MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Na Wang,An Gu,Guanghua Li,Yong Lei
Boiled tung oil is the commonly used drying oil in Chinese cultural relics, and light radiation, temperature are the important factors leading to its aging. In order to investigate the photo and thermal aging behavior of boiled tung oil and determine the characteristic parameters to evaluate its aging degree, micro-UV/Py-GC/MS system has been applied in the present work to monitor the volatile aging products released by boiled tung oil film, to obtain high aging degree boiled tung oil film in short time and to investigate its composition change in different aging degree. Research results showed that volatile products released by boiled tung oil film during UV irradiation and 60 ℃ were mainly series of aldehydes, ketones, carboxylic acids and hydrocarbons with small molecule. With increase of aging time, the type of volatile products remain unchanged, but their amount gradually decreases until cannot be detected. Pyrolytical products of unaged and aged boiled tung oil is the same, but with the increase of aging degree, relative content of glycerol, dicarboxylic acids and azelaic acid in boiled tung oil film gradually increased, while the relative content of oleic, linoleic and eleostearic acid, as well as the content ratio of mono-carboxylic acids to di-carboxylic acids gradually decreased. Changes of volatile and pyrolytical products during aging process were summarized to evaluate the aging degree of boiled tung oil used in cultural relics. Boiled tung oil used in two lacquerware samples collected from the same carved lacquer panel from Fuwang Ge in the Forbidden City, and two polychrome samples separately collected from the inner and outer eave of Yanxi Tang in the Forbidden City were investigated, the aging degree evaluation results of boiled tung oil in historical samples have further confirm the reliability of summarized parameters. Research results of the present work can provide scientific support for the conservation and restoration of related cultural relics, and also lay a foundation for the in-depth study of the photo and thermal aging mechanism of boiled tung oil.
研究领域:
文物保护
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分析化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Toxics
·
2025
·Vol. 13
·期 6
·452
·
IF 4.1
Shanshan Ji,Wei Wang,Yong Wang,Hexiang Bai,Zhuo Li,Zongli Huo,Kai Luo
The rapid increase in plastic production and consumption has intensified research into human exposure to micro- and nanoplastics (MNPs) and their health effects. This study quantitatively assessed MNP internal exposure levels in non-invasive human samples, focusing on the four most common types of MNPs (≥300 nm): polyethylene terephthalate (PET), polypropylene (PP), low-density polyethylene (LDPE), and polystyrene (PS). Urine samples from 18 volunteers (4 males, 14 females) were analyzed using pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS) with P(E-13C2) as an internal standard. The study developed a straightforward yet effective analytical approach for quantifying MNPs in biological fluids. MNPs were detected in all urine samples, with concentrations ranging from 0.098 to 0.986 μg/mL and an average concentration of 0.268 ± 0.235 μg/mL. LDPE, 0.074 μg/mL (interquartile range: 0.030–0.243 μg/mL), was the most abundant polymer, accounting for 67.72% of the total MNPs, followed by PS at 21.17%, while PP and PET accounted for 7.06% and 4.05%, respectively. The results also suggest that drinking water type may serve as a distinct source of MNPs in urine. This study provides novel evidence on MNP (≥300 nm) internal exposure in humans and the influence of drinking habits, highlighting the application prospects of this method in assessing the potential health risks of MNPs.
研究领域:
环境科学
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分析化学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Yande Cai,Ze Wang,Jianjun Wang,Songgeng Li
The formation of chloride products in the process for pyrolysis of municipal solid wastes (MSW) with key model components was investigated by Py-GC/MS method. HCl and CH 3 Cl are identified as the most abundant chloride products for the individual pyrolysis of polyvinyl chloride (PVC) or corn straw (CS) in the range of 200–600 °C. For the pyrolysis of CS, a higher temperature is more favorable for the generation of HCl than that of CH 3 Cl. In the PVC pyrolytic products, chlorobenzene (Ph-Cl), benzyl chloride (Ph-CH 2 Cl), and 1-(chloroethyl)benzene (Ph-CHClCH 3 ) are also detected but in extremely low amounts. For the co-pyrolysis of PVC/CS, the formation of CH 3 Cl is significantly promoted. The synergistic effect in the PVC/CS co-pyrolysis process is mainly attributed to the reaction between the HCl derived from PVC and the decomposition products of lignin. The products of Ph-Cl and Ph-CH 2 Cl are mainly generated from the cyclization of Cl-containing chain species. CH 3 Cl and Ph-CHClCH 3 are mainly generated from secondary reactions between HCl and other pyrolytic products. No remarkable synergistic effect is observed on the formations of chlorides in the co-pyrolysis of PVC/PP (polypropylene), while the generation of Ph-CHClCH 3 is significantly enhanced in the co-pyrolysis of PVC/PS (polystyrene).
