and each polymer has been detected in every mix; thus, in extruded blends of high-density polyethylene (HDPE), PP and PS had varying weight percentages of the individual constituents ranging from 10 up to 90. Moreover, quantitative analysis of these polymers has been achieved in every blend with a trend that can be considered linear with coefficients of determination higher than 0.9, even though the limits of quantification are lower with respect to the ones reported in the literature, probably due to the extrusion process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Isoconversional, MDA and IPR methods where studied for MSW pyrolysis kinetics. • Activation energy: Biomass components ∼ 240 kJ/mol, Plastic fraction ∼ 250 kJ/mol. • Biomass components degradation obeys a third order kinetic (F3). • Plastic pyrolysis follows a first-order kinetic (F1). • Py-GC/Ms identifies compounds produced in each step during MSW pyrolysis. The present study endeavors to establish a comprehensive kinetic analysis of Municipal Solid Waste residue pyrolysis. As the sample exhibits four distinct degradation stages, it has been carried out by adopting a multi-step process behavior. Different approaches have been compared, including five isoconversional methods (Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall, Starink, Friedman and Advanced integral Vyazovkin), Mathematical Deconvolution Analysis, and Independent Parallel Reaction Model. The study focuses on the two active pyrolysis steps, the first one corresponds to the biomass components between 150 and 400 °C, with the decomposition peak between 300 and 350 °C, whereas the second corresponds to the plastic fraction with temperature ranging between 400 and 520 °C. The activation energy values obtained from the different kinetic methods for both steps are estimated at 240 and 250 kJ/mol, respectively. It was observed that the biomass components degradation obeys a third-order kinetic model, while the plastic fraction follows a first-order kinetic model. The analytical pyrolysis of the two main stages allows for the identification and semi-quantification of the compounds produced during municipal solid waste pyrolysis. Through analytical pyrolysis, it has been determined that up to 64 % of hydrocarbons are produced, of which 24 % correspond to aromatic compounds. Meanwhile, 20 % of oxygenated compounds were obtained, with ketones, furans, and acids being the most predominant families. [ABSTRACT FROM AUTHOR]

Some painted pottery figurines were excavated from the tomb of Qibi Ming of the Tang Dynasty. A series of analytical techniques were employed to understand the craftsmanship of these painted pottery figurines. The pigment, cross-section, adhesive, and firing temperature were analyzed using microscopy (OM), energy X-ray fluorescence spectrometry (EDX), micro-Raman spectroscopy, pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS), and a dilatometer (DIL). The results demonstrated that the surface of the pigment layers had degraded to different degrees. The pigment particles were litharge, gypsum, malachite, cinnabar, hematite, minium, white lead, and carbon black. The cross-sectional images show that the painted layer of figurines 10-0966 and 10-0678 included a pigment layer and a preparation layer. The preparation layer of both pigments was lead white. Animal glue was used as an adhesive. The firing temperature of the pottery figurines was likely 1080 °C. This study can provide more accurate information with regard to the composition of the raw materials utilized in the making of these artifacts and support the selection of appropriate substances for the purposes of conservation and restoration of the painted pottery figurines. [ABSTRACT FROM AUTHOR]

This paper presents scientific investigations into the materiality and aging behavior of a copy of Dieter Roth's multiple POEMETRIE (1968), mainly made of p-PVC components and minced meat, with the aim of informing conservation-restoration strategies. The main issues were represented by plasticizer migration, fat diffusion, and leakage, which led to the formation of a sticky surface layer. Replicas of p-PVC without minced meat were prepared and artificially thermally aged, while several techniques were used to investigate both the artwork and the replicas in terms of materials and degradation state. These include UV/Vis imaging, pH measurements, FTIR-ATR, and Py-GC/MS. In addition to showing that p-PVC-based materials composed of slightly different plasticizers were affected by similar degradation pathways (i.e., plasticizer migration, yellowing, etc.), this study reports that fat components were also shown to be unstable, resulting in migration/leakage in different directions, where their degradation amplified that of the p-PVC bags. This work represents a first study of plasticizer migration and fat diffusion in the art and conservation context. Also, an ammine-wax type of lubricant was identified in the most recent p-PVC formulations as the replicas selected for this study, thus providing an important source of information in different polymer-based research areas. [ABSTRACT FROM AUTHOR]

