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Abstract Background Microplastics, widely present in the environment, are implicated in disease pathogenesis through oxidative stress and immune modulation. Prevailing research, primarily based on animal and cell studies, falls short in elucidating microplastics' impact on human cardiovascular health. This cross-sectional study detected blood microplastic concentrations in patients presenting with chest pain using pyrolysis–gas chromatography/mass spectrometry and evaluating inflammatory and immune markers through flow cytometry, to explore the potential effects of microplastic on acute coronary syndrome. Results The study included 101 participants, comprising 19 controls and 82 acute coronary syndrome cases. Notably, acute coronary syndrome patients exhibited elevated microplastic concentrations, with those suffering from acute myocardial infarction presenting higher loads compared to those with unstable angina. Furthermore, patients at intermediate to high risk of coronary artery disease displayed significantly higher microplastic accumulations than their low-risk counterparts. A significant relationship was observed between increased microplastic levels and enhanced IL-6 and IL-12p70 contents, alongside elevated B lymphocyte and natural killer cell counts. Conclusion These results suggest an association between microplastics and both vascular pathology complexity and immunoinflammatory response in acute coronary syndrome, underscoring the critical need for targeted research to delineate the mechanisms of this association. Highlights 1 Blood microplastic levels escalate from angiographic patency, to angina patients, peaking in myocardial infarction patients. 2 Microplastics in acute coronary syndrome patients are predominantly PE, followed by PVC, PS, and PP. 3 Microplastics may induce immune cell-associated inflammatory responses in acute coronary syndrome patients. Graphical abstract

Polystyrene microplastics, especially those smaller than 10 μm, reduce male fertility in murine models, but whether they affect male reproduction in humans is poorly understood. Here, we studied polystyrene microplastics smaller than 10 μm in human semen samples and evaluated their toxicity to human sperm. We also tested the use of magnetic iron oxide nanoparticles to remove nanoplastics and decrease their toxicity in human sperm. Results show that human semen is contaminated by approximately 3.57 ± 0.32 μg/mL polystyrene microplastics smaller than 10 μm. Polystyrene nanoplastics of 25–100 nm penetrate and damage human sperm at semen-relevant concentrations of 5 and 50 μg of nanoplastic per mL, while 0.5–10 μm polystyrene microplastics bind to the sperm. We also found that 25-nm polystyrene nanoplastics exhibited a synergistic toxicity with bisphenol A on human sperm. Nonetheless, we observed that environmental microplastics released from disposable paper cups do not pose a significant hazard to human sperm under our conditions. Furthermore, magnetic iron oxide nanoparticles can aggregate and coprecipitate with 25-nm polystyrene nanoplastics to eliminate their adverse effects on human sperm. [ABSTRACT FROM AUTHOR]

The quantification analysis of microplastics (MPs) in bottled water, purified tap water and branded table salt was executed by double-shot pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS), and the concentration was expressed as a mass concentration, which was more suitable for the data comparison. MPs including polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), polystyrene (PS) and polyethylene (PE) were separated by filtration with glass fiber filter membranes. After being folded, the whole glass filter membrane containing MPs was transferred into a pyrolysis cup directly to avoid the sample loss during transfer. The characteristic pyrolysates were used to identify and quantify PMMA, PET, PC, PP, PS and PE. The linear relationships were found between the polymer weight amount and peak areas of each characteristic pyrolysates with the correlation coefficients larger than 0.993. The intra-day precisions of the pyrolysates for peak areas were 0.56–18.94%, and the inter-day variability was 8.47–19.88%. The recovery values of the spiked standards were in a range of 81.5–114.5%. MPs in bottled water, purified tap water and branded table salt samples were successfully quantified by the proposed Py–GC/MS method. For four brands of bottled water samples, 0.088 μg/L PET was found in one sample. PP was detected in all purified tap water samples from five brands with the concentrations between 0.028 and 0.489 μg/L, and PE was detected in purified tap water samples from two brands with the concentrations between 0.194 and 1.26 μg/L. As for nine table salt samples, PP were found in a range of 4.00–182.80 μg/100 g salt in eight table salt samples. Due to the high content of MPs in purified tap water samples and large daily consumption, the estimated daily intake (EDI) of MPs from purified tap water was calculated. The estimated daily intakes (EDIs) for adults are 2.57 ng PP/kg/d and 4.17 ng PE/kg/d from purified tap water; the EDIs for children are 5.63 ng PP/kg/d and 9.11 ng PE/kg/d from purified tap water. [ABSTRACT FROM AUTHOR]

Background: Microplastics, widely present in the environment, are implicated in disease pathogenesis through oxidative stress and immune modulation. Prevailing research, primarily based on animal and cell studies, falls short in elucidating microplastics' impact on human cardiovascular health. This cross-sectional study detected blood microplastic concentrations in patients presenting with chest pain using pyrolysis–gas chromatography/mass spectrometry and evaluating inflammatory and immune markers through flow cytometry, to explore the potential effects of microplastic on acute coronary syndrome. Results: The study included 101 participants, comprising 19 controls and 82 acute coronary syndrome cases. Notably, acute coronary syndrome patients exhibited elevated microplastic concentrations, with those suffering from acute myocardial infarction presenting higher loads compared to those with unstable angina. Furthermore, patients at intermediate to high risk of coronary artery disease displayed significantly higher microplastic accumulations than their low-risk counterparts. A significant relationship was observed between increased microplastic levels and enhanced IL-6 and IL-12p70 contents, alongside elevated B lymphocyte and natural killer cell counts. Conclusion: These results suggest an association between microplastics and both vascular pathology complexity and immunoinflammatory response in acute coronary syndrome, underscoring the critical need for targeted research to delineate the mechanisms of this association. Highlights: Blood microplastic levels escalate from angiographic patency, to angina patients, peaking in myocardial infarction patients. Microplastics in acute coronary syndrome patients are predominantly PE, followed by PVC, PS, and PP. Microplastics may induce immune cell-associated inflammatory responses in acute coronary syndrome patients. [ABSTRACT FROM AUTHOR]

The thermolysis of waste tobacco filters (WTFs) was carried out and characterized by thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The WTFs showed four distinctive derivative TG (DTG) peaks. Such distinctive DTG curves were indicative of the thermal desorption of triacetin (< 220°C), thermal desorption of glycerol tricaprylate (221-270°C), decomposition of cellulose acetate (CA, 281-400°C), and char stabilization (> 400°C). The activation energy (Ea) (223-279 kcal kg-1) in the additives desorption region (220-270°C) were higher than those (169 ± 5.1 kcal kg-1) from the WTFs at the main decomposition region of CA (281-400°C). Py-GC/MS suggested that a large amount of acetic acid (AA, 33.0 wt.%) was recovered as the major pyrogenic product stemming from WTF. An increase in AA purity up to 76.2% (except for CO2) was achieved in the 2nd Py step at 400°C after eliminating the non-target chemicals (nicotine, triacetin, glycerol tricaprylate, and 2-(decanoyloxy)propane-1,3-diyl dioctanoate) through the 1st thermal desorption (TD) step to 300°C. [ABSTRACT FROM AUTHOR]

