Comparison of comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry and gas chromatography-mass spectrometry for the analysis of tobacco essential oils

A sample of tobacco essential oil was analyzed using gas chromatography-mass spectrometry (GUMS)and comprehensive two-dimensional gas chromatography coupled to a time-of-flight mass spectrometry (GC x GC/TOFMS), respectively. In the GUMS analysis, serially coupled columns were used. By comparing the GUMS results with GC x GC/TOFMS result,,, many more components in the essential oil could be found within the two-dimensional separation space of GC x GC. The quantitative determination of components in the essential oil was performed by GC x GC with flame ionization detection (FID), using a method of multiple internal standards calibration, (c) 2005 Elsevier B.V. All rights reserved.

Quantitative determination of compounds in tobacco essential oils by comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry

A quantitative analysis of the individual compounds in tobacco essential oils is performed by comprehensive two-dimensional gas chromatography (GC x GC) combined with flame ionization detector (FID). A time-of-flight mass spectrometer (TOF/MS) was coupled to GC x GC for the identification of the resolved peaks. The response of a flame ionization detector to different compound classes was calibrated using multiple internal standards. In total, 172 compounds were identified with good match and 61 compounds with high probability value were reliably quantified. For comparative purposes, the essential oil sample was also quantified by one-dimensional gas chromatography-mass spectrometry (GC/MS) with multiple internal standards method. The results showed that there was close agreement between the two analysis methods when the peak purity and match quality in one-dimensional GC/MS are high enough. (c) 2005 Elsevier B.V. All rights reserved.

Micro/Nanomechanical and Tribological Properties of thin Diamond-Like Carbon Coatings

The diamond-like carbon (DLC) films with different thicknesses on 9Crl8 bearing steels were prepared using vacuum magnetic-filtering arc plasma deposition. Vickers indentation. nanoin-dentation and nanoscratch tests were used to characterize the DLC films with a wide range of applied loads. Mechanical and tribological behaviors of these submicron films were investigated and interpreted. The hardnesses of 9Crl8 and DLC, determined by nanoindentation, are approximately 8GPa and 60GPa respectively; their elastic moduli are approximately 25OGPa and 600GPa respectively. The friction coefficients of 9Crl8, DLC. organic coating, determined by nanoscratch, are approximately 0. 35, 0. 20 and 0. 13 respectively. It is demonstrated that nanoindentation and nanoscratch tests can provide more information about the near-surface elastic-plastic deformation, friction and wear properties. The correlation of mechanical properties and scratch resistance of DLC films on 9Crl8 steels can provide an assessment for the load-carrying capacity and wear resistance

紫茎泽兰精油各馏份对4种仓库害虫的杀虫活性

：用紫撬泽兰精油的20℃～150。C，150℃一200℃，20．0℃，230℃．230屯。300℃和300℃以上馏协，分剐以 稚．簦嘴，L的熏蒸浓爰楚理米象、玉采象、簿豆象牵蚕熹象，螬幕表磷凄5争犍静中，娃15。℃～200℃馏傍转荣虫活性 最高，其洗是20℃一150℃和200℃～230气馏份，而300℃以上馏份的杀虫活性靛低。进一步的生测结装表明．150屯一 200℃增傍对米象、玉来氧、绿黛象和善豆象24h的l(葡分莉为15 5li4，17．8124，培．0302和16．2671mg／Lo

Conversion of Soybean oil to Biodiesel Fuel with Immobilized Candida Lipase on Textile Cloth

The characteristic of biodiesel fuel production from transesterification of soybean oil is studied. The reactant solution is the mixture of soybean oil, methanol, and solvent. A new lipase immobilization method, textile cloth immobilization, was developed in this study. Immobilized Candida lipase sp. 99-125 was applied as the enzyme catalyst. The effect of flow rate of reaction liquid, solvents, reaction time, and water content on the biodiesel yield is investigated. Products analysis shows that the main components in biodiesel are methyl sterate, methyl hexadecanoate, methyl oleate, methyl linoleate, and methyl linolenate. The test results indicate that the maximum yield of biodiesel of 92% was obtained at the conditions of hexane being the solvent, water content being 20 wt%, and reaction time being 24 h.