The thermo-kinetics of pyrolysis and product distribution of facemasks, as a blend of filter layers were explored in this study. Pyrolysis products were studied using Py-GC/MS at 550 °C for 30 s, resulting in predominantly aliphatic hydrocarbons (82.6%): alkanes (34.5%) and alkenes (48.1%). Notable gaseous products identified include propene, 2-methyl pentane, and 2,3-dimethyl-1-pentene, while the dominant species among the cycloalkanes were 1,2,3,5-tetraisopropylcyclohexane and 1,3,5-trimethylcyclohexane. Furthermore, we developed a chemical reaction mechanism to describe the main products formed during pyrolysis. Besides, the activation energy was predicted using model-free methods namely FR (214.2 kJ/mol), KAS (200.5 kJ/mol), and FWO (200.6 kJ/mol), as a function of conversion. The Coats – Redfern (CR) model-fitting method revealed that the pyrolysis reaction mechanism within the temperature range of 400 – 550 °C (pyrolysis active zone) belonged to one-dimensional diffusion and contracting cylinder model. The reliability of these results was further affirmed using the Criado method, showing agreement between the experimental and theoretical master plots. The thermodynamic parameters for facemask degradation indicated an endothermic process (ΔH = 205.5 kJ/mol, ΔG = 182.4 kJ/mol, and ΔS = 0.03 kJ/mol·K). To predict weight loss during facemask pyrolysis, we developed an artificial neural network (ANN) model that considered heating rate and temperature as inputs. The most efficient model structure involved an ANN with 2 input layers (2 neurons each), 2 hidden layers (each with 10 neurons), and an output layer (1 neuron). This study is crucial for advancing our understanding of the theoretical aspects of polymeric waste pyrolysis.

Abstract In the present work a simple enzymatic approach (Novozym 435) for transesterification to synthesize pyrrole esters was reported. To generate the best reaction conditions, which resulted in the optimum yield of 92%, the effects of lipase type, solvent, lipase load, molecular sieves, substrate molar ratio of esters to alcohol, reaction temperature, reaction duration, and speed of agitation were evaluated. The range of alcohols was assessed under optimal circumstances. The spectrum observations conclusively demonstrated that the compounds could be generated with high yield under the circumstances utilized for synthesis. The odor characteristics of the pyrrolyl esters obtained were examined by gas chromatography–mass spectrometry-olfactometry (GC–MS–O). Among them, compounds of benzhydryl 1H-pyrrole-2-carboxylate (3j), butyl 1H-pyrrole-2-carboxylate (3k) and pentyl 1H-pyrrole-2-carboxylate (3l) present sweet and acid aroma. In addition, the thermal degradation process was further studied using the Py–GC/MS (pyrolysis–gas chromatography/mass spectrometry), TG (thermogravimetry), and DSC (differential scanning calorimeter) techniques. The outcomes of the Py–GC/MS, TG, and DSC techniques show that they have excellent thermal stability.

Cangjie Temple was built to commemorate Cangjie, the legendary inventor of Chinese characters. It stands as one of the few remaining temples in China dedicated to the invention and creation of writing. In this study, the material properties of wooden paintings from the Cangjie temple were characterized using Polarized Light Microscopy (PLM), Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Micro-confocal Raman Spectroscopy, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC/MS). It was confirmed that the pigments of the paintings included cinnabar, lapis lazuli, lead white, Paris green, and carbon black. The proteinaceous glue was used as an adhesive in the pigment samples, with tung oil likely being utilized as a primer for the wooden structures before painting. This study not only provides valuable data support for the conservation and restoration of the architectural features of Cangjie Temple but also provides useful reference for the maintenance and inheritance of similar ancient buildings.

