Pyrolysis-GC-MS

热解 - GC - MS
  • 文章类型: Journal Article
    全氟烷基和多氟烷基物质(PFAS)的独特性能导致其在消费品中的广泛使用,包括滑雪蜡。基于与PFAS相关的风险,并与PFAS法规保持一致,从2021/2022赛季开始,国际滑雪联合会(FIS)在所有FIS赛事中禁止含有“C8碳氟化合物/全氟辛酸酯(PFOA)”的产品,领先的制造商将其配方转向短链PFAS化学。迄今为止,大多数表征滑雪蜡中PFAS的研究都使用有针对性的分析方法测量了一套单独的物质。然而,这些物质占蜡中总氟(TF)的比例尚不清楚。在这项研究中,我们试图通过应用多平台来解决这个问题,氟质量平衡方法共10种市售滑雪蜡产品。通过燃烧离子色谱法(CIC)分析TF,发现不同氟化蜡的浓度为1040-51700μgFg-1。相比之下,通过CIC在甲醇提取物中测定的可萃取有机氟(EOF)(后来通过电感耦合等离子体质谱法和19F-核磁共振波谱法确认)的范围为92至3160μgg-1,仅占3-8.8%总氟(TF)。通过循环离子迁移-质谱(IMS)对提取物进行进一步表征,发现15个PFAS的全氟烷基羧酸浓度高达33μgFg-1,而3个产品超过了PFOA的监管限值(0.025μgg-1)高达100倍。所有PFAS的总和仅占EOF的0.01-1.0%,暗示高比例的身份不明的PFAS,因此,热解气相色谱-质谱法用于提供滑雪蜡产品中存在的不可萃取氟的性质的证据。
    The unique properties of per- and polyfluoroalkyl substances (PFAS) have led to their extensive use in consumer products, including ski wax. Based on the risks associated with PFAS, and to align with PFAS regulations, the international ski federation (FIS) implemented a ban on products containing \"C8 fluorocarbons/perfluorooctanoate (PFOA)\" at all FIS events from the 2021/2022 season, leading manufactures to shift their formulations towards short-chain PFAS chemistries. To date, most studies characterising PFAS in ski waxes have measured a suite of individual substances using targeted analytical approaches. However, the fraction of total fluorine (TF) in the wax accounted for by these substances remains unclear. In this study, we sought to address this question by applying a multi-platform, fluorine mass balance approach to a total of 10 commercially available ski wax products. Analysis of TF by combustion ion chromatography (CIC) revealed concentrations of 1040-51700 μg F g-1 for the different fluorinated waxes. In comparison, extractable organic fluorine (EOF) determined in methanol extracts by CIC (and later confirmed by inductively-coupled plasma-mass spectrometry and 19F- nuclear magnetic resonance spectroscopy) ranged from 92 to 3160 μg g-1, accounting for only 3-8.8 % of total fluorine (TF). Further characterisation of extracts by cyclic ion mobility-mass spectrometry (IMS) revealed 15 individual PFAS with perfluoroalkyl carboxylic acid concentrations up to 33 μg F g-1, and 3 products exceeding the regulatory limit for PFOA (0.025 μg g-1) by a factor of up to 100. The sum of all PFAS accounted for only 0.01-1.0 % of EOF, implying a high percentage of unidentified PFAS, thus, pyrolysis gas chromatography-mass spectrometry was used to provide evidence of the nature of the non-extractable fluorine present in the ski wax products.
