利用热裂解-气相色谱质谱联用(pyrolysis gas chromatography mass spectrometry,Py-GC/MS)分析技术测定黑木耳新品种‘农黑2号’黑色素裂解产物组分的种类及含量,为解析黑色素的结构奠定理论基础。本研究通过碱溶酸沉法提取黑色素,并...利用热裂解-气相色谱质谱联用(pyrolysis gas chromatography mass spectrometry,Py-GC/MS)分析技术测定黑木耳新品种‘农黑2号’黑色素裂解产物组分的种类及含量,为解析黑色素的结构奠定理论基础。本研究通过碱溶酸沉法提取黑色素,并用紫外可见吸收光谱、傅立叶红外光谱、有机元素分析鉴定黑色素,采用Py-GC/MS技术分析其热裂解产物。结果表明,‘农黑2号’黑色素的最大吸收峰值在波长220 nm处,傅立叶红外光谱符合典型的黑色素特征;经有机元素分析,C、H、N、O元素的含量分别为43.47%、5.24%、11.71%和39.58%,不含硫元素,为真黑色素;检出的热裂解产物主要有苯类、苯酚类、吲哚类、苯基腈类、烃类、酸类等物质,其中苯、苯酚、吲哚等化合物为真黑色素的裂解产物。综上所述,‘农黑2号’黑色素为真黑色素,其基本骨架为苯环和吲哚,本研究为精准解析黑木耳黑色素结构提供科学依据。展开更多
The humic acid（HA） sample obtained from the alluvial soil was characterized by elemental composition, pyrolysis gas chromatography-mass spectrometry（Py-GC-MS） and solid-state 13C nuclear magnetic resonance （13C ...The humic acid（HA） sample obtained from the alluvial soil was characterized by elemental composition, pyrolysis gas chromatography-mass spectrometry（Py-GC-MS） and solid-state 13C nuclear magnetic resonance （13C NMR） spectroscopy. There is high fat content and a few nitrogen-containing functional groups in HA. Py-GC-MS demonstrates the characterization and structural identification of HA. One long list of identified pyrolysis products was proposed for the construction of conceptual model of HA. Solid-state 13C NMR data indicate there are higher values of alkyl-C, O-alkyl-C and aryl-C in HA. The elemental composition, structural carbon distribution and L3C NMR spectroscopy of simulated HA are consistent with those of experimental HA. HyperChem was used to simulate the three-dimensional molecular structure of the monomer, which was optimized by the molecular mechanics of the optimized potential for liquid simulations（OPLS） force field and molecular dynamics simulation to get the stable and balanced conformation. The deprotonation process study depicts that the degree of ionization of HA gets deeper, while the electronegativity of HA and the energy of van der Waals（vdW） increase. Moreover, the 3D structure of humic acid with -4 charges is the most stable. The deprotonation process is an endothermic process.展开更多
采用裂解气相色谱-质谱联用技术对大庆石化公司裂解气压缩机EC301不同压缩段的垢样进行分析。实验使用了RJ-1型管炉式裂解器,在500℃下对垢样进行裂解,色谱柱为60 m DB-1型毛细管色谱柱,质谱采用电子轰击电离源,电离能70 eV。研究表明,...采用裂解气相色谱-质谱联用技术对大庆石化公司裂解气压缩机EC301不同压缩段的垢样进行分析。实验使用了RJ-1型管炉式裂解器,在500℃下对垢样进行裂解,色谱柱为60 m DB-1型毛细管色谱柱,质谱采用电子轰击电离源,电离能70 eV。研究表明,垢样的形成与环戊二烯密切相关。裂解气相色谱-质谱法可以作为分析该垢样成因的有效手段。展开更多
为了探究短期氮沉降对凋落物和土壤有机质化学组成的影响,以亚热带毛竹林为对象,于2020年7月—2022年1月设置氮沉降增加(施氮量50 kg N·hm^(-2)·a^(-1))处理,利用热裂解气相色谱质谱联用(Py-GC/MS)技术,对毛竹林毛竹叶/根凋...为了探究短期氮沉降对凋落物和土壤有机质化学组成的影响,以亚热带毛竹林为对象,于2020年7月—2022年1月设置氮沉降增加(施氮量50 kg N·hm^(-2)·a^(-1))处理,利用热裂解气相色谱质谱联用(Py-GC/MS)技术,对毛竹林毛竹叶/根凋落物和土壤的有机质化学组分进行了分析。结果表明:与对照相比,短期氮沉降处理土壤有机质中酚类的相对含量显著增加了50.9%,而脂肪酸的相对含量显著减少了26.3%;叶凋落物中烷烯烃和木质素的相对含量显著增加了51.9%和33.5%,酚类和多糖的相对含量显著减少了52.2%和56.3%;根凋落物中多杂环芳香烃的相对含量显著减少了16.6%。土壤有机质中脂肪酸的相对含量与叶凋落物中多糖的相对含量呈显著正相关;土壤有机质中酚类的相对含量与叶凋落物中木质素的相对含量呈显著正相关,与多糖的相对含量呈显著负相关。短期氮沉降对毛竹林毛竹叶/根凋落物和土壤的总有机碳、总氮和碳氮比均无显著影响,但是会显著改变三者的有机质化学组成;另外,短期氮沉降下土壤有机质化学组成的变化受叶凋落物有机质化学组成的影响。展开更多