The pyrolysis performances and reaction kinetics of pine needles (PN) were investigated by integrating thermogravimetric analysis, Fourier transform infrared spectroscopy, and pyrolysis-gas chromatography/mass spectrometry. The average activation energy of PN was estimated to be 183.2 kJ/mol by Kissinger Akahira Sunose (KAS) and 183.8 kJ/mol by Flynn Wall Ozawa (FWO), respectively at heating rates of 10, 20, and 40 °C/min. The pyrolysis of PN was found to be more efficient at the lower heating rates, while increased heating rates promoted the reaction. Using the King-Kai (K-K) method, the activation energies of hemicellulose, cellulose, and lignin were calculated to be 156, 165, and 172 kJ/mol, respectively. The descending order of evolving gases and functional groups from PN was found to be CO2, C=C, C=O, H2O, CH4, and CO. The main pyrolytic by-products identified were hydrocarbons, phenols, alcohols, ketones, and aldehydes. The determination of kinetic parameters provides fundamental information for predicting the rates at which chemical reactions occur. This study demonstrates the potential of PN as a suitable source for bioenergy.

In Southern Brazil, exotic species as Acacia (A) and Eucalyptus (E) are often planted over native pasturelands and may change bulk soil organic matter (SOM) composition as verified in our previous study with Cambisols (0–5 cm). Here we aimed to follow the impact of seven-year A and E plantation on the composition of the free light- (FLF), occluded light- (OLF) and heavy fraction (HF) of SOM along the soil profile. We hypothesized that A and E may have shifted the molecular composition and carbon (C) stocks (Cs) of SOM fractions, at least at 0–5 cm; with stronger shifts caused by A due to greater E litter recalcitrance. Litter and soil samples (0–20 cm) were collected at A and E and neighboring native pasturelands without A (WA) and without E (WE). Litter, FLF, OLF and HF samples were subjected to C, nitrogen (N), pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) and lipid biomarkers analysis. In E soil, the Cs of FLF at 0–5 cm (0.5 Mg ha−1) and OLF at 5–10 cm (1.7 Mg ha−1) were 194 and 70 % greater than in WE, whereas in A soil the Cs of OLF at 0–5 cm (0.2 Mg ha−1) was 44 % lower than in WA. Nevertheless, A changed more remarkably the composition of SOM fractions, confirming our hypothesis partially, likely due to greater A litter biodegradability (polysaccharides abundance) compared to E. The contribution of A litter to FLF (0–10 cm) was evidenced by abundance of long chain and the predominance of odd-over-even n-alkanes (particularly >C29), and to OLF (0–20 cm) by the greatest abundance of n-alkanes at C31, resembling A litter. Loss of C and N of OLF in A compared to WA (0–5 cm) was compensated by fresh A litter additions to FLF and OLF and microbial-derived compounds association to soil minerals, equaling soil Cs in A and WA. The lower soil N stock in A compared to WA likely resulted from depletion of occluded microbial-derived N-compounds, supposedly reflecting the breakdown of soil aggregates at forest plantation. The increase of Cs in FLF and OLF of E compared to WE soil was associated with increased abundance of aromatics and n-alkane/alkenes and decrease of fatty acids. Similar patterns of n-alkanes observed for OLF of E and WE soil confirmed the incipient contribution of E litter to OLF. Conversion of these pastures to A and E modifies SOM composition and protection, requiring policies in view of the highly invasive potential and possible negative implications of A and E to native pasture regeneration.

Particulate matter (PM) is increasingly affecting the social-economic development of countries. An increase in PM2.5 concentration increases susceptibility to cardiovascular and respiratory diseases and cancer. Tire wear particles (TWP) contribute to airborne PM. In the present work, we investigated the variation in the concentration of TWP of 3F > 2F. A good air ventilation system can be recommended to reduce TWP2.5 concentrations in indoor parking garages.