Mountain ecosystems exhibit rapid changes in vegetation cover and climate conditions along elevation gradients, offering an ideal natural experiment to examine variations in the molecular composition of soil organic carbon (SOC) responsing to environmental change. We examined molecular composition, diversity, and network complexity of SOC using the pyrolysis-gas chromatography/mass spectrometry technology and the Shannon diversity index (SHDI) in Changbai Mountain (CBS). Results indicated that molecular composition of SOC differed greatly across different vegetation zones, which were predominated by mixed coniferous and broad-leaved forests (HJL), mixed coniferous forests (ZYL), birch forest covered (YHL), and tundra vegetation (TYD). ZYL had remarkably more abundant moieties with aromatic structures, 36% on average, than those in HJL, TYD, and YHL, 18.31%, 12.75% and 16.51% on average, respectively. O-alkyl, alkyl, and terpene compounds showed an increasing trend, whereas aromatic, lignin and nitrogen-containing compounds exhibited a notable decrease with elevation to a significant level. Either alpha diversity or beta diversity of SOC varied significantly among TYD, YHL, ZYL, and HJL, with HJL exhibiting the lowest alpha diversity. SOC from ZYL was the most complex, showing the highest number of edges and graph density. Leaf litter elements greatly regulated the molecular diversity and network complexity of SOC. Positive correlations between SHDI and SOC contents, as well as ratios of SOC to total iron, suggested that high molecular diversity promoted SOC persistence in mountain ecosystems.

The bound acrylonitrile content in nitrile rubber (NBR) was determined by pyrolysis-gas chromatography/mass spectrometry, and the effects of furnace temperature and sample amount on pyrolysis were investigated. The butadiene and acrylonitrile fragments were identified by mass spectrometry, and the relationship between peak height ratio of acrylonitrile to butadiene and content ratio of acrylonitrile to butadiene was also established. Furthermore, the test results were compared with those determined by Kjeldahl method. The experiment results showed that the butadiene and acrylonitrile fragments in NBR had good chromatographic peak shape and recognition under the conditions of pyrolysis temperature of 600 ℃ and sample mass of 0.3-0.6 mg. The peak height of acrylonitrile with extracted ion M/Z 53 was positively correlated with the content of bound acrylonitrile in NBR, and the linear correlation coefficient of quantitative curve was above 0.99. Compared with Kjeldahl method, the absolute deviation of this method for determination of bound acrylonitrile content was not more than 0.7%.

The mural paintings of the Second Tomb of the Southern Tang Dynasty in Nanjing, Jiangsu Province, which is the largest in scale during the Five Dynasties and Ten Kingdoms period in southern China, are selected as the objects of study, on the basis of optimization of the test conditions of the egg white standard samples by using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis technique. Eight inorganic mineral pigments such as calcite, lead tetroxide, ochre, cinnabar, azurite, mineral green, orpiment and realgar on the cleavage products are evaluated for the first time and a method is established for the identification of egg whites in the tomb murals. The Py-GC/MS analytical method is developed for the identification of egg whites in tomb murals. The results of the analysis of the artifact samples show that egg whites are added to the mural ground battles, mortars and pigments as cementing materials, and the results of the Py-GC/MS analysis are verified using enzyme-linked immunosorbent assay (ELISA), further demonstrating that Py-GC/MS is a reliable analytical method for egg white composition in tomb murals. This study provides a methodological reference for the study of organic binding media in tomb murals. [ABSTRACT FROM AUTHOR]

Chuju, a cultivar of Chrysanthemum morifolium, has been traditionally cultivated for over 2000 years in China for both ornamental and medicinal purposes. To date, investigations into the chemical composition of this plant have indicated that it contains compounds with extensive biological activities, although detailed information on the chemical composition of Chuju remains scarce. In the present study, the chemical compositions of Chuju flowers were investigated across five sites in the core Chuju planting area in Anhui province, China. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) was used to explore variations in flower chemical fingerprints from different Chuju planting sites. The study identified approximately 200 components in Chuju flowers and stems, including high levels of fatty acids, lipids, polysaccharides and terpenoids. Multivariate statistical analysis indicated that 16 chemical compounds were influential determinants of the chemical fingerprint and could be used to distinguish two clusters in the five core planting areas. The established Py-GC/MS analytical workflow could provide a basis for determining the chemical fingerprints of Chuju and help elucidate that products contain a reproducible content of bioactive compounds and overall quality for potential development of health and medicinal purposes., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

Particulate matters (PMs) such as PM10 and PM2.5 were collected at a bus stop and were analyzed using pyrolysis-gas chromatography/mass spectrometry to identify organic polymeric materials in them. The major pyrolysis products of the PM samples were isoprene, toluene, styrene, dipentene, and 1-alkenes. The pyrolysis products generated from the PM samples were identified using reference polymeric samples such as common rubbers (natural rubber, butadiene rubber, and styrene-butadiene rubber), common plastics (polyethylene, polypropylene, polystyrene, and poly(ethylene terephthalate)), plant-related components (bark, wood, and leaf), and bitumen. The major sources of the principal polymeric materials in the PM samples were found to be the abrasion of the tire tread and asphalt pavement, plant-related components, and lint from polyester fabric. The particles produced by the abrasion of the tire tread and asphalt pavement on the road were non-exhaustive sources, while the plant-related components and lint from polyester fabric were inflowed from the outside. [ABSTRACT FROM AUTHOR]

The surface decoration layers of Samantabhadra Bodhisattva and Thousand Hand Guanyin from Dazu Rock Carvings were examined using digital microscopy, energy-dispersive spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and pyrolysis—gas chromatography/mass spectrometry using thermally assisted hydrolysis and methylation. Gypsum was present in the preparation layer, while the painted layer included lacquer sap (urushiol). The presence of heat-bodied tung oil and resin (benzoin resin) was also detected in some painted layers. Mineral pigments were found in the painted layers, including cinnabar, lead red, orpiment, litharge, and carbon. In addition, there was a layer of gold foil on the surface of the Thousand Hand Guanyin sample. The mass percentage of gold was 96.70%. The gold foil contained gold, silver, copper, and iron as a solid solution. This study provides a reference for the study and protection of cultural relic samples from grottoes. [ABSTRACT FROM AUTHOR]

Abstract For conservation and restoration purposes, the precious historical rubbings preserved in Wuyuan Museum were studied by multi-analytical techniques including 14C radiocarbon dating, scanning electron microscopy (SEM), Pyrolysis–Gas Chromatography/Mass Spectrometry (Py-GC/MS) and Herzberg staining method. The results showed that the Py-GC/MS method is an efficient method for identifying the raw materials of paper and ink in historical rubbings simultaneously. Through Py-GC/MS analysis, five types of constituents could be detected: (1) polycyclic aromatic hydrocarbons (PAHs) from soot; (2) compounds related to tar of conifer wood: retene and methyl dehydroabietate; (3) marker compounds from the whole egg; (4) additive compounds: menthol and curcumene, which were found for the first time in ink; (5) biochemical compounds from bark paper: β-amyrin and α-amyrin. Based on the above results, the ink type, binding media and additives in ink, as well as the fiber origin of the rubbing paper could be concluded. This study could not only provide scientific support for conservation and restoration of the historical rubbings preserved in Wuyuan museum, but also give method guidance for analysis of the uncharacterized rubbings from different origins.