西藏产雪莲花的化学成分研究

本学位论文报道了作为传统藏药材广泛使用的西藏产雪莲花化学成分的研究。论文由五章组成，第一章是三种西藏产雪莲花的化学成分的系统分离纯化和结构鉴定；第二章为西藏产雪莲花化学成分的液-质及串联质谱联用分析；第三章提出了以HPLC和TLC为检测方法的雪莲花药材质量标准草案；第四章给出了对西藏产雪莲花挥发油化学成分的气-质联用分析结果；第五章概述了雪莲花的化学成分及药理研究进展。 第一章包括三个部分。第一部分报道了绵头雪莲花(Saussurea laniceps Hand.-Mazz.)全草乙醇提取物化学成分的分离鉴定。采用正相硅胶柱层析及凝胶柱层析等分离方法，从西藏产绵头雪莲花的乙醇提取物中共分离鉴定出15个化合物。其中11个化合物为首次从该植物中分离得到，当中2个化合物系在凤毛菊属植物中首次发现。第二部分报道了水母雪莲花(Saussurea medusa Maxim.)全草乙醇提取物的化学成分。采用正、反相硅胶柱层析及凝胶柱层析等分离方法，共分离鉴定出15个化合物，其中1个为新化合物，另有4个化合物为首次从该植物中分离得到。新化合物结构通过质谱和一维及二维核磁共振等波谱解析方法及碱水解反应确定为巴豆酰基-高车前苷(M-7)。第三部分报道了三指雪莲花 (Saussurea tridactyla Sch.-Bip. ex Hook. f.)全草乙醇提取物的化学成分。采用正相硅胶柱层析及凝胶柱层析等分离方法，共分离鉴定出7个化合物，其中1个化合物为首次从该植物中分离得到。 第二章也包括三个部分。首先是采用液-质联用(HPLC-DAD-ESI-MSn)分析方法，对7个西藏不同产地的三指雪莲花化学成分进行了分析，通过与标准品的 UV和MS数据比较，共鉴定出14个峰，并对其中8个共有成分进行了定量测定。其次是关于八种西藏产雪莲花化学成分的液-质联用(HPLC-DAD-ESI-MSn)分析，通过与标准品的UV和MS数据比较，共鉴定出15个峰，并对其中8个共有成分进行了定量检测。最后通过对八种西藏产雪莲花主要化学成分的多级串联质谱(ESI-MSn)分析，快速、灵敏地鉴定出10个黄酮和3个香豆素化学成分。 第三章同样包括三个部分。首先是以绵头雪莲花中主要香豆素成分东莨菪素和伞形花内酯为对照品，通过TLC定性检测和HPLC含量测定，草拟出较严谨的药材质量标准。其次是将绵头雪莲花、三指雪莲花和雪兔子作为一个药材看待，草拟了以东莨菪素和伞形花内酯的TLC检测为指标的药材质量标准。最后是针对水母雪莲花，以主要黄酮成分芹菜素-7-O-b-D-葡萄糖苷为对照品作TLC检测，并草拟出该药材的质量标准草案。 第四章报道了西藏产雪莲花挥发油的化学成分分析。采用传统水蒸气蒸馏法分别从八种雪莲花全草中提取挥发油，利用气相色谱-质谱联用技术分别从水母雪莲花、绵头雪莲花、槲叶雪莲花、云状雪兔子、拉萨雪兔子、小果雪兔子、雪兔子和三指雪莲花中分别鉴定出83、83、56、34、21、20、24和20个化学成分，分别占其挥发油总量的70.7%、76.0%、82.2%、55.4%、49.7%、70.4 %、76.2%和 76.7%。 第五章为综述，总结和概括了雪莲花的化学和药理研究进展。 The dissertation reports the investigation of the chemical constituents of the genus Saussurea. Quite a lot of species in this genus are traditional Tibetan medicinal plants, and hence have been widely used in traditional Tibetan medicine. This dissertation consisted of five chapters. The first chapter is on the chemical constituents of three Saussurea plants. The second section is about the analysis of chemical constituents of Saussurea plants using HPLC-MS and ESI-MS/MS. In the third chapter, we proposed quality-control standards for the Genus Saussurea based on TLC (thin layer chromatography) and HPLC. The fourth chapter is about chemical compositions of the essential oil from the whole plant of Saussurea plants. The last chapter reviews the research progress of the Genus Saussurea. The first chapter consists of three parts. The first part is about chemical constituents of ethanol extracts from whole plant of Saussurea laniceps Hand.-Mazz. Fifteen compounds were isolated by column chromatography on normal phase silica gel and Sephadex LH-20. Among them, eleven compounds were isolated from this plant for the first time, and two compounds were isolated from Genus Saussurea for the first time. The second part is about chemical constituents of ethanol extracts from whole plant of Saussurea medusa Maxim. Fifteen compounds were isolated by column chromatography on normal phase, reversed phase silica gel and Sephadex LH-20. Five of them were isolated from this plant for the first time, and there is one new flavonoid glucoside which was identified as 6″-O-crotonoyl-homoplantaginin (M-7) based on the evidence of one- and two-dimensional nuclear magnetic resonance, mass spectrometry analysis, and alkaline hydrolysis reaction. The last part is about chemical constituents of ethanol extracts from whole plant of Saussurea tridactyla Sch.