Inland lakes play an important role as habitats for local species and are often essential drinking water reservoirs. However, there is limited information about the presence of microplastics (MPs) in these water bodies. Thirteen sediment samples were collected across a Danish urban lake to map MPs, including tyre wear particles (TWP). The lower size detection limit was 10 µm. MPs were quantified as counts, size, and polymer type by Fourier-transform infrared microspectroscopy (µFTIR) and mass estimated from the 2D projections of the MPs. As TWP cannot be determined by µFTIR, counts and sizes could not be quantified by this technique. Instead, TWP mass was determined by pyrolysis gas chromatography mass spectrometry (Py-GC/MS). The average MP abundance was 279 mg kg−1 (µFTIR), of which 19 mg kg−1 (Py-GC/MS) were TWP. For MPs other than tyre wear, the average MP count concentration was 11,312 counts kg−1. Urban runoff from combined sewer overflows and separate stormwater outlets combined with outflow from a wastewater treatment plant were potential point sources. The spatial variation was substantial, with concentrations varying several orders of magnitude. There was no pattern in concentration across the lake, and the distribution of high and low values seemed random. This indicates that large sampling campaigns encompassing the entire lake are key to an accurate quantification. No preferential spatial trend in polymer characteristics was identified. For MPs other than TWP, the size of buoyant and non-buoyant polymers showed no significant difference across the lake, suggesting that the same processes brought them to the sediment, regardless of their density. Moreover, MP abundance was not correlated to sediment properties, further indicating a random occurrence of MPs in the lake sediments. These findings shed light on the occurrence and distribution of MPs, including TWP, in an inland lake, improving the basis for making mitigation decisions.

This study was the first attempt to investigate pyrolysis of suppressed and healthy Scots pine (Pinus Sylvestris Ledeb.) wood growing in Central Siberia (the forest-steppe zone of Krasnoyarsk Region) using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR). To describe the post-pyrolysis parameters of lignin and cellulose molecular structure, the method of pyrolytic gas chromatography-mass spectrometry (Py-GC/MS) was applied. A combination of integrated TG-FTIR method with Py-GC/MS applied for studying the wood of suppressed Scots pine allowed us to take a new look at rot-induced changes of the wood chemical composition. The results obtained by TG-FTIR method and by Py-GC/MS method are in good agreement with each other, showing that rot fungi cause the depletion of the aromatic component in the wood of suppressed Scots pine. A detailed study of the holocellulose fraction revealed an increase in the relative content of cyclopentenones, sugars, and a decrease in the relative content of furans in samples of the wood of suppressed Scots pine. It has been established that benzenes, phenols, guaiacyl lignin fragments, and syringyl lignin fragments are destroyed in samples of suppressed trees when exposed to a fungal infection. The use of these methods will help to identify trees affected by a fungal infection at an early stage that cannot be determined visually. [ABSTRACT FROM AUTHOR]

Biodegradable material is a kind of polymer material which has no pollution to the environment. It has been used in food packaging, medical treatment, agriculture and other industries. However, the production cost of biodegradable materials is high and the physical properties are defective, which affects their wide application in various fields. The types and properties of biodegradable materials are reviewed. The advantages and disadvantages of spectroscopy, nuclear magnetic resonance and chromatography and mass spectrometry in the identification of biodegradable materials are compared. It is pointed out that the material characterization of biodegradable materials and the analysis methods of impurities are the key research contents, so as to provide reference for the material analysis of biodegradable materials. [ABSTRACT FROM AUTHOR]

