对川芎超临界CO2提取物化学组分的研究

本文采用超临界CO2流体萃取得到川芎提取物,平均收率为6.86%.利用毛细管柱气相色谱-质谱联用仪对川芎提取物的49种化学成分进行分离和鉴定,并用峰面积归一化法测定各种成分的质量分数,结果表明超临界CO2川芎提取物的主要成分为 3-丁基苯酞、3-丁叉苯酞、邻苯二甲酸二丁酯、棕榈酸、亚油酸、川芎内酯等.     

葫芦巴挥发油成分的GC-MS质谱分析

采用气相色谱-质谱联用技术结合计算机标准谱库检索,对由超临界萃取获得的葫芦巴挥发油化学成分进行鉴定,结合质谱数据库对分离的化合物进行结构鉴定,并通过总离子流色谱图的面积归一化法计算各成分的相对含量。从葫芦巴挥发油中共鉴定出26种化合物,葫芦巴挥发油的化学成分分析结果有助于发现葫芦巴挥发油的特征性成分,为针对性的提取分离挥发油中的化合物提供参考。     

川芎提取物挥发性成分分析及在卷烟中的应用研究

采用超临界流体萃取得到川芎提取物,平均收率为6.86％。利用毛细管气相色谱-质谱联用仪对川芎提取物成分分离并鉴定出47种化学成分.用峰面积归一化法测定各种成分的质量分数,结果表明超临界CO2川芎提取物的主要成分为：3-丁基苯酞、3-丁叉苯酞、棕榈酸、亚油酸、川芎内酯等。卷烟加香实验表明：川芎提取物能有效掩盖卷烟杂气,使烟气柔和、香气细腻,可明显提高卷烟质量。     

超临界CO2萃取傣药紫色姜精油的GC-MS分析

采用超临界CO2的方法萃取紫色姜精油,用气相色谱-质谱联用技术对其化学成分进行分析,并用归一化法确定各化学成分的相对百分含量,研究了傣药紫色姜精油中的化学成分。在萃取温度50℃,萃取压力20MPa;分离温度35℃,分离压力8.5MPa下萃取得到的紫色姜精油含有40种化学成分,其中鉴定37种,占92.5％。了解了超临界提取的紫色姜精油成分的化学组成,为紫色姜的进一步开发利用奠定了基础。     

川芎中挥发性化学成分的研究

用超临界二氧化碳萃取和水蒸汽馏法提取川芎挥发油，并设置不同条件及贮存条件，将样品分成五组，用气相色谱-质谱联用仪对各样品的化学成分进行分离鉴定。共鉴定出45个成分，同时对不同条件的结果进行分析并对两种提取方法进行了比较。     

超临界CO2流体萃取法提取小茴香挥发油化学成分的研究

采用超临界CO2流体萃取法(SFE)从小茴香中提取挥发油。用气相色谱-质谱联用技术对化学成分进行分析,共鉴定了50种成分,占挥发油总成分的81%以上。超临界CO2流体萃取法提取的挥发油能更真实、全面地反映小茴香中的化学成分。     

苦石莲脂溶性成分的GC-MS分析

用石油醚萃取了苦石莲的95%乙醇提取物,通过气相色谱-质谱联用技术(GC-MS)对甲酯化后的萃取物和未甲酯化的萃取物中的化学成分进行分离分析,并用峰面积归一化法计算各成分相对含量.结果表明,共分离鉴定出25种化合物,苦石莲脂溶性成分主要为脂肪酸类、烯醛类、烃类及倍半萜类物质,其中所鉴定成分占总流出峰面积的93.082%...     