The carbon cycle in ecosystems is fundamentally controlled by the composition and transformation of organic molecules. Alpine wetland soils have enormous carbon storage, but they are sensitive to climate change, and can easily shift from carbon sink to carbon source. However, we currently lack understanding in molecular-chemical composition of soil organic matter (SOM) in alpine wetlands. In this study, we tried to decipher molecular-chemical features of SOM in typical alpine wetlands using the pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Results indicated that nitrogen-containing compounds were the most abundant moieties among pyrolytic products of SOM. More than 83 % of pyrolytic moieties had a molecular weight of no more than 200 Daltons and a H/C ratio of no more than 2.0. O/C ratio of most pyrolytic products were less than 0.5. A van Krevelen diagram potentially indicated that SOM in wetlands might consist of massive heterogeneous molecules where aromatic compounds and their derivatives served as the core, with aliphatic hydrocarbon molecules of varying carbon chain lengths attached externally. About 72.25 % of variances in SOM were explained by 50 pyrolytic products, of which toluene was the most important. A significantly negative relation was observed between molecular weight (MW) and abundance of pyrolytic products, while positive relations were found between H/C, O/C, and abundance of pyrolytic products. Our work implied that SOM in wetlands was mainly composed of molecules with low MW and aromatic function groups. • More than 83 % of the moieties had a molecular weight of no more than 200 Daltons. • Aromatic compounds and their derivatives served as the core of SOM in wetlands. • About 72.25 % of variances in SOM composition were explained by 50 pyrolytic products. [ABSTRACT FROM AUTHOR]

This study was conducted to establish the optimal pyrolysis process for producing high-yield and high-purity acetic acid (AA) from waste cigarette butts (CBs). The waste cigarette filters (CFs) were collected from CBs by shredding and sieving before pyrolysis. The non-isothermal pyrolysis of waste CF was studied using evolved gas analysis-mass spectrometry (EGA-MS) and double-shot pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) with tandem μ-reactor-GC/MS (TMR-GC/MS). EGA-MS of waste CF could differentiate the thermal desorption zones of tobacco additives, such as triacetin and glycerol tricaprylate, from the AA generation zone via cellulose acetate (CA) pyrolysis. The non-isothermal pyrolysis of CA, fresh CF, and waste CF from 100 °C to 400 °C at 20 °C/min resulted in AA as the primary product, with yields of 39.2 %, 34.8 %, and 36.2 %, respectively, along with the formation of additives, such as triacetin (8.8 wt% from waste CF) and glycerol tricaprylate as the main impurity. Despite the potential catalytic conversion of triacetin to AA using a mesoporous catalyst, Al-MCM-41 (SiO 2 /Al 2 O 3 : 25), the catalytic pyrolysis of waste CF did not enhance the high AA yield because of the additional conversion of AA, produced from CA in waste CF, into light hydrocarbons, reducing the AA yield. Finally, the optimized conditions for the highest quantity and quality AA production, achieving a total yield of 40.0 %, were determined to be a two-step selective catalytic conversion: 1) catalytic thermal desorption up to 300 °C using Al-MCM-41 at 350 °C and 2) non-catalytic pyrolysis for CA conversion from 301 °C to 400 °C of waste CF. • Acetic acid was produced via the two-step pyrolysis of cigarette filters. • Catalytic conversion of triacetin over Al-MCM-41 increased acetic acid yield. • Catalytic pyrolysis of cellulose acetate is improper for acetic acid production. • Selective use of catalyst increased the yield of acetic acid up to 40 %. [ABSTRACT FROM AUTHOR]

Tire wear particle has been considered as one of environmental pollution sources and its sizes are widely ranged from PM2.5 to several hundred micrometer (μm). A bus tire tread is generally composed of NR and BR. In the present work, difference in the rubber compositions of wear particles of a model bus tire tread compound (NR/BR = 80/20) depending on the particle size was investigated by the single particle analysis using Py‐GC/MS. The wear particles were obtained using a laboratory abrasion tester. The wear particles were separated by size using a sieve shaker and those of 212–500, 106–212, and 63–106 μm were used. The rubber composition of each single particle was determined using the principal pyrolysis product ratio of 4‐vinylcyclohexene and dipentene produced from BR and NR, respectively. For the wear particles of 212–500 μm, the rubber compositions were nearly the same to the bulk (the abrasion specimen) and the differences among them were small. But the rubber compositions of the wear particles of below 212 μm were different each other. Some wear particles of 106–212 μm had very high BR composition above 70 wt%. For the wear particles of 63–106 μm, some wear particles had very low BR composition of nearly to zero BR. Difference in the rubber compositions from the bulk tended to be larger by decreasing the wear particle size. The analytical results were explained by the distribution of BR in NR and abrasion position. [ABSTRACT FROM AUTHOR]

Microplastics are now recognized as a persistent and global pollutant. To quantitively measure microplastics in environmental matrices, several techniques are used including new methods using pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). In the present study, a new extraction method using microwave‐assisted extraction (MAE) combined with Py–GC/MS was developed to extract and quantify a wide range of plastic polymers, and the method was validated using different environmental matrices. This new extraction method was able to extract polyethylene, polystyrene, polypropylene, poly(methyl‐methacrylate) (PMMA), polyvinylchloride (PVC), and polycarbonate in dichloromethane with good recoveries (92.9–119.7%). The limit of detection and limit of quantification (LOQ) of the method ranged from 0.002 to 0.18 µg and from 1.2 to 5.8 µg, respectively. Intra‐ and interday repeatability values with coefficients of variation less than 25% for all polymers were obtained. Method validation also included a spike and recovery using all polymers from clean water, dirty water, and shrimp and salmon fillet samples, with recoveries of 85 to 111, 87 to 138, 81 to 122, and 50 to 151%, respectively. Finally, the method was tested on unspiked wild mussels and bottled water for proof‐of‐concept. Both polyethylene and PVC were detected and quantified in mussels, and polycarbonate and polypropylene were detected below the LOQ. For bottled water, polypropylene, polystyrene, and polycarbonate were all detected below the LOQ. We introduce a method combining MAE and Py–GC/MS as a tool for mass quantification of microplastics. This method can be used as a stand‐alone, or as a complementary method to spectroscopic techniques. Environ Toxicol Chem 2021;40:2733–2741. © 2021 SETAC [ABSTRACT FROM AUTHOR]

[Display omitted] • Estimation of micron-sized microplastics in tea infusion by Raman imaging. • Detection of submicron- and nano-sized microplastics in tea infusion by Py-GC/MS. • Woven tea bags release far fewer microplastics than nonwoven tea bags. • Pre-washing reduced 76–94% micron- and 80–87% submicron-sized microplastic. Microplastics released from plastic-based filter bags during tea brewing have attracted widespread attention. Laser confocal micro-Raman and direct classical least squares were used to identify and estimate micron-sized microplastics. Characteristic peaks from pyrolysis-gas chromatography/mass spectrometry of polyethylene terephthalate, polypropylene, and nylon 6 were selected to construct curves for quantification submicron-sized microplastics. The results showed that microplastics released from tea bags in the tea infusions ranged from 80 to 1288 pieces (micron-sized) and 0 to 63.755 μg (submicron-sized) per filter bag. Nylon 6 woven tea bags released far fewer microplastics than nonwoven filter bags. In particular, a simple strategy of three pre-washes with room temperature water significantly reduced microplastic residues with removal rates of 76 %–94 % (micron-sized) and 80 %–87 % (submicron-sized), respectively. The developed assay can be used for the quantitative evaluation of microplastics in tea infusions, and the pre-washing reduced the risk of human exposure to microplastics during tea consumption. [ABSTRACT FROM AUTHOR]