Easily soluble organic components in Santanghu long flame coal (SLFC) from Hami (Xinjiang, China) were separated by CS2 and acetone mixed solvent (v/v = 1:1) under ultrasonic condition, and the extract residue was stratified by carbon tetrachloride to obtain the light raffinate component (SLFC-L). The effect of solvent treatment on the composition and structure of the coal and its rapid pyrolysis products was analyzed. Solvent treatment can reduce the moisture content in coal from 9.48% to 6.45% and increase the volatile matter from 26.59% to 28.78%, while the macromolecular structure of the coal changed slightly, demonstrating the stability of coal's complex organic structure. Compared with raw coal, the relative contents of oxygen-containing functional groups and aromatic groups in SLFC-L are higher, and the weight loss rates of both SLFC and SLFC-L reached the maximum at about 450 °C. In contrast, the loss rate of SLFC-L is more obvious, being 33.62% higher than that of SLFC. Pyrolysis products from SLFC at 450 °C by Py-GC/MS are mainly aliphatic hydrocarbons and oxygenated compounds, and the relative contents of aliphatic hydrocarbons decreased from 48.48% to 36.13%, while the contents of oxygenates increased from 39.07% to 44.95%. Overall, the composition and functional group in the coal sample were changed after solvent treatment, resulting in a difference in the composition and distribution of its pyrolysis products. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of catalyst support material type on the pyrolysis products of biomass. For this purpose, ZSM-5 was selected as a commercial catalyst support material, while bio-char obtained from biomass was selected as a sustainable support material. Silver poplar (SP) was used in both bio-char production and pyrolysis reactions. Primarily, biomass characterization was performed. It was determined that carbon content of SP is suitable for the production of porous carbonaceous material as 52.4%wt. In addition, the high volatile matter content (75.48%wt.) and the low ash content (9.38%wt.) showed that SP was a suitable raw material for pyrolysis method. Cobalt loading to ZSM-5 and biochar was applied by dry impregnation method. Cobalt was successfully loaded onto the support material with the dry impregnation method, which was used for the first time for metal loading to biochar. Thus, Co/SPB catalyst was produced that was both inexpensive and provided less waste water production compared to other methods has been obtained. Commercially purchased ZSM-5, biochar obtained from SP and their 15%wt. cobalt loaded forms were characterized using BET, XRD and ICP-OES techniques. When cobalt was loaded to support materials, the specific surface area of biochar increased from 2.07 m2/g to 95.29 m2/g, while the specific surface area of ZSM-5 decreased from 414.54 m2/g to 343.05 m2/g. Also, it was seen that the pore size decreased if metal was loaded on the support materials. The pore size of the Co/SPB and Co/HZSM-5 samples were 6.5 nm and 2.2 nm, respectively. According to the XRD analysis results, it was specified that the cobalt onto the catalyst surface was in the Co3O4 crystal structure. The ICP-OES results were also showed that cobalt has been successfully loaded onto the catalysts. A significant increase in the amount of alcohol in the bio-oil was specified with using the Co/SPB catalyst in the pyrolysis of SP. The alcohol content increased as the amount of Co/SPB catalyst increased from 10 wt% to 20 wt%. According to this result, Co/SPB catalyst can be used in the production of bio-alcohol from biomass. While Co/HZSM5 catalyst was used in the pyrolysis reactions of SP, an increase in aromatic and aliphatic hydrocarbon content was determined. Co/HZSM5 catalyst can be utilized in the production of valuable chemicals, commercially. In addition, oxygenated compounds, which were undesirable products in the evaluation of bio-oil as a bio-fuel, were reduced in the bio-oil with catalytic performance. [ABSTRACT FROM AUTHOR]

In order to investigate the evolution of Chinese lacquering techniques, seven pieces of lacquer Lian from the Warring States Period to the Yuan Dynasty (475 BC–1368 AD) were analyzed by means of cross-section observation, Raman spectroscopy (RS), and thermally assisted hydrolysis and methylation pyrolysis coupled with gas chromatography/mass spectroscopy (Py-GC/MS). The results revealed that the lacquer Lian consisted of a three-layer structure, encompassing a pigment layer on the surface, an undercoat layer in the middle, and a ground layer. The red mineral pigment utilized was cinnabar, while a combination of Chinese lacquer and drying oil served as the primary organic material. Although lacquering techniques had undergone minimal changes from the Warring States Period to the Yuan Dynasty, the species of drying oil had changed, based on the fact that boiled tung oil was found in the ground layer of lacquerware from the Song Dynasty and the Yuan Dynasty. The present research provides direct evidence for the inheritance and development of Chinese lacquer technology. [ABSTRACT FROM AUTHOR]

In the present work a simple enzymatic approach (Novozym 435) for transesterification to synthesize pyrrole esters was reported. To generate the best reaction conditions, which resulted in the optimum yield of 92%, the effects of lipase type, solvent, lipase load, molecular sieves, substrate molar ratio of esters to alcohol, reaction temperature, reaction duration, and speed of agitation were evaluated. The range of alcohols was assessed under optimal circumstances. The spectrum observations conclusively demonstrated that the compounds could be generated with high yield under the circumstances utilized for synthesis. The odor characteristics of the pyrrolyl esters obtained were examined by gas chromatography–mass spectrometry-olfactometry (GC–MS–O). Among them, compounds of benzhydryl 1H-pyrrole-2-carboxylate (3j), butyl 1H-pyrrole-2-carboxylate (3k) and pentyl 1H-pyrrole-2-carboxylate (3l) present sweet and acid aroma. In addition, the thermal degradation process was further studied using the Py–GC/MS (pyrolysis–gas chromatography/mass spectrometry), TG (thermogravimetry), and DSC (differential scanning calorimeter) techniques. The outcomes of the Py–GC/MS, TG, and DSC techniques show that they have excellent thermal stability. [ABSTRACT FROM AUTHOR]

