水蒸气蒸馏与乙醇提取茭白成分的GC-MS分析

运用水蒸气蒸馏和乙醇提取两种方法分别提取茭白中的化学成分,气相色谱-质谱联用技术进行分离鉴定,面积归一法进行定量分析。并对两种方法所得结果进行比较,分析其中的差异之处。结果显示,水蒸气蒸馏提取物中共分离出106种组分(占总峰面积的82.07%),其中棕榈酸(16.89%)、己二酸二(2-乙基己)酯(6.39%)、油酸酰胺(5.64%)、亚油酸(3.84%)和油酸(3.64%)为主要组分。乙醇提取物中共分离出89种组分(占总峰面积的91.75%),其中棕榈酸(33.71%)、油酸(11.24%)、2-羟基-1-(羟甲基)棕榈酸乙酯(6.84%)、反油酸乙酯(4.93%)和亚油酸乙酯(3.88%)为主要成分。还鉴定出香兰素、月桂酸、茉莉酸等香味成分,以及花生四烯酸等活性组分。结果表明,茭白中的化学成分十分丰富,两种方法提取的成分及其总量存在一定差异。     

气相色谱/质谱法分析柏树叶挥发油的化学成分

采用水蒸气蒸馏技术提取了3种柏树叶的挥发油,经气相色谱/质谱分析,共分离和鉴定了64种化学成分,其主要成分为萜烯类,其他成分为烷烃类、醇类、酚类和酯类等。其中圆柏树叶中分离鉴定出33种挥发性成分,主要萜类为桧烯(20.99%)和柠檬烯(19.78%);中山柏树叶中分离鉴定出37种挥发性成分,主要为α-蒎烯(10.39%)、桧烯(11.19%)和δ-3-蒈烯(8.88%);龙柏树叶中分离鉴定出37种挥发性成分,主要为柠檬烯(24.56%)和β-月桂烯(8.04%)。分离鉴定出3种柏树叶的共有成分14种。     

固相微萃取-气相色谱-质谱法分析香樟籽挥发性成分

采用固相微萃取-气相色谱-质谱法分离和鉴定香樟籽的挥发性成分,用归一化法测定其相对含量。共分离出76种组分,鉴定出47种化合物,其含量占总挥发性成分的97.4%。主要挥发成分为樟脑(57.89%)、柠檬烯(12.68%)、α-蒎烯(4.42%)、莰烯(2.69%)、香橙烯(2.34%)、伞花烃(2.26%)及β-蒎烯(2.12%)。     

GC-MS法分析康定鼠尾草花挥发油中的化学成分

用水蒸气蒸馏法从康定鼠尾草花中提取挥发油,并用气相色谱/质谱联用技术(GC-MS)对挥发油的化学成分进行分离鉴定,用气相色谱峰面积归一化法确定各组分的相对含量,结果从康定鼠尾草花挥发油中鉴定出89种化合物,占总挥发油量的95%以上,其中主要成分是二苯胺(21.528%)、芳樟醇(9.873%)、2-丙酮基-3-蒈烯(7.533%)、1,3,3-三甲基-2-丁酮-环己二烯(5.088%)。本文通过对康定鼠尾草花挥发油化学成分的研究,为鼠尾草资源的进一步开发利用提供实验依据。     

粗裂地钱化学成分研究

采用硅胶和葡聚糖凝胶LH-20柱色谱对粗裂地钱进行分离纯化,从粗裂地钱95%乙醇提取物的石油醚萃取部分中得到4个化合物,应用光谱法对所得化合物进行了结构鉴定。这4个化合物分别鉴定为β-谷甾醇,17(21)-何伯烯,21,22-二羟基何帕烷,地钱素A。4种化合物均为首次从粗裂地钱中分离得到。     

顶空固相微萃取-气相色谱-质谱法分析莪术的挥发油成分

采用顶空固相微萃取-气相色谱-质谱法分离和鉴定莪术挥发油成分,用归一化测定其相对含量。共分离出64个组分,鉴定出57种化合物,其含量占总挥发油组分峰面积98.02%。主要挥发成分及其含量为β-榄香稀(18.73%)、β-榄烯酮(11.03%)、莪术二酮(8.47%)、γ-榄香稀(6.79%)。     

柽柳实脂肪酸成分的分析

本文研究维药柽柳实中脂肪酸的化学成分。采用石油醚和乙醚两种溶剂提取柽柳实中的脂肪酸,经甲酯化后,使用气质联用技术对脂肪酸的组成及含量进行检测。结果表明,两种方法分别鉴定出18种和17种脂肪酸成分,占提取成分总峰面积的99.33%和89.65%,两者所包含的成分基本一致,但含量有一定的差异。石油醚和乙醚提取物中分别鉴定出棕榈酸(35.61%和32.77%),亚油酸(27.26%和18.76%)和油酸(11.33%和9.15%)等脂肪酸,其中不饱和脂肪酸含量分别占总脂肪酸含量的38.59%和27.91%。维药柽柳实中富含不饱和脂肪酸,具有很好的开发利用价值。     