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To facilitate the reuse and recycling of polyvinyl chloride (PVC) to achieve sustainable development and new industrialization, the composition and mechanism of formation of volatiles during the flash pyrolysis of PVC were studied by thermogravimetry-Fourier transform infrared (TG-FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). TG and derivative thermogravimetry (DTG) analyses indicated two main degradation stages during flash pyrolysis of PVC, namely dehydrochlorination of PVC and decomposition of dechlorinated-PVC. Simultaneously, the FTIR results revealed that the main functional groups in the pyrolysis process were H–Cl, -C-Cl, C–H, C H, and aromatic groups. The relative content of main volatiles was determined by Py-GC/MS, and decreased in the following order: aromatics > alkenes > hydrogen chloride (HCl) > chlorinated hydrocarbons. Specifically, the relative content of aromatics was as high as 76.790–81.809%, while that of HCl was in the range of 3.016–3.096%. The carbon number distribution and the relative content of main products obtained from the flash pyrolysis of PVC at different final temperatures were also analysed. According to the experimental results, the mechanism of formation of the main volatiles based on free-radical reactions was deduced in detail. Therefore, this study provides further details for deepening the understanding of the PVC pyrolysis process. • The release characteristics of volatiles were consistent with pyrolysis behavior. • HCl, chlorinated hydrocarbons, alkenes, and aromatics were the main volatiles. • Effect of temperature on the distribution of volatile products was revealed. • The formation mechanism of the main volatiles was free-radical reactions. [ABSTRACT FROM AUTHOR]

Waste and low-cost lignocellulosic biomasses are well studied and widely used as raw materials for porous carbon adsorbents. Much less attention is given to the exploration of the potential of marine biomasses, though these materials contain also nitrogen, which—if preserved during the processing—has a beneficial influence on the sorption properties of the porous carbon obtained. Here, we report a multi-technique investigation into the conversion of crab shell to porous carbon adsorbent. Thermogravimetry and pyrolysis-GC/MS studies were used to reveal the thermal degradation of this natural polymer and follow the decomposition process through the identification of the products. Almost 40 various volatile degradation products were distinguished released at 500 °C pyrolysis temperature. Based on the TGA/DTG results, two temperatures, 350 and 500 °C, were selected to obtain pyrolytic samples in macroscopic quantities in order to characterize the morphology and surface chemistry of the solid fraction. More than 50% of the nitrogen atoms were still in the carbonaceous matrix after the 500 °C pyrolysis in the C–N=C, C–NH and 3C–N-type bonds. The ash content < 1% included hydroxylapatite-type crystalline matter. Based on these results, we may conclude that crab shells have a high potential as precursor of nitrogen-containing biochar. [ABSTRACT FROM AUTHOR]

Highlights • Catalytic fast pyrolysis of pretreated pine wood was studied by Py-GC/MS and PCA. • PCA showed how feedstock and pyrolysis conditions affected pyrolysis products. • Temperature and catalyst loading were more important than biomass pretreatment. • Acid-leaching pretreatment slightly lowered the proportion of aromatic products. • The effects of acid-leaching and torrefaction were greatest in non-catalytic pyrolysis. Abstract Non-catalytic and catalytic pyrolysis of pretreated pine wood was conducted using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Biomass pretreatment included acid-leaching, torrefaction, and acid-leaching followed by torrefaction. Forty-five pyrolysis products were identified in the Py-GC/MS chromatograms and their peak area data evaluated by principal component analysis. In non-catalytic pyrolysis, acid-leaching pretreatment enhanced the levels of levoglucosan, while torrefaction pretreatment enhanced the proportion of catechols in the volatile products. Increasing both the temperature and catalyst loading in catalytic pyrolysis promoted the formation of aromatic hydrocarbons. At lower pyrolysis temperatures (450–500 °C), acid-leaching pretreatment resulted in slightly lower proportions of aromatics, while torrefaction pretreatment had the opposite effect. Overall, temperature and catalyst loading were considerably more important factors in catalytic fast pyrolysis of pine wood than biomass pretreatment as studied by Py-GC/MS. [ABSTRACT FROM AUTHOR]

The toxicological research and analysis of synthetic cannabinoids (SCs) have been the focus of scientists. SCs often cause severe acute intoxication after smoking, which may be related to the pyrolysis products formed during the heating process. However, the toxicology studies in vitro and in vivo are hampered by the lack of data on pyrolysis products. Moreover, SCs are diverse and rapidly updated, and the detection of SCs is always a step behind the changes in the illegal market. Here, 44 SCs were analyzed using pyrolysis-gas chromatography/mass spectrometry at 300, 600, and 800 ℃, respectively. The pyrolysis patterns of different SCs under the oxygen-free condition were proposed, based on the pyrolysis products. The shared and characteristic pyrolysis products of 44 SCs were obtained and employed as analytical markers for SCs identification. SCs in one seized e-liquid sample were accurately identified on the basis of the shared and characteristic pyrolysis products. The pyrogram profiles obtained by pyrolyzing SC standards at 600 ℃ were characteristic and reproducible. Therefore, a pyrogram library containing 44 entries for SCs was built through Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine. The pyrogram fingerprinting was used to identify eight unknown SC powders successfully. The results demonstrate the great potential of the pyrolysis pattern of SCs in drug analysis. [Display omitted] • 44 synthetic cannabinoids (SCs) were analyzed using Py-GC/MS. • The pyrolysis patterns of different SCs under the oxygen-free condition were proposed. • Shared and characteristic pyrolysis products are markers for SCs identification. • A pyrogram library containing 44 entries for SCs was established. • The pyrogram fingerprinting was used to identify seized SC powders successfully. [ABSTRACT FROM AUTHOR]

The article presents a study which compared the use of gas chromatography/mass spectrometry (GC/MS) method with React Py-GC/MS method in analyzing the chemical structure of hydrolysis and methanolysis. The variables used include precipitates of the polyamic acid (PAA), tetramethylammonium hydroxide (TMAH) solution, and pyrolyzer. The thermal behavior of polyimides (PI) is described.

Municipal solid wastes (MSW) include a considerable amount of polyvinyl chloride (PVC). How to quickly and harmlessly dispose of the PVC-containing MSW and convert them into a valuable resource is an urgent issue at present. The application of catalysts has yet been proven to be effective in mitigating organic pollutant production. In the present study, a thermogravimetric analyzer (TGA) and pyrolysis-gas chromatography-mass spectrometer (Py-GC/MS) were utilized to investigate the thermodynamic properties, kinetic parameters and pyrolysis characteristics of PVC with different zeolites including HZSM-5 with the Si/Al of 80 and 280, ferrierite, HY and MCM-41 zeolite. It turned out that the introduction of different catalysts with different pore structures and acid site concentrations made different catalytic effects on the cracking mechanism of PVC. Among the five zeolites, MCM-41 decreased temperature at the 50 % conversion to 296 °C, increased weight loss mate at a maximum of 25 %/min and generated fewer PAHs (whose changing amplitude decreased by 94 % in ex-situ catalytic mode in comparison to non-catalytic mode), indicative of its higher catalytic activity in PVC polymer degradation. Under the consideration of maximizing catalytic cracking activity and minimizing secondary pollutants production, non-catalytic dechlorination at approximately 300 °C followed by catalytic degradation in ex-situ mode over mesoporous MCM-41 at higher temperatures was the best recommendation. [Display omitted] • Thermodynamic properties, kinetic parameters and pyrolysis characteristics of PVC were investigated. • The catalytic effects of HZSM-5, HY, ferrierite and MCM-41 were studied. • The catalytic mode had a significant effect on product distribution. • MCM-41 is the most suitable catalyst for the catalytic cracking of sterically challenging PVC polymers. [ABSTRACT FROM AUTHOR]