Summary: Background: Microplastics (MPs) have garnered widespread attention because of their presence in human placenta, stool, and even blood. Ingestion is considered the major route of human exposure to MPs. It has been found that the consumption of food and water is associated with more MP abundance in human stools. The usage of plastic containers, particularly feeding bottles, may be a major contributor to MP contamination. However, human exposure to MPs and potential factors that influence exposure, especially for preschoolers, remains largely unknown. When exposed to MPs, mice exhibited gut microbiota dysbiosis, including alterations in diversity indices, a decreased relative abundance of probiotics and an increased abundance of pathogenic bacteria. Such results have also been observed in human gut in vitro models, however, the actual association between MP exposure and human intestinal microbiota remains unclear. Therefore, this study aimed to evaluate MP concentrations in preschoolers’ stools, explore possible dietary factors that influence preschooler exposure to MPs, and investigate their potential association with the gut microbiota. Methods: A cross-sectional study was conducted in Xiamen, China in October 2022. We investigated the feeding behaviours and dietary habits of preschool children. A total of 69 couples of stool samples were collected and analyzed for MPs test and gut microbiota analysis. Pyrolysis-gas chromatography coupled with mass spectrometry (Py-GC/MS) was used for quantifying 11 types of MPs. The gut microbiota composition was analyzed by 16S rRNA gene sequencing. Findings: The results showed that only polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyethylene (PE), and polyamide 6 (PA6) were detected in 85.5% stool samples, with concentrations of 317.4 (152.0, 491.9) μg/g dw, 299.0 (196.1, 619.9) μg/g dw, 206.2 (154.1, 240.3) μg/g dw, and 17.9 (13.4, 18.6) μg/g dw, respectively. The median estimated daily intake (EDI) for preschoolers was 425.9 (272.5, 762.3) μg/kg-bw/d. Dairy intake may influence MP concentration in preschoolers’ stools, and the usage of feeding bottles may be a specific source of MP contamination. Moreover, higher PVC concentrations were observed in the stools when the children took more time to eat a meal. MP exposure was inversely associated with alpha indices and possibly affected certain probiotic taxa, such as Parabacteroides and Alistipes, in preschool children. Interpretation: Our data provided baseline evidence for MP exposure doses and potential dietary factors that may influence MP exposure in preschoolers. These findings supported the perspective that MP exposure might be associated with the disturbance of gut microbiota. Further studies focusing on sensitive populations with larger sample sizes are needed. Funding: This study was funded by the National Natural Science Foundation of China (grant number: 82003412), the Shanghai Municipal Health Commission (grant number: 20214Y0019), and the Project of Shanghai Municipal Financial Professional foundation (Food Safety Risk Assessment) (grant number: RA-2022-06).

Acrylonitrile butadiene styrene (ABS) is a thermoplastic polymer widely used in several everyday life applications; moreover, it is also one of the most employed plastics in contemporary artworks and design objects. In this study, the chemical and thermal properties of an ABS-based polymer and its photo-degradation process were investigated through a multi-analytical approach based on thermal, mass spectrometric and spectroscopic techniques. LEGO® building blocks were selected for studying the ABS properties. First, the composition of unaged LEGO® bricks was determined in terms of polymer composition and thermal stability; then, the bricks were subjected to UV–Vis photo-oxidative-accelerated ageing for evaluation of possible degradation processes. The modifications of the chemical and thermal properties were monitored in time by a multi-technique approach aimed at improving the current knowledge of ABS photodegradation, employing pyrolysis online with gas chromatography and evolved gas analysis, coupled with mass spectrometric detection (Py-GC-MS and EGA-MS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and corroborated by external reflection FT-IR spectroscopy. The multimodal approach provided new evidence on the two-step degradation pathway proposed for ABS, defining molecular markers for polybutadiene oxidation and styrene-acrylonitrile depolymerization. Moreover, the results highlighted the feasibility of correlating accurate compositional and thermal data acquired by bulk techniques with external reflection FT-IR spectroscopy as a non-invasive portable tool to monitor the state of conservation of plastic museum objects in-situ. [ABSTRACT FROM AUTHOR]