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  • 文章类型: Journal Article
    这项研究监测了过程并调查了从不同生物质中获得的堆肥的质量。由名为COMPOSTER的实验室中试工厂堆肥了五种农业食品废物的混合物,旨在优化生物降解,并有效地生产堆肥。复合材料由两个35升近绝热,充气生物反应器,模拟涉及典型的中温-嗜热-中温相序列的工业过程。它持续监测和记录温度,内部压力,和生物量重量,同时控制和量化需氧生物降解产生的氧气消耗和二氧化碳排放。所有堆肥的特征都是它们的主要化学物质,物理,和分子特征,以及它们对尖孢镰刀菌的抑制作用。lycopersici(FOL),在番茄幼苗上测试。优化的生物降解产生了50-60%的成熟堆肥,每公斤干物质的累积耗氧量为282至456gO2,每小时每kg挥发性固体的峰值为2.55gO2,二氧化碳排放量为初始碳含量的22-36%,具有每小时每千克挥发性固体5.89克CO2的峰值。含有更多木质纤维素成分的混合物显示出较高的产率和较低的CO2排放。最初存在的大部分氮保留在最终的堆肥中;确实,由于碳损失,所有混合物均表现出明显的氮浓度增加。堆肥决定了有机物分子结构的深层修饰。13CCPMAS-NMR和离线热化学分解GC-MS分析强调了多糖和肽部分的分解程度,选择性保存脂肪族和芳香族顽固化合物,和最佳的持续羞辱。所有堆肥都是非植物毒性的,除了包括胡椒作物残留物,都富含植物营养的宏观和微量元素,并被证明对控制FOL病具有积极作用。包含81.2%番茄作物废物的堆肥表现出对番茄的最佳生长性能和病原体控制。成熟,无植物毒性,营养丰富,抑制性堆肥代表了可以在农业中成功回收的有前途的副产品,包括高价值应用,导致化肥和农药使用量减少。
    This study monitored the process and investigated the quality of compost obtained from different biomasses. Five blends of agri-food waste were composted by a laboratory pilot plant named COMPOSTER, that is designed to optimize biodegradation, and produce compost efficiently. The COMPOSTER consists of two 35-liter nearly adiabatic, aerated bioreactors that simulate an industrial process involving the typical sequence of mesophilic-thermophilic-mesophilic phases. It continuously monitors and records temperature, internal pressure, and biomass weight, while controlling and quantifying oxygen consumption and carbon dioxide emissions resulting from aerobic biodegradation. All composts were characterized for their main chemical, physical, and molecular features, as well as their suppressiveness against Fusarium oxysporum f.sp. lycopersici (FOL), tested on tomato seedlings. Optimized biodegradation yielded 50-60 % mature compost with a cumulative oxygen consumption ranging from 282 to 456 gO2 per kg of dry matter, with peaks of 2.55 gO2 per kg of volatile solids per hour, and carbon dioxide emissions of 22-36 % of the initial carbon content, with peaks of 5.89 g CO2 per kg of volatile solids per hour. Blends containing more ligno-cellulosic ingredients showed higher yields and lower CO2 emissions. Most of the nitrogen present initially was retained in the final compost; indeed, all mixtures exhibited an apparent nitrogen concentration increase due to carbon loss. Composting determined deep modifications in the molecular structure of the organic matter. 13C CPMAS-NMR and off-line thermochemolysis GC-MS analyses highlighted decomposition degree of polysaccharides and peptidic moieties, selective preservation of aliphatic and aromatic recalcitrant compounds, and optimal ongoing humification. All composts were non-phytotoxic, except for that including pepper crop residues, and all resulted rich in macro- and micro-elements for plant nutrition and proved to be active in controlling FOL disease. Compost comprising 81.2 % tomato crop waste exhibited the best growth performance and pathogen control on tomato. Mature, non-phytotoxic, nutrient-rich, and suppressive composts represent promising by-products that can be successfully recycled in agriculture, including high-value applications, leading to lower use of fertilizers and pesticides.
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  • 文章类型: Journal Article
    微塑料(MPs)污染淡水已在全球范围内确立。虽然MPs的分析主要涉及光谱方法来揭示粒子数,使用光谱学进行质量估计的潜力尚未得到充分利用。因此,有必要加强我们对国会议员质量负荷的理解,并确保各种技术的互补性和可比性,以实现准确的量化。这项研究提出了城市水样的第一个比较结果,使用显微傅里叶变换红外(μ-FTIR)成像和热解-气相色谱-质谱(Py-GC-MS)来识别和量化颗粒数量和质量浓度的MPs。夏季和冬季在阿姆斯特丹运河网络内的11个地点进行了两次采样活动。采用先进的原位减少体积的采样泵从10-300μm的尺寸范围内的地表水中收集MP。分析显示MP浓度在16-107MP/m3范围内,通过μ-FTIR成像估计为2.0-789μg/m3,通过Py-GC-MS估计为8.5-754μg/m3。两种分析技术的结果在MP丰度的总体趋势方面显示出良好的可比性,由于固有的方法间差异,聚合物组成发生变化。与郊区相比,市中心的MP浓度升高。此外,在人类活动较高的地区,发现了MP丰度的季节性差异。
    The contamination of freshwater with microplastics (MPs) has been established globally. While the analysis of MPs has predominantly involved spectroscopic methods for revealing particle numbers, the potential of employing spectroscopy for mass estimation has been underutilized. Consequently, there is a need to enhance our understanding of the mass loads of MPs and ensure the complementarity and comparability of various techniques for accurate quantification. This study presents the first comparative results on urban water samples using micro Fourier-transform infrared (μ-FTIR) imaging and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to identify and quantify MPs in both particle numbers and mass concentration. Two sampling campaigns in summer and winter were conducted at 11 locations within the Amsterdam canal network. An advanced in-situ volume-reducing sampling pump was employed to collect MPs from the surface water within the size fraction of 10-300 μm. The analysis revealed MP concentrations within the range of 16-107 MP/m3, estimated to be 2.0-789 μg/m3 by μ-FTIR imaging and 8.5-754 μg/m3 by Py-GC-MS. The results of the two analysis techniques showed good comparability in terms of the general trends of MP abundances, with variations in polymer compositions due to the inherent inter-methodological differences. Elevated MP concentrations were observed in the city center compared to the suburban areas. In addition, seasonal differences in MP abundances were noted at the locations with high human activity.