A method for analysis of Chinese crude propolis was developed by pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) with a vertical microfurnace pyrolyzer. Propolis sample powder about 0.1 mg was pyrolyzed directly at the optimum pyrolytic temperature of 550 °C without any time-consuming pretreatments. 76 compounds were identified on the resulting pyrogram after the pyrolysis of crude propolis, and all the compounds were grouped into 8 categories such as flavonoids, terpenoids, acids, esters, hydrocarbons, phenols and alcohols, aldehydes and ketones, and others. On the basis of peak areas, the relative intensities of 76 peaks were precisely determined with the relative standard deviations (RSDs (%), n = 3) between 1.1 and 14.0%. Furthermore, the compositions of crude propolis samples from different geographical regions in China were analyzed and compared. The contents of 8 categories of compounds in crude propolis samples were different, the predominant categories being flavonoids, esters or hydrocarbons. And also the contents of main bioactivity compounds such as flavonoids and terpenoids were extremely different, and varied largely with 0–54.9% and 0.6–21.6%, respectively. In addition, abundant triterpenoids were identified in Chinese propolis for the first time. It is proved that Py–GC/MS is a simple, rapid and sensitive method for the characterization of the crude propolis. [ABSTRACT FROM AUTHOR]

Fast pyrolysis is a promising technology to promote wood biomass utilization. This thermochemical process produces mainly a liquid bio-oil. Currently, a direct application of bio-oil as fuel is limited due to its poor physicochemical properties. Pressurized Hot Water Treatment (PHWT) has been applied on white spruce and trembling aspen whole wood chips prior to production of pyrolysis oil. The effect of PHWT and the influence of the fast pyrolysis parameters on the bio-oil composition and products distribution were investigated by analytical pyrolysis coupled with gas chromatography/mass spectrometry (Py–GC/MS), it was carried out at two heating rates (100 °C/min and 1000 °C/min) and in temperature ranges from 350 °C to 500 °C for trembling aspen and from 400 °C to 550 °C for white spruce. The pyrolysis products were identified to belong to eleven chemical groups: syringyl derivatives, guaiacyl derivatives, other phenolics, anhydrosugars, low molecular weight acids, fatty acids, furans, pyrans, ketones, aldehydes and alcohols. The results of the analytical pyrolysis indicate that the higher yield is obtained from pretreated than from untreated biomass. The effect of the pretreatment is more important for the 1000 °C/min heating rate than for 100 °C/min. The composition analysis revealed that the higher peak area% of anhydrosugar were obtained from PHWT biomass at 1000 °C/min while the phenols were the major constituents of the pyrolysis products obtained at lower, 100 °C/min heating rate. It is also demonstrated that the acids are still found in pyrolysis products even after pretreatment. The Py–GC/MS results obtained in this study indicate that pretreatment affected the hardwood and softwood in quite different ways. [ABSTRACT FROM AUTHOR]

The painting Ri de Pomme (1988) by American artist Julian Schnabel was recently subjected to an extensive and disputed restoration with polyvinyl acetate (PVAc) paints. To characterize and locate on the painting the materials used in the original and in the repainted areas, we employed several spectroscopic and chromatographic techniques. Fibre Optics Reflectance Spectroscopy (FORS), Micro-Raman, Pyrolysis-Gas Chromatography/Mass Spectrometry (Py- GC/MS) and Gas Chromatography/Mass Spectrometry (GC/MS) were used. The original and restoration paint layers were differentiated by a preliminary FORS survey. The pigments were studied with Micro-Raman and the oil binder was characterized by GC/MS. Moreover, the support of the painting, a weathered tarpaulin, was characterized by Py-GC/MS. [ABSTRACT FROM AUTHOR]

Abstract: In the present study, changes in the chemical structure of the components of deciduous wood species, i.e., birch (Betula spp.), aspen (Populus tremula) and grey alder (Alnus incana) wood, after hydrothermal modification (HTM) were investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and wet chemical analysis. The objective of this study was to elucidate the chemical changes in HTM deciduous wood dependent on the treatment parameters using chemical analysis and analytical pyrolysis and to evaluate the differences between the tree species. The results of both chemical and analytical pyrolysis studies demonstrate the effect of HTM on the chemical composition of deciduous wood. Wet chemical analyses showed that the hemicellulose content in wood decreased considerably (by 60–75%), whereas the cellulose and lignin contents increased by 6–20% and ∼50%, respectively. The thermal destruction of hemicelluloses during HTM was also indicated by the water condensates, which contained acids and sugars. As a result of the HTM, wood transitions from a solid state to an aggregate state, in which the chemical composition of the gases (gas mixture) depends on the chemical composition of the wood. Py-GC/MS can quantitatively and promptly detect changes in the chemical composition of wood after HTM. As a result of the high HTM of wood above 160°C, hemicelluloses are thermochemically destroyed and the primary products are acids (e.g., acetic acid and formic acid). Cellulose and lignin are more thermally stable than the hemicelluloses, as evidenced by the analytical pyrolysis results, which showed that the hemicellulose content in the wood decreased and the lignin content increased by revealing that the acid, ester and ether content in the gases decreased (by 24–33%) and the guaiacyl and syringyl derivative content increased (by 5–7%). Analytical pyrolysis is a promising method for understanding chemical transformations in HTM wood. [Copyright &y& Elsevier]

Comparative analyses of 50 single-layer white architectural paints were conducted to determine the discrimination power using standard techniques and to provide a basis for assessing significance when paints with limited features are not discriminated. Utilizing Fourier transform infrared spectroscopy ( FTIR), 68 undifferentiated pairs resulted, yielding a discrimination of 94.45%. Adding stereomicroscopy, scanning electron microscopy ( SEM) with energy dispersive spectroscopy ( EDS) and backscatter electron ( BSE) imaging, and pyrolysis-gas chromatography/mass spectrometry (Py- GC/ MS), the overall discrimination was 99.35%. The study included blind verification replicates, which resulted in the only pairs without indications of physical or chemical differences. The remaining groups of undifferentiated samples contained subtle differences by at least one technique, but were considered undifferentiated for the discrimination power evaluations. This study demonstrates a high degree of discrimination of single-layer white architectural paints using methods of analysis often encountered in forensic science laboratories. [ABSTRACT FROM AUTHOR]

Malignant melanoma ( melanoma malignum) is one of the most dangerous types of tumor. It is very difficult to cure. In recent years, a lot of attention has been given to chemoprevention. This method uses natural and synthetic compounds to interfere with and inhibit the process of carcinogenesis. In this study, a new treatment strategy was proposed consisting of a combination of 5,7-dimethoxycoumarin (DMC), an activator of melanogenesis, and valproic acid (VPA), a well-known drug that is one of the histone deacetylase inhibitors (HDACis). In conjunction with 1 mM VPA, all of the tested concentrations of DMC (10-150 μM) significantly decreased the proliferation of A-375 cells. VPA and DMC also induced the synthesis of melanin and the formation of dendrite and star-shaped cells. Tyrosinase gene expression and tyrosinase activity significantly increased in response to VPA treatment. Pyrolysis with gas chromatography and mass spectrometry (Py-GC/MS) was used to investigate the structure of the isolated melanin. This showed that the quantitative and qualitative components of melanin degradation products are dependent on the type of applied melanogenesis inductor. Products derived from eumelanin were detected in the pyrolytic profile of melanin isolated from A-375 cells stimulated with DMC. Thermal degradation of melanin isolated from melanoma cells after exposure to VPA or a mixture of VPA and DMC revealed the additional presence of products derived from pheomelanin. [ABSTRACT FROM AUTHOR]

