947 resultados para Biochar, pirolisi, Py-GC-MS
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为研究生物活性西洋参多糖的性质 ,采取热水提取乙醇分级沉淀、葡聚糖凝胶分离等手段从西洋参根中分得 4个纯多糖 (PPQI- 1~ 4)。基质辅助激光解吸电离质谱 (MAL DI- MS)测定分子量 ,乙酰化衍生结合GC分析测定糖组成。甲基化结合 GC- MS分析测定糖苷键连接位点。结果表明 ,这 4个多糖化合物都是杂多糖 ,分别由不同比例的阿拉伯糖、半乳糖、葡萄糖、糖醛酸组成 ,糖醛酸含量为 30 %~ 6 0 % ,分子量范围 2~ 7万
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对人参茎叶挥发油的有效成分进行分离纯化 ,利用薄层层析 (TL C)、红外光谱 (IR)、气相色谱 (GC)、气相色谱 -质谱 (GC/MS)联机技术从该挥发油中分离鉴定 6个倍半萜烯类化合物 .
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作者改进了气提法富集水中痕量挥发性有机物装置。研究了实验条件对水中痕量有机物富集的影响,并确定了最佳富集条件。以气提法富集气相色谱/质谱法(GC/MS)测定了水样中痕量挥发性有机物,取得了满意的结果。
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本文利用快原子轰击质谱(FABMS)直接测定山核桃油中未经任何前处理的混合甘油三酸酯,能获得其分子量和碎片结构信息,在GC和GC/MS分析的基础上。根据FABMS测得的分子量可推导出甘油三酸酯的组成和不同甘油三酸酯的含量。FABMS定量结果和GC、GC/MS测定结果及文献值相符。
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The catalyst structure of Ti(OBu)4-AlEt3 at different Al/Ti ratios before and after heat aging has been investigated from the data of UV, GC-MS, ESR and C-13 NMR spectra. The complex compounds formed by HTiEt2 and AlEt2(OBu) exist mainly in the catalyst solution, and no -OBu ligands linking with Ti atoms can be found at an Al/Ti ratio of four before heat aging. Many kinds of catalytic species with different size are formed after heat aging the catalyst at 110-degrees-C for 2 h. Dehydrogenation, accompanied by the valence change from Ti3+ to Ti2+, is observed during the aging process of the catalyst.
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应用色谱—质谱(GC-MS)及裂解色谱-质谱(PGC-MS)测定了乙烯基三甲基硅烷等离子体聚合反应中的气体冷凝物及聚合物,研究推导了等离子体聚合反应历程。单体在气相中被电子撞击,然后扩散到基底,在基底发生链增长和链终止反应。
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用气相色谱(GC)和气相色谱-质谱(GC-MS)分析,证明反-8,反-10-十二碳二烯醇醋酸(B)是大豆食心虫[Leguminivora glycinivorella(Mats.)]性信息素的组分。通过触角电位(EAG)测试,发现反-10-十二碳烯醇醋酸酯(A)、B 和反-7,顺-9-十二碳二烯醇醋酸酯(C)对该虫雄蛾触角有强烈刺激作用。大量田间诱蛾试验表明,由 A 和 B 两化合物组成的性引诱剂,对该虫雄蛾有很高的引诱活性。其中 A 和 B 按5∶2混合,剂量50μg/诱捕盆,单盆每日最多诱捕雄蛾达776头,诱捕雄蛾总数是1头活雌蛾的16.8倍。顺-10-十二碳烯醇醋酸酯(D)和反-10-十四碳烯醇醋酸酯(E)降低 AB 的引诱活性,甘油作为缓释剂,能延长诱芯的有效期,即诱蛾活性。上述结果表明,我国大豆食心虫性信息素不同于日本大豆食心虫性信息素。小面积防治应用试验效果明显。
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本文介绍了GC、GC/MS、HPLC方法在分析松花江水系有机污染物中的应用。GC/MS、HPLC所用水样在现场处理,而TLC、GC样品在实验室处理。冬夏两次取样,共检出152种有机化合物,其中主要有机污染物55种,PAH_3占19%,氯化物占14%,芳烃占13%,其它占54%。
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Lipophilic extracts from 16 species of seaweeds collected along the Qingdao coastline were screened and evaluated for their antioxidant activities (AA) using the beta-carotene-linoleate assay system. The diethyl ether soluble extracts of all selected seaweeds exhibited various degrees of antioxidative efficacy in each screen. The highest antioxidant capacities among the tested samples were observed for Rhodomela confervoides and Symphyocladia latiuscula and were comparable with that of the well-known antioxidant butylated hydroxytoluene and greater than that of propyl gallate. The lipophilic content of all 16 samples and the chemical composition of 4 selected seaweeds, R. confervoides and S. latiuscula, which had higher AA, Laminaria japonica, which had intermediate AA, and Plocamium telfairiae, which had lower AA, were analyzed by gas chromatography and gas chromatography-mass spectrometry, respectively. Fatty acids and alkanes were found. The present data indicated an increase in antioxidative property with increasing content of unsaturated fatty acid. The result of this study suggests that seaweeds can be considered as a potential source for the extraction of lipophilic antioxidants, which might be used as dietary supplements or in production in the food industry. This is the first report on the antioxidant activities of lipophilic extracts from seaweeds.