-Bip. ex Hook. f.. Seven compounds were isolated by column chromatography on normal phase silica gel and Sephadex LH-20. There is one compound which was isolated from this plant for the first time. The second chapter consists of three parts. In the first part, we analyzed the chemical constituents of S. tridactyla collected from seven different places in Tibet using HPLC-DAD-ESI-MSn. Fourteen peaks in the HPLC were identified by comparison of UV and MS spectra with those of authentic compounds, among which eight common peaks were quantified. In the second part, we analyzed the chemical constituents of eight Saussurea species using HPLC-DAD-ESI-MSn method. Fifteen peaks in the HPLC were identified by comparison of UV and MS spectra with those of authentic compounds and eight main peaks of them were quantified. In the last part, we analyzed the chemical compounds of the above eight Saussurea plants directly by ESI-MS/MS. Thirteen major compounds, including 10 flavonoids and 3 coumarins were easily rapidly identified. The third chapter consists of three parts. In the first part, we proposed a comparative high quality-control standard for S. laniceps, based on quality detection by TLC and quantity analysis by HPLC using two major compounds (umbelliferone and scopoletin) as standard compounds. In the second part, in viewing S. laniceps, S. tridactyla and S. gossypiphora as the members of one family of medicinal herbs, we suggested a quality-control standard based on the TLC detection of the two major compounds (umbelliferone and scopoletin). In the last part, we proposed a quality-control standard for S. medusa based on the TLC detection of its major component (apigenin 7-O-glucoside). The four chapter analyzed the chemical constituents of essential oil of eight Saussurea species. The essential oils were extracted from the whole plants of these samples with water stream distillation. By GC-MS analysis, we identified eighty-three compounds from S. medusa, eighty-three from S. laniceps, fifty-six from S. quercifolia, thirty-four from S. aster, twenty-one from S. kingii, twenty from S. simpsoniana, twenty-four from S. gossypiphora, and twenty from S. tridactyla respetively, which accounted for 70.7%, 76.0%, 82.2%, 55.4%, 49.7%, 70.4 %, 76.2% and 76.7% of the total essential oil, respectively. The last chapter reviews the research progress of the Genus Saussurea.