In this work,molecular structures,dynamic mechanical properties and glass transition temperatures of microbe coagulated natural rubber（NR） samples were analyzed by using pyrolysis gas chromatography-mass spectrometr...In this work,molecular structures,dynamic mechanical properties and glass transition temperatures of microbe coagulated natural rubber（NR） samples were analyzed by using pyrolysis gas chromatography-mass spectrometry（py-GC/MS）,rubber process analyzer（RPA） and dynamic mechanical thermal analysis（DMA）.And the cross-linked network structures and mechanical properties of the corresponding NR vulcanizates were further determined by using nuclear magnetic resonance（NMR） crosslink density spectrometer（XLDS-15） and universal testing machines.The results show that NR raw rubber produced by rapidly coagulated with microorganism exhibits a simple molecular structure composition and good dynamic mechanical properties,and the corresponding NR vulcanizates possess the aggregation structure of high cross-linked density,a high glass transition temperature of-61.5 ℃ and high mechanical properties（tensile strength reaches 25.2 MPa）,as compared with that coagulated with acetic acid.展开更多
文摘利用热裂解-气相色谱质谱联用(pyrolysis gas chromatography mass spectrometry,Py-GC/MS)分析技术测定黑木耳新品种‘农黑2号’黑色素裂解产物组分的种类及含量,为解析黑色素的结构奠定理论基础。本研究通过碱溶酸沉法提取黑色素,并用紫外可见吸收光谱、傅立叶红外光谱、有机元素分析鉴定黑色素,采用Py-GC/MS技术分析其热裂解产物。结果表明,‘农黑2号’黑色素的最大吸收峰值在波长220 nm处,傅立叶红外光谱符合典型的黑色素特征;经有机元素分析,C、H、N、O元素的含量分别为43.47%、5.24%、11.71%和39.58%,不含硫元素,为真黑色素;检出的热裂解产物主要有苯类、苯酚类、吲哚类、苯基腈类、烃类、酸类等物质,其中苯、苯酚、吲哚等化合物为真黑色素的裂解产物。综上所述,‘农黑2号’黑色素为真黑色素,其基本骨架为苯环和吲哚,本研究为精准解析黑木耳黑色素结构提供科学依据。
基金the National Natural Science Foundation of China
文摘The humic acid（HA） sample obtained from the alluvial soil was characterized by elemental composition, pyrolysis gas chromatography-mass spectrometry（Py-GC-MS） and solid-state 13C nuclear magnetic resonance （13C NMR） spectroscopy. There is high fat content and a few nitrogen-containing functional groups in HA. Py-GC-MS demonstrates the characterization and structural identification of HA. One long list of identified pyrolysis products was proposed for the construction of conceptual model of HA. Solid-state 13C NMR data indicate there are higher values of alkyl-C, O-alkyl-C and aryl-C in HA. The elemental composition, structural carbon distribution and L3C NMR spectroscopy of simulated HA are consistent with those of experimental HA. HyperChem was used to simulate the three-dimensional molecular structure of the monomer, which was optimized by the molecular mechanics of the optimized potential for liquid simulations（OPLS） force field and molecular dynamics simulation to get the stable and balanced conformation. The deprotonation process study depicts that the degree of ionization of HA gets deeper, while the electronegativity of HA and the energy of van der Waals（vdW） increase. Moreover, the 3D structure of humic acid with -4 charges is the most stable. The deprotonation process is an endothermic process.