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An acidic polysaccharide (PY3) was isolated from the hot water extract of the red algae Porphyra yezoensis by successive column chromatographies over DEAE-cellulose and Sephadex G-200. PY3 with an average molecular weight of 1.8x10(5) was demonstrated to be composed of galactose (Gal), 3,6-anhydrogalactose (3,6-AnGal), 6-OSO3-galactose (6-OSO3-Gal) and xylose (Xyl) in an approximate molar ratio of 25 : 15, 10, 1. In view of Smith degradation and methylation and on the basis of spectral evidence including those of IR, GC, GC-MS, and H-1 and C-13 NMR, the most probable repeating unit of PY3 could be proposed as [(1-->3)beta -D-Gal(1 --> 4)alpha -L-3,6-AnGal](3)-[(1 --> 3)beta -D-Gal(1 --> 4)alpha -L-6-OSO3-Gal](2) with a xylose moiety at the C-6 of one of every twenty-five beta -D-Gal residues. To our knowledge, PY3 was shown to be the first porphyran possessing occasional xylose branches.
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孔石莼(Ulva pertusa Kjellm)是一种大型经济海藻,除了可直接食用外在医药方面也有广泛的应用。在古代医书上便记载有多种药用活性,我国民间也流传用孔石莼治疗中暑、水肿和小便不利等病症。本论文比较全面地分析了孔石莼多糖和类脂等主要化学组合,探讨用红外和核磁光谱来解释多糖结构,并首次研究了孔石莼多糖的体外抗肿瘤的体内降血脂活性。为进一步开发孔石莼资源做了部分基础性的工作。通过对提取扎石莼多糖和类脂的方法研究,确定了两种主要组仇的提取方法,得到了多糖样品WPS、APS、DWPS、DAPS和类脂样品。用化学和仪器分析方法对多糖样品进行了水分、灰分、硫酸基含量、总糖含量、特性粘度、元素分析、单糖分析、氨基酸分析、红外和核磁光谱分析等。结果表明:用乙醇脱脂后的脱脂孔石莼水提物(DWPS)得率最高,含硫酸基量和总糖量最高,特性粘度最小;孔石莼水提物(WPS)得率和含硫酸基量次之;孔石莼碱提物(APS)因深解性不好未能按常规方法测定其总糖含量,且未检测出水解硫酸根。孔石莼多糖的单糖要有鼠李糖、葡萄糖、木糖、糖醛酸等,并检测到少量的甘露糖和阿拉伯糖。谷氨酸、天冬西氨酸是多糖样品蛋白质中的主要氨基酸,D-3-OH-半胱氨酸含量亦较高。IR谱图中出现了硫酸基的吸收峰:~H-NMR及~(13)C-NMR谱图中出现了鼠李糖和糖醛酸的特征峰。类脂样品中,非极性类脂与极性类脂的比例约为1:2;GC-MS 分析结果表明,不饱和脂质含量达61.37%,其中多不饱和脂类占44.17%,n-3系列高度不饱和脂类占39.90%。三个多糖样品WPS、DWPS、DAPS进行抗口腔上皮癌(KB)和肝癌(Bel)肿瘤细胞体外实验,结果表明在5μg/ml的剂量时三个样品抑制率均在10%以下,无明显活性表现。以烟酸肌醇为阳性对照药,蒸馏水为空白对照,对孔石莼水提多糖WPS进行了三个剂量的降血脂动物实验。实验结果表明:脂蛋白改善情况有明显的剂量依赖性;中高剂量组可显著降低胆固醇、甘油酸三脂,明显改善脂蛋白胆固醇的含量分布:高剂量样品组(500mg/kg·d~(-1))的药用活笥最高,与相同剂量的阳性对照药烟酸肌醇结果相比,药效理佳。并对孔石莼多糖血脂的机理进行了讨论。