超临界CO2流体萃取无花果挥发油化学组份的研究

本文采用超临界CO2 流体萃取无花果挥发油 ,平均出油率为 4 .35 %。利用气相色谱———质谱联用仪对无花果挥发油成分分离和鉴定了 6 1种成分 ,并用面积归一化法测定了各种成分的质量分数。发现与文献水蒸气蒸馏法所得之挥发油组分有相当差别。     

匐枝马尾藻挥发油化学成分的研究

首次采用超临界CO2流体萃取技术(SFE-CO2 Method)萃取匐枝马尾藻挥发油,并用毛细管气相色谱-质谱(CGC-MS)联用技术对萃取的匐枝马尾藻挥发油的化学成分进行了研究.经毛细管气相色谱分离出27个峰,共确认了其中21种成分,占挥发油总量的95.36%.其主要成分是十六烷酸、7-Z-十六碳烯酸、9-E-十八碳...     

云南石梓花挥发性成分分析

对云南石梓花采用甲醇提取后再用重蒸石油醚萃取得到石梓花挥发性成分,利用气相色谱-质谱联用技术首次对其挥发油中的化学成分进行分离和结构鉴定,运用气相色谱面积归一化法确定各个成分的相对百分含量。从云南石梓花挥发性成分中鉴定出37个化合物,其主要成分为长链脂肪酸甲酯。对云南石梓花挥发油进行抗菌活性实验,结果表明挥发油没有抗菌活性。     

In-situ monitoring of the stabilization with hydrogen of free radicals thermally induced from coal using high pressure e.s.r., d.t.a. and p.d.a. equipment

High temperature, high pressure e.s.r. measurements of the hydrogenation reaction of Taiheiyo coal in the presence of catalysts were carried out to understand the stabilization of thermally and/or catalytically induced free radicals. A decrease in free radical concentration with increasing temperature was observed for ZnCl₂ and SnCl₂ · 2H₂O catalysts at 10MPa under hydrogen gas. High pressure modified single-cell d.t.a. and p.d.a. equipment augmented the uniquely designed high temperature, high pressure e.s.r. cell. The hydrogenation reaction was monitored under the same experimental conditions as for e.s.r. From the results of the combination of high temperature, high pressure e.s.r. with high pressure d.t.a. and p.d.a., it was established that H₂ molecules can react efficiently with free radicals from coal molecules created by the presence of ZnCl₂ and SnCl₂ · 2H₂O catalysts.     

Characterisation of separated melamine—formaldehyde adducts (methylolmelamines) and adduct mixtures by h.p.l.c. and by n.m.r. and u.v. spectroscopy

Most of the individual methylolmelamines that occur in melamine–formaldehyde adduct mixtures have been separated by preparative high-performance liquid chromatography (h.p.l.c.) and recovered in amounts sufficient to allow their characterisation by high-field ¹H- and ¹³C-n.m.r. Particular attention has been paid to the chemical shifts of the aromatic azine carbons of the melamine nuclei. These carbon shifts are shown broadly to be in agreement with some values previously published, but additional assignments have been made. It is shown that a satisfactory quantitative analysis of the methylolmelamines in a melamine–formaldehyde adduct mixture can be carried out either by h.p.l.c. or by ¹³C-n.m.r.     

Two-dimensional n.m.r. characterization of cycloaliphatic epoxy resins

The cycloaliphatic epoxy resins were studied by various two-dimensional nuclear magnetic resonance (2D n.m.r.) spectroscopies. The ¹³C n.m.r. spectra of the epoxy resins were assigned by using DEPT and 2D INADEQUATE techniques and the ¹H n.m.r. spectra were assigned by using 2D ¹H---¹H and ¹H---¹³C COSY techniques. Complete characterization of the samples synthesized by the oxidation of cyclohexene derivatives not only revealed the existence of the stereochemical isomers resulting from the structural difference of the oxide rings in the samples but also provided the composition ratio of the isomers.     

Evaluation of a delayed coking process by H and C n.m.r. spectroscopy: 2. Detailed interpretation of liquid n.m.r. spectra

The ¹H and ¹³C nuclear magnetic resonance (n.m.r.) spectra of a delayed coking feedstock and products, presented in a previous paper, are analysed here in detail by matching results from inspection of both nuclei. The conventional spectra of whole samples are used in combination with elemental analysis data, and substantial agreement is obtained. Differences are explored to yield valuable information. Interpretation of some band assignments is modified to account for new results. This approach results in a detailed quantitative estimation of a few key structures that contain the main functional groups that characterize these petroleum fractions.     