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  • 文章类型: Journal Article
    这项研究旨在研究实际条件下的轮胎和道路磨损颗粒(TRWP)排放,以提供一些有价值的见解,以了解它们在环境中的来源和命运。使用全仪表化车辆在五种代表性道路类型上行驶,评估了TRWP排放:城市,环城公路,郊区,郊区高速公路,和农村。记录了多个车辆动态变量,以评估影响这些排放的因素。第一次,排放的颗粒被收集在过滤器上,并通过热解与气相色谱-质谱联用进行分析,以确定轮胎的聚合物含量,具体地定量苯乙烯-丁二烯橡胶(SBR)和丁二烯橡胶(BR)热解标记。从五种道路类型获得的测量结果揭示了SBR+BR排放的相似尺寸分布,在(超)细级分(<0.39µm)中发现最大值。在应用SBR+BR到TRWP转换因子时,(超)细馏分TRWP排放被证明是郊区最高的(64±5µg/km),其次是高速公路,城市,环城公路和乡村路线。EU27的产量代表每年排放的高达480吨TRWP,因此表明一个能够威胁人类健康的广泛浸渍的大气舱。此外,对变量的分析表明,加速度,轮胎约束,恒定的持续驱动因素对TRWP排放有特定的影响。
    This study aims to examine tire and road wear particle (TRWP) emissions under realistic conditions in order to provide some valuable insights into understanding their sources and fate in the environment. TRWP emissions were evaluated with a fully instrumented vehicle driving on five representative road types: urban, ring road, suburban, highway, and rural. Multiple vehicle dynamic variables were recorded to assess the factors influencing these emissions. For the first time, emitted particles were collected on filters and analyzed by means of pyrolysis coupled with gas chromatography-mass spectrometry to determine the polymeric content of tires, in specifically quantifying styrene-butadiene rubber (SBR) and butadiene rubber (BR) pyrolytic markers. The measurements obtained from the five road types revealed similar size distributions for SBR + BR emissions, with maxima found in the (ultra)fine fraction (< 0.39 µm). Upon applying an SBR + BR-to-TRWP conversion factor, (ultra)fine fraction TRWP emissions proved to be the highest for suburban (64 ± 5 µg/km), followed by highway, urban, ring road and rural routes. The output represents up to 480 tons of TRWP per year emitted in the EU27, thus suggesting a widely impregnated atmospheric compartment capable of threatening human health. Furthermore, an analysis of variables revealed that acceleration, tire constraints, and constant sustained driving factors had specific impacts on TRWP emissions.
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  • 文章类型: Journal Article
    木质素,地球上第二丰富的生物聚合物,具有主要的芳香族结构,有潜力成为有价值的化学品和其他生物基化学品的原料。在工业中,木质素主要用作产生热能的燃料,因此未得到充分利用。木质素的价值化需要了解分离的木质素的结构和不同的连接,研究木质素的结构具有重要意义。在这篇文章中,通过FT-IR分析从两种类型的反应器(高压釜反应器和置换反应器)分离的木质素样品,尺寸排阻色谱法,热重分析(TGA),和Py-GC-MS从高压釜反应器中分离出的有机溶剂木质素的平均分子量在较高的浓度下降低,和FT-IR显示游离酚含量随着严重程度的增加而增加。除了分子质量和分子质量分散性,从高压釜反应器分离的木质素和从置换反应器分离的木质素之间只有微小的差异。碳水化合物分析,Py-GC-MS和TGA表明,使用任一反应器系统分离的木质素具有高纯度,这表明有机溶剂木质素是一种很好的增值候选物。
    Lignin, the second most abundant biopolymer on earth and with a predominantly aromatic structure, has the potential to be a raw material for valuable chemicals and other bio-based chemicals. In industry, lignin is underutilized by being used mostly as a fuel for producing thermal energy. Valorization of lignin requires knowledge of the structure and different linkages in the isolated lignin, making the study of structure of lignin important. In this article, lignin samples isolated from two types of reactors (autoclave reactor and displacement reactor) were analyzed by FT-IR, size exclusion chromatography, thermogravimetric analysis (TGA), and Py-GC-MS. The average molecular mass of the organosolv lignins isolated from the autoclave reactor decreased at higher severities, and FT-IR showed an increase in free phenolic content with increasing severity. Except for molecular mass and molecular mass dispersity, there were only minor differences between lignins isolated from the autoclave reactor and lignins isolated from the displacement reactor. Carbohydrate analysis, Py-GC-MS and TGA showed that the lignin isolated using either of the reactor systems is of high purity, suggesting that organosolv lignin is a good candidate for valorization.