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本论文对两种红树林植物海漆 (Excoecaria agallocha L.) 和海桑(Sonneratia caseolaris L.)的化学成分进行了系统研究。 采用常规的硅胶柱层析、制备薄层层析、凝胶 Sephadex LH-20 柱层析、MCI柱层析、反相硅胶柱层析、半制备型 HPLC 以及重结晶等手段,从海漆 (Excoecaria agalloch L. ) 中分离得到 40 个化合物,从海桑(Sonneratia caseolaris L.)中分离得到 30 个化合物。利用各种现代波谱技术 (IR、UV、ESI-MS、EI-MS、1D-NMR、2D-NMR等) 及其化学物理性质,确定了海漆中 32 个化合物的结构,其中包括 1 个新的三萜天然产物以及 15 个首次从海漆中报道的化合物;确定了海桑中 27 个化合物的结构,其中包括 1 个新化合物和一个首次报道其碳谱数据的化合物。本文为首次报道海桑的化学成分研究。 对海漆和海桑粗提物及分离得到的部分化合物进行了抗肝癌细胞毒活性筛选,化合物S22表现出较强活性,其IC50为2.8 μg/mL;海漆和海桑粗提物及其它部分单体化合物只表现出微弱活性;阳性对照丝裂霉素C的IC50为1.1 μg/mL。 对分离得到的部分样品还进行了抗菌活性测试,各样品在测试浓度下对测试菌均未表现出明显的抗菌活性。 首次研究了海漆挥发性成分及其季节性变化。利用水蒸汽法提取了不同季节海漆的挥发性成分,通过GC-MS鉴定其化学组成,发现脂肪酸、二萜和倍半萜是海漆挥发性成分的主要组成,不同季节的挥发性成分差异较大。
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采用GC-MS法对青海产的胡芦巴油脂类化学成分进行了分析,并以面积归一法测其质量分数。共鉴定出41种化学成分,其中34种为该植物种籽中首次得到。实验中,首先采用三氟化硼-甲醇体系对胡芦巴油进行甲酯化,使酯化更完全,测定效果更好。
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研究细穗香薷(Elsholtzia ianthina)的挥发油成分.采用水蒸气蒸馏法提取,用气相色谱质谱联用技术进行分析,用面积归一法计算出有关的相对含量,鉴定出45个化合物,主要的挥发油化学成分为三环[4.3.1.13,8]十一烷-1-醇,2,3,5,6-四甲基酚,共占挥发油总量的56.29%.
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In order to develop and make good use of Nitraria tangutorum Bobr. in Qinghai-Tibetan Plateau for its ecological and medicinal values, the seed oil was extracted by SFE-CQ2 and the chemical constituents was analyzed by GC/MS. The component relative contents were determined by area nomalization. 28 components were separated from the extracts of SFE-CQj and 12 of them, which accounted for 85.99% were identified. They were(Z, Z)-9, 12-octadecadienoic acid (linoleic acid), bicyclo[ 10. 1. 0] tridec-1-ene, 7-pentadecyne, gamma-sitosterol, gamma-tocopherol, 1, -8,Z-10-hexadecatriene,9,12-octadecadienal, 24-methyl-5-cholestene-3-ol,(Z)-9,17-octadecadienal, stigmastan-3,5-dien, eicosane and so on. Among them, the relative content of (Z, Z)-9,12-octadecadienoic acid is the highest, accounting for 65.85% of the total area. It is concluded that N. tangutorum Bobr. seed oil is a rich source of linoleic acid.