Sengon wood (Paraserianthes falcataria) is widely used in the sawmill industry. It produces waste that has not received proper handling, furthermore, innovations are needed to solve this problem, as an example as a precursor for catalyst material. This study aimed to synthesize and characterize a Co/activated carbon as a catalyst for LDPE pyrolysis. The method used is the carbonization and activation of sengon wood at 400°C and 800°C using steam, respectively. Carbon was then impregnated with 5% Co(NO3)2·6H2O. Catalyst evaluation was carried out through proximate analysis, benzene adsorption, iodine number, methylene blue adsorption, and catalyst acidity. Functional group content, morphology, crystal phase, and surface area were analyzed using FTIR, SEM-EDX, XRD, and SAA. For application, the ratio of feed: catalyst is 1:1;1:5; and 1:10. The results showed that the quality of activated carbon was 90% close to Indonesian National Standard quality. The catalyst acidity was 10,555 mmol/g with a metal crystal size of 0.56nm. Surface morphology had opened pores with the pore size, pore volume, and surface area of 2.69 nm, 0.263 cm³/g, and 329.99 m²/g respectively. LDPE cracking using a catalyst resulted in aliphatic, aromatic, and alicyclic hydrocarbon products of 48.86, 15.26, and 12.55%. Co/activated carbon catalyst has an excellent prospect for use as an LDPE cracking catalyst as a green chemical application. [ABSTRACT FROM AUTHOR]

The ratio of monomeric units is one of the main characteristics of lignin, which affects the possibilities and strategies for further processing. Pyrolytic and thermal desorption decomposition of lignins followed by mass detection of macromolecule fragments are the most common methods for determining the amount of lignin structural units. Two methods of thermal decomposition of lignin were studied: thermal desorption–GC/MS (TD–GC/MS) and pyrolysis–GC/MS (Py–GC/MS). It was noted that, when using different thermal decomposition modes, the composition of the products changes, which affects the accuracy of determining the amount of lignin structural fragments. This article investigated the influence of the sample weight, the thermal decomposition temperature, and the duration of the process in various modes on the quantitation of the lignin structural units. The optimal process conditions were established. It was shown that the DS–Py–GC/MS with cryofocusing, a sample weight of 0.2–0.4 mg, and heating from 50 to 400 °C at a rate of 120 °C/min are preferable. The HSQC NMR was used as a comparison method to obtain the content of the S/G/H units. The results showed the applicability of the proposed approaches to hardwood lignins close to native. [ABSTRACT FROM AUTHOR]

In this study, both the pyrolysis and catalytic pyrolysis behaviour of chlorella were investigated using thermogravimetric analysis combined with Fourier Transform Infrared spectrum (TG-FTIR) and Py-GC/MS. The results of TG indicated the pyrolysis of chlorella was divided into three stages, and the Coats-Redfern kinetic model was used for the analysis and validation of the obtained thermal data. The regression coefficients indicated that the pyrolysis of chlorella was close to second-order reaction. The activation energy of pyrolysis of chlorella and catalytic pyrolysis of chlorella+HZSM-5, chlorella+Zn/HZSM-5 was 61.645, 59.080 and 56.808 kJ·mol−1, respectively. Combined with the data of FTIR, we found that the addition of the HZSM-5 effectively reduced the activation energy required by pyrolysis; the addition of the Zn/HZSM-5 could not only reduce the activation energy, but also reduce the yield of oxygen-containing compounds, increase the emissions of CO2, and facilitate the production of high value-added hydrocarbon products. These results were also verified by Py-GC/MS that the addition of Zn/HZSM-5 could reduce the formation of ketones and aldehydes and increase the production of nitrogen-containing compounds. Thus, through the catalytic pyrolysis of chlorella, the utilization range of chlorella can be expanded, and better bio-oil can be obtained, which will play a crucial role in the selection of available energy in the future. [ABSTRACT FROM AUTHOR]