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Longfei Wang,Yuanjun Tang,Guoneng Li,Jun Dong,Yao Fang,Wenwen Guo,Chao Ye
This study systematically investigates the effects of Fe-loading on the pyrolysis behavior of three key biomass components: cellulose , xylan , and lignin . Complementary analytical techniques, thermogravimetric analysis (TGA), thermogravimetry-mass spectrometry (TG-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), were utilized to assess the impact of Fe-loading on: ( i ) pyrolysis characteristics, ( ii ) the combined pyrolysis index ( CPI ), ( iii ) small-molecule gas evolution, and ( iv ) tar product distribution. Results demonstrate that the loading of Fe(NO 3 ) 3 significantly reduced the initial pyrolysis temperatures of cellulose and xylan by ∼140 °C and ∼62 °C, respectively, resulting in 58 % and 37 % decreases in CPI values. Conversely, lignin exhibited a 111 % CPI increase under Fe loading conditions, attributable to accelerated aryl-ether bond cleavage. The presence of Fe enhanced CO 2 evolution while suppressing H 2 O and CO generation in cellulose / xylan conditions. In contrast, it promoted CH 4 , H 2 , CO, and CO 2 evolution during lignin pyrolysis. Py-GC/MS analysis indicated that the presence of Fe drives aromatization through deoxygenation pathways while inhibiting ring-opening depolymerization, consequently shifting tar composition toward higher-carbon-number aromatic hydrocarbons. The findings can serve as a valuable reference for the application and promotion of the high-value valorization of waste biomass.
研究领域:
生物能源
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生物质转化
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热化学
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分析化学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2016
·
IF 4.292
Shiyou Xing,Haoran Yuan,Huhetaoli,Yujie Qi,Pengmei Lv,Zhenhong Yuan,Yong Chen
Characterizing the pyrolysis of inorganic matter-rich biomass is important for the preparation of bio-fuel precursors. Here, thermogravimetric and pyrolysis gas chromatography/mass spectroscopy (Py-GC/MS) were employed to elucidate the specific pyrolysis mechanisms of demineralized wood dust (AWD) impregnated with varying amounts of the inorganic compounds, copper and potassium . During the pyrolysis process, there was a dramatic decomposition of hemicellulose (at 200–320°C) and of cellulose (at 320–420 °C), along with slow lignin degradation. The decomposition of hemicellulose was substantially promoted with an increasing amount of copper. In addition, a decreased amount of aldehydes and phenols was observed, indicating a lower level of cellulose and lignin degradation, which led to more generation of bio-fuel precursors (C 5 –C 16 ). In contrast to copper, potassium substantially promoted the decomposition of cellulose and lignin, but had negligible effect on hemicellulose. In the presence of both copper and potassium, the latter had a more dominant role causing an increased amount of small molecular compounds (C 2 –C 4, i.e., from 10.91% to 22.12%), and decreased amounts of bio-fuel precursors (i.e., from 62.19% to 52.49%). The various decomposition pathways that might be involved in the catalytic pyrolysis of wood using copper and potassium are discussed.
研究领域:
能源与燃料
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2019
·
IF 4.507
Xiaona Lin,Lingshuai Kong,Hongzhen Cai,Qingfa Zhang,Dongmei Bi,Weiming Yi
The effects of the type and content of alkali/alkaline earth metals (AAEMs) on the co-pyrolysis of cellulose/high density polyethylene (HDPE) were studied using TGA and Py-GC/MS. AAEMs showed different effects on the decomposition characteristics of cellulose/HDPE mixtures. During cellulose/HDPE co-pyrolysis, AAEMs present in char could act as a base catalyst, with different catalytic effect on products distribution depending on the types of AAEMs. Na showed stronger catalytic cracking effect to promote alkenes formation compared to the use of K, Ca, and Mg. The comparison of experimental and calculated products distributions of raw cellulose/HDPE confirmed the existence of synergistic effect , which facilitated the cleavage of glycosidic linkages to form anhydrosugars and promoted the scission of HDPE chains to produce hydrocarbons. The effect of potassium on this synergy was also investigated. With increased potassium content, the yields of anhydrosugars and hydrocarbons decreased while the yields of furans and ketones increased, suggesting that potassium inhibited the cleavage of glycosidic bonds and promoted ring-opening reactions. This indicated that addition of potassium inhibited the synergy between cellulose and HDPE.