气相色谱-质谱法测定香椿皮中脂溶性成分

香椿皮样品经乙醇提取后用硅胶柱净化,所得洗脱液中脂溶性成分用气相色谱-质谱法分离和鉴定,用归一化法测定其相对含量。共鉴定出41种化学成分,其含量占总脂溶性成分峰面积的91.99%。主要脂溶性成分及其含量为萜烯类(36.58%)、烷烃类(31.70%)和脂肪酸类(21.95%)。     

蒙药荜茇不同提取物的红外光谱

采用傅里叶变换红外光谱法(FT-IR)并借助于二阶导数谱研究了蒙药荜茇原药材及不同溶剂提取物(采用石油醚,95%乙醇和水)所含化学成分的红外谱图整体变化规律。结果表明:荜茇石油醚提取物的红外光谱图可见羰基的吸收峰(1722 cm~(-1))和亚甲基的吸收峰(2927和2855 cm~(-1))比较强,说明其中所含大量的小分子萜类、脂肪酸(酯)等低极性成分;95%乙醇提取物中可能含有芳酮类化合物及糖苷类化合物。水提取物中主要含鞣质及多糖类成分。FT-IR能够简便、快速地提供蒙药不同提取物中主要化学成分的信息,可对其主体成分进行初步的识别,为制定下一步的提取方案和检测方法提供了方向性参考。     

沙枣花挥发油化学成分的研究

本文用自制的水蒸汽蒸馏－溶剂萃取装置从沙枣花鲜花中提取挥发油，测得其含量为0.1%,用毛细管气相色谱-质谱法对挥发油的化学成分进行了研究,色谱分离出85个组分,质谱鉴定了其中47个组分,主要组分为反式肉桂酸乙酯,占总色谱峰面积的78.88%,IR和NMR为主要成分的鉴定提供了佐证。     

Precipitation of lignin and extractives on kraft pulp: effect on surface chemistry, surface morphology and paper strength

The effect of pH on the formation of precipitates (lignin, extractives and metals) on kraft pulp surfaces was examined by electron spectroscopy for chemical analysis, time-of-flight secondary ion mass spectrometry and atomic force microscopy (AFM). A softwood kraft pulp slurry from an oxygen delignification stage was diluted to 3% consistency with water or an acidic Z filtrate. After heating to 70 °C the pH was lowered from 11 to 2–5, using sulphuric acid. Lignin and extractives precipitated at pH values below 6, and their amounts increased with decreasing pH. Most of the precipitated lignin was found on the pulp surface after sheet forming, whereas the main part of the precipitated extractives could be easily washed away with water. The layer of precipitated lignin was apparently thicker than the layer of extractives. AFM showed the precipitated material as a granular phase. Neither surface morphology nor surface coverage depended on the addition of Z filtrate. The amount of metals ID the pulp and on the pulp surface decreased when pH was lowered to 2. More metals, such as Ca and Mg, were detected ID the pulps as well as on the sheet surfaces when the pulp was diluted with Z filtrate. Strength and bonding properties of the pulp sheets were slightly impaired by the precipitated material. Acidification appears to be the main reason for the precipitation of both lignin and extractives on the pulp surfaces. This should be taken into account when filtrates are recycled ID the bleaching or washing of pulps.     

Ionic Liquid–Liquid Extraction and Supported Liquid Membrane Analysis of Lipophilic Wood Extractives from Dissolving-Grade Pulp

In this study, the extraction of lipophilic wood extractives from dissolving pulp samples using ionic liquid–liquid extraction and a two phase hollow fibre supported liquid membrane was investigated. Ionic liquids are capable of dissolving a range of organic and polymeric compounds and are biodegradable, with a negligible vapour pressure. Pulp samples were dissolved in a suitable amount of molten 1-butyl-3-methylimidazolium chloride to give 5 % cellulose solution. Pure cellulose was regenerated by adding water and filtered off. The ionic liquid-aqueous filtrate was first extracted for lipophilic extractives using liquid–liquid extraction. Then, a two phase hollow fibre supported liquid membrane extraction of lipophilic extractives was performed to extract the derivatized compounds prior to analysis by gas chromatography mass spectrometry. The operational parameters of this sample preparation approach were optimised using sterols and fatty acid methyl esters. The variation of enrichment factors and extraction efficiency with respect to liquid membrane, extraction time, stirring speed and sample pH were observed and used to get the optimal parameters. The approach was used in the analysis of oxygen bleached dissolving pulp samples in which main compounds identified were fatty acids, sterols, fatty alcohols, steroid hydrocarbons and ketones. These compounds were similar to those obtained using molecular solvent extraction method, which indicated the absence of chemical reaction between extractives and ionic liquid used.