E.s.r. spectra of eastern oil shales

E.s.r. spectra of several oil shales from eastern and western USA have been measured at 9 and 25 GHz. The spectra of the western shales were similar to previously reported spectra and consist of a Mn²⁺ signal and a featureless organic signal. The eastern spectra consist of a V⁴⁺ signal and a complex and unusual organic signal consisting of at least four component signals. The organic signal has been characterized in terms of g factor, line-width and saturation characteristics. The effect of oxygen on the signal has also been examined. Electron nuclear double resonance (ENDOR) signals have been obtained from the organic signals of the eastern oil shales.     

An h.p.l.e. and m.s. analysis of distillate fractions of neutral oil from hydrogenated Akabira coal to elucidate chemical structures

Akabira coal-derived neutral oil was separated into 25 narrow boiling range fractions covering 183–423 °C, and subsequently separated into compound class fractions : alkanes, monoaromatics, naphthalene-type diaromatics, fluorene-type diaromatics and tri- and/or tetraaromatics, by high performance liquid chromatography (h.p.l.c.). The compound type analyses of the distillate/h.p.l.c. fractions were performed using electron impact mass spectroscopy (e.i.m.s.) or field ionization mass spectroscopy (f.i.m.s.). Aromatic/hydroaromatic compound types and the alkyl side-chain carbon distribution of the distillate/h.p.l.c. fractions were clarified, based on the separation behaviour of h.p.l.c. and the type analyses according to Z value by m.s. By the distillation/h.p.l.c./m.s. method, coal-derived oil was characterized in terms of the distribution of the numbers of aromatic rings, naphthenic rings and carbons of alkyl groups attached to these rings. The variations in chemical structure in a compound class with distillation temperature are discussed in terms of these chemical structural factors.     

活性染料SEFR值与中性固色工艺研究

根据活性染料染色特征值S．E．F．R．选择适用于中性固色工艺的活性染料，结果表明，S值高和低的活性染料对碱的浓度和温度敏感，对固色率的影响较为杂乱，但在温度为80℃时，这类染料的固色率均达到峰值：染色特征值在50-60范围内的活性染料适用于中性固色、以甲酸钠为中性固色剂对活性染料进行中性固色实验，其固色率均可达到60%左右．各项牢度均达到标准。最佳工艺条件为：甲酸钠：15g／L；尿素：20g／L；双氰胺10g／L，固色温度85℃：浴比：1：20。     

Structural characterization of Saudi Arabian heavy crude oil by n.m.r. spectroscopy

Saudi Arabian heavy crude oil was separated into six fractions, including five distillate fractions (<93, 93–204, 204–260, 260–343 and 343–454 °C) and a >454 °C distillation residue. Each fraction was analysed by ¹H and ¹³C n.m.r. spectroscopy, and combined gained information from these analyses provided reliable average structural parameters. These included estimation of aliphatic and aromatic content, average paraffinic chain length, and estimation of hydrogen, methyl and alkyl bearing aromatic carbons for each of the six fractions. The extent of branching in paraffinic chains and amount of aromatic bridgehead carbons were also calculated.     

13C n.m.r. study of raw materials for carbon black

¹³C n.m.r. spectroscopy has been applied to investigate a number of coal tar and petroleum-derived carbon black feedstocks. Application of the J-modulated spin echo technique is especially rewarding, as this method renders the quaternary carbons directly detectable. Thus the quality of carbon black feedstocks can additionally be gauged on the basis of the contents of quaternary carbons, which is a direct indication of the carbon yield in the carbon black production process.     

E.p.r. studies of outburst-prone anthracite coal

Changes in the macroscopic structure of coal have been observed as an outburst-prone area is approached. Associated with this structural change was an increase in the concentration of paramagnetic centres. Initial results suggested that this increase was not due to variation in maceral content within the coal samples but to the mechano-chemical degradation of the coal as a result of tectonic forces applied over geological time.