Non-destructive Fourier Transform InfraRed (FTIR) mapping of Eocene aged fossil reptile skin shows that biological control on the distribution of endogenous organic components within fossilized soft tissue can be resolved. Mapped organic functional units within this approximately 50 Myr old specimen from the Green RiverFormation(USA) includeamide and sulphur compounds. These compounds aremost probably derived from the original beta keratin present in the skin because fossil leaf- and other non-skin-derived organic matter from the same geological formation do not show intense amide or thiol absorption bands. Maps and spectra from the fossil are directly comparable to extant reptile skin. Furthermore, infrared results are corroborated by several additional quantitative methods including Synchrotron Rapid Scanning X-Ray Fluorescence (SRS-XRF) and Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS). All results combine to clearly showthat the organic compound inventory of the fossil skin is different fromtheembedding sedimentary matrix and fossil plant material. A new taphonomic model involving ternary complexation between keratin-derived organic molecules, divalent trace metals and silicate surfaces is presented to explain the survival of the observed compounds. X-ray diffraction shows that suitableminerals for complex formation are present. Previously, this study would only have been possible with major destructive sampling. Nondestructive FTIR imaging methods are thus shown to be a valuable tool for understanding the taphonomy of high-fidelity preservation, and furthermore, may provide insight into the biochemistry of extinct organisms. [ABSTRACT FROM AUTHOR]

The backings of 90 black electrical tapes were analyzed to evaluate the chemical components of these films, the ability of individual techniques to discriminate samples, and the ability of the techniques combined to distinguish samples. The techniques utilized and their respective discrimination results were stereomicroscopy and physical measurements, to include observation of surface features of the backing, width, and thickness measurements ( c. 64%); Fourier transform infrared spectroscopy (FTIR) using a microscope accessory ( c. 83%); pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS; c. 81%); and scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS; c. 87%). Ninety-four percent of the backings were discriminated through this combination of analytical methods. Finally, evaluating these results in conjunction with previously published data on the analysis of the adhesives from the same set of electrical tapes provided an overall discrimination of nearly 96%. [ABSTRACT FROM AUTHOR]

Abstract: Polyurethane foams are widely present in museum collections either as part of the artefacts, or as a material for their conservation. Unfortunately many of PU foam artefacts are in poor condition and often exhibit specific conservation issues. Their fast thermal and photochemical degradations have been the aim of previous researches. It is now accepted that hydrolysis predominates for polyester-based polyurethane PU(ES) whereas oxidation is the principal cause of degradation for polyether-based polyurethane PU(ET) variety. Only a few studies have been devoted to volatile organic compounds (VOCs) emitted by polyurethanes and, to our knowledge, none were performed on polyurethane foams by using headspace-solid phase microextraction (HS-SPME). The objective of the work described here is to assess the impact of some environmental factors (humidity, temperature and daylight) on the degradation of PU foams by evaluating their volatile fractions. We investigated morphological changes, polymerized fractions and volatile fractions of (i) one modern produced PU(ES) foam and one modern PU(ET) foam artificially aged in different conditions as well as (ii) four naturally aged foams collected from various daily life objects and selected for the representativeness of their analytical data. Characterization procedure used was based on attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and non-invasive headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry (HS-SPME-GC/MS). In this paper, the formation of alcohol and acid raw products for PU(ES) and glycol derivatives for PU(ET) during natural and artificial ageing is confirmed. These main products can be considered as degradation markers for PU foams. Results show that artificial and natural ageing provide similar analytical results, and confirm that the dominant degradation paths for PU(ES) and for PU(ET) are hydrolysis and photo-oxidation, respectively. Lastly, we highlight that non-invasive HS-SPME-GC/MS analysis allows to distinguish between PU(ES) and PU(ET) at any point of their degradations. [Copyright &y& Elsevier]

Abstract: This study involved the comparative analysis and discrimination of 964 architectural paint samples collected in the United States and Canada. The samples were evaluated to determine the extent to which randomly collected architectural finishes can be discriminated following standard operating protocols for paint analysis. The study also provides a basis for assessing the significance of a result in which a pair or group are undifferentiated. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with both backscatter electron imaging (BSI) and energy dispersive spectroscopy (EDS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). To assess the layer characteristics (e.g., number, color, sequence, thickness), stereomicroscopy was used with FTIR and/or SEM as needed. The use of visual and microscopic evaluations in concert with FTIR resulted in 42 undifferentiated pairs, a discrimination of 99.99%. Adding SEM and Py-GC/MS analysis resulted in further discrimination of 31 pairs, resulting in eleven undiscriminated pairs of samples. At the conclusion of the study, samples that remained undifferentiated proved to originate from the same source. Therefore, no random pairs were indistinguishable at the conclusion of all examinations. [Copyright &y& Elsevier]

We examined chemical changes from leaf tissue to soil organic matter (SOM) to determine the persistence of plant chemistry into soil aggregate fractions. We characterized a slow ( Dicranopteris linearis) and fast-decomposing species ( Cheirodendron trigynum) and surface (O), and subsurface (A-horizon) SOM beneath each species using pyrolysis-gas chromatography/mass spectrometry (py-GC/MS), with and without derivatization. The live tissues of Dicranopteris had greater lignin content whereas Cheirodendron had a greater lipid, N-bearing, and polysaccharide component . Despite this difference in leaf chemistry, SOM chemistry was similar between soil aggregate fractions, but different between horizons. The O-horizon contained primarily lignin and polysaccharide biomarkers whereas the A-horizon contained polysaccharide, aromatic, and N-derived compounds, indicating considerable microbial processing of plant litter. The soils beneath Cheirodendron inherited a greater lipid signal composed of cutin and suberin biomarkers whereas the soils beneath Dicranopteris contained greater aromatic biomarker content, possibly derived from plant lignins. The soils beneath both species were more similar to root polysaccharides, lipids, and lignins than aboveground tissue. This study indicates that although plant-derived OM is processed vigorously, species-specific biomarkers and compound class differences persist into these soils and that differences in plant chemical properties may influence soil development even after considerable reworking of plant litter by microorganisms. [ABSTRACT FROM AUTHOR]

This study involved the comparative analysis and discrimination of 90 electrical tape adhesives. The objectives included the evaluation of the ability of individual techniques to discriminate samples and the assessment of the ability of the techniques combined to distinguish samples. The techniques utilized were stereomicroscopy, Fourier transform infrared spectroscopy (FTIR), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Stereomicroscopy, to assess adhesive colors of black, clear/colorless, and clear adhesives with brown tint, resulted in a discrimination of 53%. FTIR analysis yielded eight distinct groups with a discrimination of 67%. Py-GC/MS analysis resulted in 16 groups with a discrimination of 83%. These analyses confirmed and further subdivided the FTIR groups. SEM/EDS resulted in five separate groups at 17% discrimination, increasing the overall discrimination to above 85%. [ABSTRACT FROM AUTHOR]