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  • 文章类型: Journal Article
    真菌是主要的木质素降解剂和可食用的白色纽扣蘑菇,双孢蘑菇,生活在富含木质纤维素的环境中。先前的研究暗示,当双孢菌在工业环境中定居预堆肥的小麦秸秆基质时,会发生脱木质素,假定有助于随后从(半)纤维素中释放单糖以形成子实体。然而,整个双孢霉菌菌丝体生长的结构变化和木质素的特异性定量仍未解决。为了阐明双孢酵母脱木质素的途径,在整个菌丝生长的六个时间点(15天),收集底物,分馏,并通过定量热解-GC-MS分析,2D-HSQCNMR,和SEC。木质素减少在第6天和第10天之间最高,总共达到42%(w/w)。大量的脱木质素伴随着残余木质素的广泛结构变化,包括增加的丁香基至愈创酰基(S/G)比率,积累的氧化部分,和耗尽完整的单元间键。羟基丙吡咯烷酮和羟基丙丁香酮(HPV/S)亚基积累,这表明β-|O-4醚裂解,并暗示漆酶驱动的木质素分解。我们提供了令人信服的证据,证明双孢菇能够广泛去除木质素,对各种子结构的作用机制和敏感性有了深入的了解,因此,我们有助于了解真菌木质素转化。
    Fungi are main lignin degraders and the edible white button mushroom, Agaricus bisporus, inhabits lignocellulose-rich environments. Previous research hinted at delignification when A. bisporus colonized pre-composted wheat straw-based substrate in an industrial setting, assumed to aid subsequent release of monosaccharides from (hemi-)cellulose to form fruiting bodies. Yet, structural changes and specific quantification of lignin throughout A. bisporus mycelial growth remain largely unresolved. To elucidate A. bisporus routes of delignification, at six timepoints throughout mycelial growth (15 days), substrate was collected, fractionated, and analyzed by quantitative pyrolysis-GC-MS, 2D-HSQC NMR, and SEC. Lignin decrease was highest between day 6 and day 10 and reached in total 42 % (w/w). The substantial delignification was accompanied by extensive structural changes of residual lignin, including increased syringyl to guaiacyl (S/G) ratios, accumulated oxidized moieties, and depleted intact interunit linkages. Hydroxypropiovanillone and hydroxypropiosyringone (HPV/S) subunits accumulated, which are indicative for β-|O-4\' ether cleavage and imply a laccase-driven ligninolysis. We provide compelling evidence that A. bisporus is capable of extensive lignin removal, have obtained insights into mechanisms at play and susceptibilities of various substructures, thus we were contributing to understanding fungal lignin conversion.
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  • 文章类型: Journal Article
    N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA), mixed with the solvent N,N-dimethylformamide (DMF), is used as a derivatizing reagent by the Sample Analysis at Mars (SAM) experiment onboard NASA\'s Curiosity rover and will soon be utilized by the Mars Organic Molecule Analyzer experiment onboard the ESA/Roscosmos Rosalind Franklin rover. The pyrolysis products of MTBSTFA, DMF, and the MTBSTFA/DMF mixtures, obtained at different temperatures, were analyzed. Two different pyrolysis modes were studied, flash pyrolysis and ramp pyrolysis (35°C/min), to evaluate the potential influence of the sample heating speed on the production of products in space chromatographs. The effect of the presence of calcium perchlorate on the pyrolysis products of MTBSTFA/DMF was also studied to ascertain the potential effect of perchlorate species known to be present at the martian surface. The results show that MTBSTFA/DMF derivatization should be applied below 300°C when using flash pyrolysis, as numerous products of MTBSTFA/DMF were formed at high pyrolysis temperatures. However, when an SAM-like ramp pyrolysis was applied, the final pyrolysis temperature did not appear to influence the degradation products of MTBSTFA/DMF. All products of MTBSTFA/DMF pyrolysis are listed in this article, providing a major database of products for the analysis of martian analog samples, meteorites, and the in situ analysis of martian rocks and soils. In addition, the presence of calcium perchlorate does not show any obvious effects on the pyrolysis of MTBSTFA/DMF: Only chloromethane and TBDMS-Cl (chloro-tertbutyldimethylsilane) were detected, whereas chlorobenzene and other chlorine-bearing compounds were not detected. However, other chlorine-bearing compounds were detected after pyrolysis of the Murchison meteorite in the presence of calcium perchlorate. This result reinforces previous suggestions that chloride-bearing compounds could be reaction products of martian samples and perchlorate.