文摘采用裂解气相色谱-质谱联用技术对大庆石化公司裂解气压缩机EC301不同压缩段的垢样进行分析。实验使用了RJ-1型管炉式裂解器,在500℃下对垢样进行裂解,色谱柱为60 m DB-1型毛细管色谱柱,质谱采用电子轰击电离源,电离能70 eV。研究表明,垢样的形成与环戊二烯密切相关。裂解气相色谱-质谱法可以作为分析该垢样成因的有效手段。
文摘为了探究短期氮沉降对凋落物和土壤有机质化学组成的影响,以亚热带毛竹林为对象,于2020年7月—2022年1月设置氮沉降增加(施氮量50 kg N·hm^(-2)·a^(-1))处理,利用热裂解气相色谱质谱联用(Py-GC/MS)技术,对毛竹林毛竹叶/根凋落物和土壤的有机质化学组分进行了分析。结果表明:与对照相比,短期氮沉降处理土壤有机质中酚类的相对含量显著增加了50.9%,而脂肪酸的相对含量显著减少了26.3%;叶凋落物中烷烯烃和木质素的相对含量显著增加了51.9%和33.5%,酚类和多糖的相对含量显著减少了52.2%和56.3%;根凋落物中多杂环芳香烃的相对含量显著减少了16.6%。土壤有机质中脂肪酸的相对含量与叶凋落物中多糖的相对含量呈显著正相关;土壤有机质中酚类的相对含量与叶凋落物中木质素的相对含量呈显著正相关,与多糖的相对含量呈显著负相关。短期氮沉降对毛竹林毛竹叶/根凋落物和土壤的总有机碳、总氮和碳氮比均无显著影响,但是会显著改变三者的有机质化学组成;另外,短期氮沉降下土壤有机质化学组成的变化受叶凋落物有机质化学组成的影响。
基金Special Fund for Agro-scientific Research in the Public Interest Project (nyhyzx07-033-6)Natural Science Foundation of Hainan Province (807047)
文摘In this work,molecular structures,dynamic mechanical properties and glass transition temperatures of microbe coagulated natural rubber（NR） samples were analyzed by using pyrolysis gas chromatography-mass spectrometry（py-GC/MS）,rubber process analyzer（RPA） and dynamic mechanical thermal analysis（DMA）.And the cross-linked network structures and mechanical properties of the corresponding NR vulcanizates were further determined by using nuclear magnetic resonance（NMR） crosslink density spectrometer（XLDS-15） and universal testing machines.The results show that NR raw rubber produced by rapidly coagulated with microorganism exhibits a simple molecular structure composition and good dynamic mechanical properties,and the corresponding NR vulcanizates possess the aggregation structure of high cross-linked density,a high glass transition temperature of-61.5 ℃ and high mechanical properties（tensile strength reaches 25.2 MPa）,as compared with that coagulated with acetic acid.