     

固相微萃取-气相色谱-质谱技术分析槐花的挥发性成分

用顶空固相微萃取操作,结合气相色谱-质谱联用技术对槐花挥发性成分进行了鉴定,并用面积归一化法测定其相对含量.共鉴定出化合物31种,包括酮、醇、酸、甾醇、酚、醛、酯、烷烃、烯烃及杂环等10类化合物,其中酮类化合物占总色谱馏出峰面积的21.15%;醇类化合物占13.78%;酸类占9.15%.其主要化合物有:1,9,12三氧-4,6-二氨基环十四烷-5-硫酮(20.58%),棕榈酸(9.05%),9,12,15-十八三烯醇(7.05%),(Z,Z)-9,12-十八碳二烯酸(6.85%),β-谷甾醇(6.11%).该技术可以简便快捷准确地进行槐花挥发性成分的分析鉴定.     

Preparative isolation and purification of two amides from Mallotus lianus Croiz by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) was applied to the preparative isolation and purification of two amides from Mallotus lianus Croiz. In a single HSCCC separation, using the two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (5:1:5:1 v/v), 247.5 mg of the enriched crude sample was separated to afford 10.3 mg of N-isobutyl-2E,4E,12Z-octadecatrienamide and 15.7 mg of (7Z,10Z,18Z)tricosa-7,10,18-trienamide, a novel compound, with the purities of 98.0 and 94.6%, respectively. The HSCCC fractions were analyzed by HPLC and chemical structures of the compounds were identified by 1D- and 2D-NMR, ESI-, and GC-MS.     

Flavor analysis by HRGC/FT-IR: Cherimoya (Annona cherimolia,mill.) fruit volatiles

The volatiles of fresh cherimoya (Annona cherimolia, Mill.) fruit pulp were separated by combined high-vacuum distillationliquid/liquid extraction (pentane/dichloromethane 2+1). After preseparation by liquid chromatography on silica gel three fractions (I-III) were obtained by eluting with pentane (I), pentane/diethyl ether (9+1) (II), and diethyl ether (III), and fractions II and III were subjected to HRGC/FT-IR analysis. 26 volatile compounds comprising nearly all the main components (range, 10–300 μg/kg fruit pulp) were identified by this technique for the first time in cherimoya fruit.     

An efficient combination of supercritical fluid extraction and high-speed counter-current chromatography to extract and purify (E)- and (Z)-diastereomers of α-asarone and β-asarone from Acorus tatarinowii Schott

In this study, supercritical fluid extraction (SFE) was used to extract essential oil from Acorus tatarinowii Schott under the pressure of 25 MPa and temperature of 35°C. Two (E)- and (Z)-diastereomers of α-asarone and β-asarone were separated and purified by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.2:1:0.3, v/v). The separation yielded a total of 39 mg of α-asarone and 463 mg of β-asarone from 1.0 g of essential oil in one-step separation with the purity of 98.9 and 99.1%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by EI-MS, (1)H-, and (13)C-NMR.     

Surface Composition and Surface Energetics of Various Eucalypt Pulps

In this paper we report on our study of the surface chemical composition, surface energy and acid-base characteristics of plantation eucalypt pulps obtained using the kraft, neutral sulphite semichemical (NSSC) and cold soda processes. X-ray photoelectron spectroscopy (XPS) was used to quantify the surface coverages of extractives and lignin. Inverse gas chromatography (IGC) was used to analyse the dispersive component and the acid-base characteristics of the pulp samples. The pulp yield and the total lignin and extractives in the pulp increased in the sequences of kraft, NSSC and cold soda. The relative surface concentrations of extractives and lignin on the pulps (expressed in terms of the ratios of the pulp surface coverage to the total content of these materials in the pulp) did not increase in the same sequence. The relative surface concentrations of lignin and extractives on the kraft pulps were found to be distinctively higher than those of the NSSC and cold soda pulps. The dispersive components of the surface energy of all pulps were similar before extraction, but increased by different degrees after extraction, with that of the cold soda pulp showing the lowest degree of increase. The acid-base characteristics of the pulps were evaluated using the method of acceptor and donor constants described by Schultz and Lavielle and the method of work of adhesion described by Lundqvist and Ödberg. A comparison of these methods has been made. The acidity of all pulps was found to increase after extraction. The degree of increase in pulp acidity is negatively correlated with the surface lignin concentration on the pulps. The low relative acidity of the cold soda pulp is probably associated with its high surface lignin coverage. An experimental model was established to test this hypothesis.     

纤维素酶前处理没药挥发油成分的GC/MS分析

采用水蒸汽蒸馏法分别从未处理和纤维素酶前处理的没药中提取挥发油,利用气相色谱-质谱(GC/MS)联用技术对其挥发油成分进行分析。从中分别鉴定出38种和34种化学成分,用峰面积归一法通过数据处理系统得出各化学成分在挥发油中的质量分数,占挥发油总成分的67.95%和70.05%。     

Applications of thin-layer chromatography to process control in the pulp and paper field

A thin-layer chromatographic method for analytical separation and detection of the main component groups in extracts of wood, pulp and paper was designed. The method separates fatty acids from resin acids, which has not been reported in earlier studies. Neutral extractives were separated into sterols, triglycerides and steryl esters. The method proved to be useful for troubleshooting and production control and a number of applications are given.