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  • 文章类型: Journal Article
    The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in martian samples. To identify organics, both these instruments utilize pyrolysis-gas chromatography coupled to mass spectrometry, and the thermochemolysis agent tetramethylammonium hydroxide (TMAH) is also used to increase organic volatility. However, the reactivity and efficiency of TMAH thermochemolysis are affected by the presence of calcium perchlorate on the martian surface. In this study, we determined the products of TMAH pyrolysis in the presence and absence of calcium perchlorate at different heating rates (flash pyrolysis and SAM-like ramp pyrolysis with a 35°C·min-1 heating rate). The decomposition mechanism of TMAH pyrolysis in the presence of calcium perchlorate was studied by using stepped pyrolysis. Moreover, the effect of calcium perchlorate (at Mars-relevant concentrations) on the recovery rate of fatty acids with TMAH thermochemolysis was studied. Results demonstrate that flash pyrolysis yields more diversity and greater abundances of TMAH thermochemolysis products than does the SAM-like ramp pyrolysis method. There is no obvious effect of calcium perchlorate on TMAH degradation when the [ClO4-] is lower than 10 weight percent (wt %). Most importantly, the presence of calcium perchlorate does not significantly impact the recovery rate of fatty acids with TMAH thermochemolysis under laboratory conditions, which is promising for the detection of fatty acids via TMAH thermochemolysis with the SAM and MOMA instruments on Mars.
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  • 文章类型: Journal Article
    Identifying inorganic and organic soil contaminants in urban brownfields can give insights into the adverse effects of industrial activities on soil function, ecological health, and environmental quality. Liberty State Park in Jersey City (N.J., USA) once supported a major rail yard that had dock facilities for both cargo and passenger service; a portion remains closed to the public, and a forest developed and spread in this area. The objectives of this study were to: 1) characterize the organic and inorganic compounds in Liberty State Park soils and compare the findings to an uncontaminated reference site (Hutcheson Memorial Forest); and 2) identify differences between the barren low-functioning areas and the forested high-functioning areas of the brownfield. Soil samples were solvent-extracted, fractionated, and analyzed by gas chromatography-mass spectrometry and subjected to loss-on-ignition, pyrolysis-gas chromatography-mass spectrometry, inductively-coupled-plasma mass spectrometry, and optical microscopy analyses. Compared to soil from the reference site, the forested soils in Liberty State Park contained elevated percentages of organic matter (30-45%) and more contaminants, such as fossil-fuel-derived hydrocarbons and coal particles. Microscopy revealed bituminous and anthracite coal, coke, tar/pitch, and ash particles. Barren and low-functioning site 25R had a similar organic contaminant profile but contained a higher metal load than other Liberty State Park sites and also lacked higher plant indicators. These can obscure the signatures of contaminants, and data from adjacent barren and vegetated sites are valuable references for soils studies. A deeper understanding of the chemistry, biochemistry, and ecology of barren soils can be leveraged to prevent land degradation and to restore dysfunctional and phytotoxic soils.
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  • 文章类型: Journal Article
    The end groups in radically polymerized poly(methyl methacrylate) samples with tert-butyl peroxy-2-ethylhexanoate as an aliphatic peroxide initiator and 1-octanethiol as a chain transfer reagent were complementarily characterized by high-resolution matrix assisted laser desorption/ionization (MALDI) spiral time-of-flight mass spectrometry (MS) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The end groups comprised of three types of the initiator fragments and octylthio group originating from the chain transfer agent were confirmed by MALDI-MS measurements. In addition, their quantitative information was obtained by Py-GC-MS. Furthermore, combined with size exclusion chromatographic fractionation, the molar mass dependence of the end groups in the PMMA samples was also examined. It was suggested that the relative content of the octylthio end groups might increase with increase in the molar mass of the fractions. The observed results were interpreted in terms of the polymerization reactions of the PMMA samples.
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