Abstract: The chronology of polycyclic driftsand sequences in cultural landscapes has mainly been based on the combination of radiocarbon (14C) dating of intercalated organic horizons and pollen analysis. This approach, however, yields indirect age information for the sediment units. Also, as soils are dynamic systems, the pedogenetical interpretation of the 14C ages is often quite difficult. To improve the results of radiocarbon dating, we applied fractionated 14C dating, sustained by soil micromorphology and pyrolysis-gas chromatography/mass spectrometry. The results indicate the complexity of the sources and decomposition processes of SOM, and, consequently, provide information as to why radiocarbon dates are not always reliable for the geochronology of driftsand deposits. We then performed an optically stimulated luminescence (OSL) dating study of the driftsand beds in the sequence. This approach yields direct sedimentation ages, and allows differentiating the instable (sand drifting) period from the stable (soil formation) period in each individual cycle of the sequence. Post-depositional mixing of the sands, however, may upset the reliability of the OSL chronology. [Copyright &y& Elsevier]

Abstract: Two techniques based on analytical pyrolysis and mass spectrometry, direct exposure-MS (DE-MS) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were used to characterise waterlogged archaeological wood and to study degradation patterns of wood in aqueous environments. The two techniques were applied to samples from the excavation of the Site of the Ancient Ships of Pisa San Rossore in Pisa (Italy), and data were compared to those relative to native sound wood of the same species (pine, elm, beech). Both the methods result valuable in the analysis of ancient wood artefacts, avoiding the long wet-chemical procedures that are commonly used in wood analysis, and allowing us to use a minimal sample size. DE-MS achieves a global mass spectral fingerprint of lignin and polysaccharides pyrolysis compounds in few minutes, and the results have been interpreted with the support of principal component analysis (PCA) of mass spectra. Py-GC/MS permits detailed molecular analysis of pyrolysis compounds and highlights some chemical modifications of lignin in archaeological samples, as demethylation of both guaiacyl and syringyl lignin units. Both the techniques demonstrate consistent loss of polysaccharides in archaeological wood. [Copyright &y& Elsevier]

Abstract: A systematic study on organo-layered silicate intermediates used for preparing in situ polyethylene nanocomposites was performed by pyrolysis–gas chromatography/mass spectrometry and thermogravimetric analysis. The type and composition of the pyrolysis products gave useful information about mechanism of thermal degradation. The combination of pyrolysis and thermal decomposition data allowed us to describe the evolution of the organoclay structure after the reactive pretreatment steps with alkylaluminoxane cocatalyst and zirconocene or bis(imino)pyridine iron precatalyst, respectively. A proof of the formation of heterogeneous organoclay-immobilized catalyst was obtained. [Copyright &y& Elsevier]

Abstract: Various wet chemical and spectroscopic methods used in lignin chemistry as well as pyrolysis-gas chromatography/mass spectrometry were applied to elucidate the structure of pyrolytic lignins (PLs) with the help of previously obtained data on molecular weight distribution and laser desorption ionization-time of flight-mass spectrometry. PL from beech wood (Fagus sylvatica L.) was used as reference and in addition results from elemental analysis of carbon and hydrogen were used as basis for proposing five chemical structures, ranging from a tetramer to an octamer. The oligomers are typically characterized by biphenyl, phenyl coumaran, diphenyl ethers, stilbene and resinol structures. The results were used to speculate the formation of the pyrolytic lignin. It is concluded that pyrolytic lignin emerges as result of both recombination reactions and thermal ejection of intact lignin fragments. [Copyright &y& Elsevier]

Abstract: A new offline-pyrolysis rig has been designed to allow multifunctional experiments for preparative and analytical purposes. The system conditions can be set and monitored, e.g. temperature, its gradients and heat flux. Some special features include (1) high heating rates up to 120°C/s with pyrolysis temperatures up to 850°C at variable pyrolysis times and (2) the selection of different atmospheres during pyrolysis. A complete mass balance of products and reactants (gas, liquids and solids) by gravimetric methods and sequential chromatographic analyses was obtained. The pyrolytic behaviour and the decomposition products of lignin-related compounds were studied under different conditions: heating rates (from 2.6°C/s up to 120°C/s), pyrolysis temperatures at 500°C and 800°C in different atmospheres (N2, H2, and mixtures of N2 and acetylene). Kraft lignin, soda lignin, organosolv lignin, pyrolytic lignin from pine bio-oil, residues from biomass hydrolysis and fermentation were studied. The obtained pyrolysis products were classified into three general groups: coke, liquid phase and gas phase (volatile organic compounds (VOC) and permanent gases). The liquid fraction was analysed by GC–MS/FID. In addition, comprehensive two-dimensional GC was applied to further characterise the liquid fraction. VOCs were semi-quantified by a modified headspace technique using GC–MS/FID analysis. The micro-pyrolysis rig proved to be an efficient and useful device for complex pyrolysis applications. [Copyright &y& Elsevier]

[Display omitted] • A new quantification method for synthetic microfibers was proposed using Py-GC/MS. • Wastewater emitted from textile laundry was filtered using 45 and 26 μm filters. • Synthetic microfibers were selectively extracted by the use of hexafluoroisopropanol. • Quantification curves for PET, nylon-6, and PAN had the good linearity (R2 > 0.994). • Blended textiles emitted the larger amount of microfibers than single textiles. This paper reports a new qualification and quantification method for synthetic microfibers (MFs), polyethylene terephthalate (PET), nylon-6 (N-6), and polyacrylonitrile (PAN), emitted from textiles during the laundering process by applying a sequential process involving the filtration of laundry wastewater, solvent extraction with hexafluoroisopropanol (HFIP), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). After filtering the textile laundry wastewater, selective sampling of synthetic MFs excluding non-target matrices and natural fibers was achieved by extracting the filtered samples with HFIP. MF recovery for HFIP extraction by Py-GC/MS analysis was 91.4 %, 98.5 %, and 98.8 % for PET, N-6, and PAN, respectively. The calibration curves obtained from Py-GC/MS analysis for PET, N-6, and PAN in the weight range between 1 and 50 μg showed good linearity (R2 > 0.994). The detection and quantification limits were lower than 0.2 μg and 0.6 μg for all polymers. The quantification results for the MFs extracted from the textile made from a single filer indicated that PET, N-6, and PAN textile produced 481, 111, and 329 mg of MFs/kg textile, respectively. Compared to the single textile (PET), the blended textiles produced larger amounts of MPs, 961 mg/kg for PET/cotton and 680 mg/kg for PET/wool blended textiles, suggesting the easier formation of MFs from blended textiles during textile laundering. [ABSTRACT FROM AUTHOR]

Abstract: An analytical protocol based on optical microscopy, Fourier transforms infrared spectroscopy (FTIR), analytical pyrolysis in the presence of hexamethyldisilazane followed by gas chromatographic/mass spectrometric analysis (Py-GC/MS) and gas chromatography/mass spectrometry after alkaline hydrolysis, solvent extraction and trimethylsilylation (GC/MS) was used in the chemical characterisation of the original adhesives used to fix monochrome and mosaic glass and stone plaques coming from the Late Roman archaeological site of Antinoopolis (Egypt). FTIR analysis demonstrated the presence of calcite fragments, and Py-GC/MS and GC/MS analyses provided detailed molecular compositions, highlighting the presence of a wide range of compound classes including diterpenoid acids, tricyclic abietanes with a high degree of aromatisation, mid- and long-chain monocarboxylic fatty acids, mono- and di-hydroxy acids, α,ω-dicaboxylic fatty acids, n-alkanols, and n-alkanes. Characteristic biomarkers and their distribution patterns indicated the presence of pine pitch in all the adhesives, which in some cases was admixed with beeswax and brassicaceae seed oil. The results provided new insights into the complex recipes used by artisans in ancient Egypt in the production of adhesives and in the sophisticated manufacture of opus sectile decorations. [Copyright &y& Elsevier]