双花千里光、川芎及宽叶羌活的化学成分研究

本论文由四章组成。第一、二和三章分别报道了双花千里光、川芎和宽叶羌活的化学成分研究。从三种药用植物中共分离和鉴定了40 个化学成分，其中8个为新化合物。第四章概述了藳本属植物及日本川芎的化学成分研究进展。 第一章包括三个部分。第一部分报道双花千里光（Senecio dianthus Franch.）地上部分乙醇提取物的化学成分。采用正、反相硅胶柱层析等各种分离方法，从中共分离出8 个艾里莫酚型倍半萜内酯，其中5 个是新化合物，并且有1 个为首次发现的连接了含氮原子取代基的艾里莫酚型倍半萜内酯。它们的结构经MS、IR、NMR及X-单晶衍射等解析方法确定为2b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (1)、6b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (2)、2b-angeloyloxy-8b,10b- dihydroxyeremophil-7(11)-en-8a,12-olide (3)、2b-angeloyloxy-8a-hydroxyeremophil-7(11),9(10)-dien-8b,12-olide (4)和8b-amino-10b- hydroxyleremophil-7(11)-en-8a,12-olide (5)。这8 个倍半萜内酯经体外生物活性测试表明均具有通过抑制巨噬细胞增殖抵制破骨细胞增生的活性。第二部分对艾里莫酚型倍半萜内酯的质谱裂解规律进行了初步探讨。第三部分报道双花千里光茎、和叶花的挥发油成分分析。采用传统水蒸气蒸馏法分别提取了双花千里光茎、叶和花的挥发油，用气相色谱－质谱联用（GC-MS）技术分别分离鉴定了其化学成分，从茎、叶和花挥发油中各分离和鉴定出70、80 和73 种化学成分，分别占挥发油总量的91.2％、85.7％及93.4％。 第二章包括两个部分。第一部分报道川芎（Ligusticum chuanxiong Hort.）根茎乙醇提取物的化学成分。通过正、反相硅胶柱层析等分离纯化和MS、NMR及X-单晶衍射等解析方法，共分离鉴定了21 个化合物，结构类型分属于苯酞、二聚苯酞、香豆素和脂肪酸类。其中2 个为结构比较新颖的二聚苯酞类化合物：chuanxiongnolide A (19)和chuanxiongnolide B (20)，化合物19 的结构经X-单晶衍射得到确证。第二部分报道川芎挥发油的化学成分。采用不同的提取方法（溶剂萃取法、水蒸气蒸馏法、CO2 超临界流体萃取法）提取川芎挥发油，同时采集不同产地（四川彭县、四川郫县、云南鹤庆）及不同品质（川芎、奶芎、苓子）的川芎产品，利用GC-MS 技术分离鉴定其挥发油的化学成分，计算各成分的相对含量，并对比分析其中的异同。 第三章报道宽叶羌活（Notopterygium forbesii Boiss.）根茎化学成分的分离纯化和结构鉴定。通过正、反相硅胶柱层析等分离纯化和MS、NMR 等解析方法，共分离鉴定了13 个化合物，结构类型分属于香豆素、二氢异香豆素、甾体和羧酸类。其中1 个新二氢异香豆素类成分鉴定为6-methoxy-hydrangenol (37)。 第四章概述了藳本属植物及日本川芎化学成分的研究进展。 This dissertation consisted of four chapters. The former three chaptersrespectively elaborated the phytochemical investigation of three herbal medicines:Senecio dianthus Franch., Ligusticum chuanxiong Hort. and Notopterygium forbesiiBoiss.. Forty compounds, including eight new ones, were isolated and identified byspectral and chemical evidence. The fourth chapter elaborated the study progress ofchemical constituents of Ligusticum genus and Cnidium offcinale. The first chapter consisted of three parts. The first part is about the chemicalconstituents of ethanol extraction and essential oils from the aerial parts of S. dianthu.Eight eremophilenolides were isolated and identified. Among them, five ones are newcompounds and one of them is a novel eremophilenolide attched with an amino group.The structures of the new compounds were identified as 2b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (1)，6b-angeloyloxy-10b-hydroxyeremophil-7(11)-en-8a,12-olide (2)，2b-angeloyloxy-8b,10b-dihydroxyeremophil-7(11)-en-8a,12-olide (3)，2b-angeloyloxy-8a-hydroxyeremophil-7(11),9(10)-dien-8b,12-olide (4) and8b-amino-10b-hydroxyeremophil-7(11)-en-8a,12-olide (5) by spectral evidence andX-ray crystallography analysis. All the compounds were evaluated for theiranti-osteoclstogenesis activity using a proliferation inhibit assay with microphagecells. The second part elementarily discussed the characteristic fragmentation oferemophilenolides isolated from S. dianthus in ESI-MS.The latter part is about thechemical constituents of essential oil extracted from stems, leaves and flowers of S.dianthus with steam distillation. By the GC-MS analysis, 70, 80 and 73 compoundswere respectively isolated and identified which accounted for more than 91.2％, 85.7％ and 93.4％ of total essential oil. The second chapter, including two parts, is about the the chemical constituents ofethanol extraction and essential oils from rhizomes of L. chuanxion. In the first part, twenty-one compounds were isolated and iedntified. Two ones are novel dimericphthalides and the structures were suggested as chuanxiongnolide A (19) andchuanxiongnolide B (20) by spectral evidence and confirmed by X-raycrystallography analysis. In the second part, the samples were collected from differentextract techniques (solvent extraction, steam distillation and supercriticalfluid extraction), different habitats (Peng and Pi counties, Sichuan province; Heqing,Yunnan province) and different qualities (Chuanxiong, Naixiong and Lingzi). Thechemical constituents of essential oil from L. chuanxiong were analyzed by GC-MS and were compared each other. The third chapter is about the chemical constituents of rhizomas of N. forbesii,which belongs to a endemic genus of China. Thirteen compounds were isolated andidentified. One of them is a new dihydroisocoumarin and the structure was identifiedas 6-methoxy-hydrangenol (37) by spectral evidence. The fourth chapter is a review on study progress of chemical constituents ofLigusticum species and Cnidium offcinale.

Sn-modified Pt/SAPO-11 catalysts for selective hydroisomerization of n-paraffins

The hydroconversion of n-paraffins is a key reaction in hydrodewaxing of lubricating base oil. In this paper, we investigate the performance of Pt/SAPO-11 catalysts for isomerization of n-paraffins by the model compound of n-dodecane. Under this experimental condition, yields of feed isomers as well as cracking products are a function of the total n-dodecane conversion. Primary products are methylundecane while multi-brancheds and cracking products are formed in successive reactions. The result shows that the addition of Sn increases the selectivity for isomerization reaction. The most ideal experimental data for hydroconversion of n-dodecane is that the selectivity of isomerized products gets 90% when conversion of n-dodecane is 90% for the Sn-promoted Pt/SAPO-11 catalyst.