研究领域:
能源与燃料
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2022
·
IF 11.357
Qingcun Li,Yujian Lai,Peng Li,Xing Liu,Ziwei Yao,Jingfu Liu,Sujuan Yu
Although nanoplastics (NPs) are recognized as emerging anthropogenic particulate pollutants, the occurrence of NPs in the environment is rarely reported, partly due to the lack of sensitive methods for the concentration and detection of NPs. Herein, we present an efficient method for enriching NPs of different compositions and various sizes. Alkylated ferroferric oxide (Fe3O4) particles were prepared as adsorbents for highly efficient capture of NPs in environmental waters, and the formed large Fe3O4–NP agglomerates were separated by membrane filtration. Detection limits of 0.02–0.03 μg/L were obtained for polystyrene (PS) and poly(methyl methacrylate) (PMMA) NPs by detection with pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS). When analyzing real water samples from different sources, it is remarkable that PS NPs were detected in 11 out of 15 samples with concentrations ranging from <0.07 to 0.73 μg/L, while PMMA were not detected. The wide detection of PS NPs in our study confirms the previous speculation that NPs may be ubiquitous in the environmental waters. The accurate quantification of PS NPs in environmental waters make it possible to monitor the pollution status of NPs in aquatic systems and evaluate their potential risks.
研究领域:
环境科学
·
分析化学
·
污染研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2023
·Vol. 148
·期 10
·4211-4221
·
IF 4.4
Dai Shuming,Song Ping,Jiao Ziyue,Cheng Yi,Shang Jingzhao,Leng Xuefei,Wei Zhiyong,Li Yang
A series of bisphenol A-based polyarylates was synthesized by using 2,2-bis (4-hydroxyphenyl) propane (BPA), terephthaloyl dichloride (TPC), and isophthaloyl dichloride (IPC) as raw materials and p-tert-butylphenol as a capping agent through interfacial polymerization to investigate the effect of end group structure on polymer properties. And the polymer films could be obtained by solvent casting method. The successful introduction of p-tert-butylphenol into the backbone adjusted molecular masses and achieved a regulable improvement of the polymer’s thermal properties. The thermal mass loss 5% temperature of the polymers raised above 470 °C, which indicated the thermal properties were broadly in line with that of the commercial product U-100. Besides, the addition of capping agent also improved the light transmission of the polymers and the transmittance reached above 83% at a wavelength of 450 nm. In addition, the thermal degradation mechanism of polyarylate and U-100 was investigated by simultaneous thermal analysis (STA)-IR and Py/GC–MS. It was discovered that PAR decomposed thermally at their end groups and ester groups first, followed by the breakage of their carbon–carbon bonds, which coincided with U-100’s thermal degradation mechanism. The thermal degradation mechanism of bisphenol A-based polyarylates was proposed. Graphical abstract
研究领域:
高分子科学
·
材料科学
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Donghua Li,Feng Shi,Meihua Fu,Yi Lu,Can Liu,Xu Lin,Defa Hou,Hao Sun,Cuiping Luo,Zhifeng Zheng,Yunwu Zheng
To unveil the nitrogen migration and conversion characteristics, catalytic copyrolysis of biomass pseudo components and polyamide (PA) with different blend ratios (1:0, 5:1, 3:1, 1:1, 1:3, 1:5, 0:1) under an ammonia atmosphere was proposed to boost the yield of N-containing compounds (NCCs) and N-rich biochar. The evolution and distribution of NCCs in liquid, gas and biochar were systematically investigated with a combination of TG-MS, Py-GC/MS and EPR. Synergistic effects and possible reaction pathways were also evaluated. Experimental results showed that PA could obviously boost biomass conversion due to increasing the chance of secondary cleavage, and the comprehensive synergistic effect of biomass-derived H* radicals, acid sites of the catalyst and cracking reactions (-C-N and C-C bonds) that reduced the reaction energy barrier and enhanced the NH 3 and HCN yields. NH 3 comes from the amino acids that are released from the amino acid pyrolysis and hydrolysis of HCN on the surface of char, while HCN is from the secondary cracking of primary pyrolysis products. Adding biomass increased CO 2 , CO, CH 4 , C-O and C O emissions from co-pyrolysis. Additionally, significant synergetic effects were observed when Biomass/PA= 3:1, which improved the NCCs and pyridine yields by 78.58% and 48.23%, respectively, under the HZSM-5 catalyst. A lower proportion of PA addition facilitated the Maillard reaction and amide bond cleavage to enhance the NCCs content and suppressed π-conjugated ring structure compound evolution and coke-derived O-containing compound polymerization, while a higher content of PA was favorable for amine and diaza heterocycle compound formation. Moreover, the addition of PA reduced the HHV and N content in biochar, resulting in lower pyrrole-N content and graphitization degree due to secondary cross-polymerization reaction of reaction volatiles, but it enhanced the polarity due to higher oxygen content (14.98%).
研究领域:
能源与燃料
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）