Abstract: Classification of polysaccharides may be achieved on the basis of the monosaccharidic composition after cleavage of glycosidic bonds. Pyrolysis is a useful method to obtain polysaccharide decomposition and generally pyrolysis products can be identified by the use of gas chromatography/mass spectrometry. This paper describes an on-line silylation pyrolysis approach and compares the efficiency of two derivatization reagents, hexamethyldisilazane (HMDS) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), used alone and in combination with trimethylchlorosilane (TMCS) as a catalyst. Some characteristic trimethylsilyl derivatives of monosaccharides have been identified on the basis of their mass spectra. The detected products include trimethylsilyl derivatives of anhydrosugars, cyclopentenones, furancarboxyaldehydes and, at the best silylating conditions, pertrimethylsilylated monosaccharides. The optimization of the derivatization process is under study, as well as the possibility to extend the use of this approach to unknown polysaccharidic samples, with particular attention to cultural heritage materials. [Copyright &y& Elsevier]

Commercial development of trans-1,4-polyisoprene from Eucommia ulmoides Oliver (EU-rubber) requires specific knowledge on selection of high-rubber-content lines and establishment of agronomic cultivation methods for achieving maximum EU-rubber yield. The development can be facilitated by high-throughput and highly sensitive analytical techniques for EU-rubber extraction and quantification. In this paper, we described an efficient EU-rubber extraction method, and validated that the accuracy was equivalent to that of the conventional Soxhlet extraction method. We also described a highly sensitive quantification method for EU-rubber by Fourier transform infrared spectroscopy (FT-IR) and pyrolysis-gas chromatography/mass spectrometry (PyGC/MS). We successfully applied the extraction/quantification method for study of seasonal changes in EU-rubber content and molecular weight distribution. [Copyright &y& Elsevier]

Abstract: The chemical structure of soil organic matter fractions and its relationship to biological processes remains uncertain. We used pyrolysis-gas chromatography/mass spectrometry to analyze the molecular structure of light and heavy fraction C from soils in the San Juan Mountains, Colorado. The soil samples, each replicated three times, were from two elevations (alpine and low forest) within two geochemically distinct basins (igneous and sedimentary). We also analyzed whether variation in the activity of nine enzymes that mediate soil organic matter turnover and nutrient cycling could explain differences in C structure. We found that, across basins and elevation, light fraction and heavy fraction C had distinct chemistries. The light fraction was characterized by an abundance of plant lignin biomarkers, including phenol, 2-methoxy-4-vinyl-(vinylguaiacol) and phenol, 2-methoxy-(guaiacol); in contrast heavy fraction had very little unaltered lignin but an abundance of polysaccharides, such as furfural, and proteins such as pyrrole. In alpine sites, light fraction was less abundant (4.27 versus 31.79gkg−1) and had a lower C/N ratio (17.25 versus 32.01) than in forests. The alpine sites also had higher activities of phosphatase, β-d-1,4-cellobiosidase, β-1,4-glucosidase, l-leucine aminopeptidase, and β-1,4-xylosidase. Protein abundance in the heavy fraction was correlated with peptidase, β-1,4-glucosidase, and phosphatase activities; in the light fraction, protein abundance was correlated with peptidase, xylosidase, and β-d-1,4-cellobiosidase activities. β-1,4-N-acetyl-glucosaminidase was negatively correlated with polysaccharides in the light and heavy fractions and positively correlated with lignin in the light fraction. However, there were not always significant correlations between enzymes and substrates. We suggest that this is likely because soil organic matter chemistry reflects long-term decomposition processes while enzyme dynamics fluctuate with current conditions or due to the presence of a pool of sorbed enzymes in the heavy fraction. While alpine and forest ecosystem C distribution and enzyme activities varied, substantial depletion of lignin derivatives in the heavy fraction across sites suggest that these compounds do not persist in stable soil C pools. [Copyright &y& Elsevier]

Abstract: The harmless removal of municipal solid waste (MSW) requires the biodegradation of organic matter to decrease the risk of gaseous emissions and leaching of contaminants. We studied the re-circulation of leachates from an aerobic treated MSW in a lysimeter and compared these results with a similar laboratory study using small-scale reactors. The reduction of total organic C and biological and chemical oxygen demands provided clear evidence for the biodegradation of organic matter in MSW after 12 months of leachate re-circulation. Curie-point pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and pyrolysis-field ionization mass spectrometry (Py-FIMS) revealed that the biodegradation was more efficient in the large-scale lysimeter than in the laboratory reactors. Different from the laboratory experiments, carbohydrates and N-containing compounds were decomposed almost completely after 2 months. Furthermore, temperature-resolved Py-FIMS showed that leachate re-circulation led to a higher thermal stability of the residual, non-decomposed organic matter. In summary, the two analytical pyrolysis methods proved that the re-circulation of leachates through MSW promoted organic matter biodegradation and offers an improved aerobic waste treatment technology. [Copyright &y& Elsevier]

Biodegradation of organic matter is required to reduce the potential of municipal solid waste for producing gaseous emissions and leaching contaminants. Therefore, we studied leachates of an aerobic-treated waste from municipal solids and a sewage sludge mixture that were re-circulated to decrease the concentration of biodegradable organic matter in laboratory-scale reactors. After 12 months, the total organic C and biological and chemical oxygen demands were reduced, indicating the biodegradation of organic compounds in the leachates. Curie-point pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and pyrolysis-field ionization mass spectrometry (Py-FIMS) revealed that phenols, alkylaromatic compounds, N-containing compounds and carbohydrates were the predominate compounds in the leachates and solid waste. Leachate re-circulation led to a higher thermal stability of the residual organic matter as indicated by temperature-resolved Py-FIMS. Admixture of sewage sludge to solid waste was less effective in removing organic compounds from the leachates. It resulted in drastic higher and more bio-resistant loads of organic matter in the leachates and revealed increased proportions of alkylaromatic compounds. The biodegradation of organic matter in leachates, re-circulated through municipal solid waste, offers the potential for improved aerobic waste treatments and should be investigated on a larger scale. [ABSTRACT FROM AUTHOR]

Pyrolysis combined with gas chromatography and mass spectrometry (Py-GC/MS) was applied for structural investigations of the human substantia nigra neuromelanin. Using synthetic neuromelanins, we have demonstrated that Py-GC/MS is suitable for identification and differentiation of both eumelanin (dopamine-derived) and pheomelanin (cysteinyldopamine-derived) component of the pigment. Structural information on melanin monomers was inferred from their pyrolytic markers. When the human neuromelanin was subjected to pyrolysis, none of the heterocyclic, sulfur-containing markers of pheomelanin component was detected among the thermal degradation products. We have concluded that nigral pigment isolated from normal brain tissue does not contain benzothiazine-type monomers, and that cysteinyldopamine-originated units may be incorporated into the polymer in uncyclized form. The most abundant pyrolysis product was identified as limonene, which indicates that nigral pigment is tightly associated with an isoprenoid-type compound. Pyrolysis in the presence of the methylating reagent allowed identification of high levels of saturated and monounsaturated straight-chain C14–C18 fatty acid species chemically bound to the pigment macromolecule. [ABSTRACT FROM AUTHOR]