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1.
褐煤超临界流体抽提产物中芳烃的组成特征   总被引:5,自引:2,他引:3  
用柱色谱分离、GC/MS分析云南先锋和金所褐煤甲苯(或二甲苯)超临界流体抽提(SCFE)产物油段分中芳烃馏分的组成结构,鉴定出联苯、联苄型结构及它们的烷基衍生物为主要组成部分,菲、芴、芘、荧蒽、苯并芘等多环缩合芳烃的量较少,有较丰富的芳构化五环萜类,包括从三环至五环芳构化的化合物。这些结果反映了多环芳烃成煤过程中的演变情况,可为煤化学研究提供重要的信息。  相似文献   

2.
超临界流体色谱法分离手性化合物的进展   总被引:13,自引:0,他引:13  
超临界流体色谱(SFC)是一种很有潜力的色谱分离技术,可以弥补高效液相色谱(HPLC)和气相色谱(GC)在手性对蚋物分离方面的不足。本文不但介绍了SFC仪器的结构特点,SFC与手性固定相(CSPs)结合在手性分离领域中的应用和最新进展,还对SFC与其它色谱技术的分离效果进行了评价。文献39篇。  相似文献   

3.
用IR,NMR,HPLC研究煤超临界抽提油F2馏分   总被引:1,自引:0,他引:1  
本文采用IR、NMR、HPLC方法研究了我国峰峰矿瘦煤、焦煤、肥煤三种烟煤超临界抽出物F_2馏分,这一馏分为抽出油已烷可溶物(oil)在硅胶色谱柱上用苯冲洗而得到 ̄[6]。由IR、NMR、HPLC分析结果表明:三种烟煤F_2馏分主要由芳烃化合物组成;以单取代苯和邻位双取代苯为主(包括缩合环体系);芳环上取代基链不长,其中含有相当数量的申基取代的芳烃化合物,像甲苯、甲萘、二甲基萘等等。三种烟煤F_2馏分中都含有较多的双环和三环芳烃,以三环芳烃含量最多。双环芳烃主要是萘系化合物;三环芳烃为蒽、菲类化合物;单环和三环以上芳烃含量较少。  相似文献   

4.
建立了动态和静态接口装置,使其能在线联用超临界色谱确定蒽在超临界二氧化碳中的溶解度及溶解平衡过程。静态接口由2个高压阀组成,动态接口由1个高压阀和1个齿轮泵组成。采用静态法测定蒽在超临界二氧化碳中的溶解度,以考察温度和压力对溶解度的影响。实验结果表明,在40~60℃和10~27.5MPa条件下,自行研制的在线超临界色谱联用体系具有较高的稳定性和较好的重现性,溶解度的相对标准偏差(RSD)为0.4%~2.4%,准确性为95.0%~97.7%。采用Méndez-Santiago Teja(MST)模型公式对实验数值关联计算,确定了蒽的溶解度与二氧化碳密度的准线性函数变化关系,计算数值与实验结果之间的相对平均绝对值偏差(AARD)为3.23和14.68。搭建的接口装置亦能够完成超临界流体技术与常规光谱、质谱分析仪器的在线联用分析,在药物合成与分析、过程分析技术(PAT)等领域具有较好的应用潜力。  相似文献   

5.
蒽、菲和咔唑是焦化产品中经常要测定的组份。过去曾有人用氯化镉加聚乙二醇-20M色谱柱、液晶填充柱、液晶不锈钢毛细管色谱柱分离蒽、菲和咔唑,但分析周期均较长。我们曾用半米长联苯型芳羧酸酯类液晶填充柱分离这一混合物,分析时间仍不够理想。本文采用双-(对正戊氧基苯甲酸)-4,4'-联苯二酚酯液晶的WCOT柱分离蒽、菲和咔唑的混合物得到满意的结果。  相似文献   

6.
建立了山竹果皮中杂氧蒽酮类化合物的快速提取、分离、鉴定方法。以无水乙醇为夹带剂,应用超临界萃取技术对山竹果皮中的杂氧蒽酮类活性化合物进行提取,快速制备色谱装置Isolera One对粗提物进行分离,得到2种杂氧蒽酮化合物,经质谱鉴定其为α-倒捻子素(α-Mangostin)和Gartanin,两者经高效液相色谱检测纯度均不低于90%,并辅以电喷雾多级串联质谱对两种化合物的碎裂规律进行了研究。  相似文献   

7.
把高温液晶双-(对正烷氧基苯甲酸)-对-联苯二酚酯类(烷基为丙基、丁基、戊基、己基、庚基和壬基)作气相色谱固定液分离菲、蒽和咔唑.用半米色谱柱测定各个化合物的相对保留值.实验结果说明端基为丁烷氧基和戊烷氧基的液晶(BPBBB和BPBAmB)最好.在BPBAmB柱上16分钟内可满意地把菲、蒽和咔唑分离开.  相似文献   

8.
用甲基苯基聚硅氧烷改性的氯化镉柱(MPS-CdCl_2)基线分离了蒽、菲异构体。蒽、菲的相对保留值(α_(a/p))和调整保留时间(t’R)随氯化镉含量的提高而增大。MPS-CdCl_2。柱选择性好,柱效稳定。  相似文献   

9.
汪瑗  訾凤兰 《分析化学》1998,26(11):1406-1406
1引 言薄层色谱(TLC)已广泛用于中药成分的分离与分析,但在薄层原位无法获得分离后各化合物的分子结构信息;表面增强拉曼光谱(SERS)可高灵敏度获得单一组分的分子振动光谱,将以上技术联用,可在混合物微量分离的原位获得化合物的分子结构信息,本文用TLC-SERS对洋金花注射液中莨菪烷型生物碱进行了探索。2 实验部分2.1 仪器与试剂FT-Raman910光谱仪(Nicollet公司),Nd:YVO4激光器,激光波长1064nm;三用紫外分析仪(上海分析仪器厂)。硅胶CF254(青岛海洋化工厂);…  相似文献   

10.
四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在THF溶反应合成了标题配合物Me4Si2(C5H4)2LnCl[Ln:3Nd,4Sm,5Gd,6Y]和配合物Me4Si2(C5H5)2Ln(C5H5)(THF)n[LN:1La,n=1;2Pr,n=0]。通过元素分析、HNMR、^13CNMR和MS确证了配合物的结构,在THF溶液中重结晶获得配合物4的单晶,X射线衍证明晶体结构为二聚体。4为单斜晶系,空间  相似文献   

11.
衍生-超临界流体萃取金属离子的技术与进展   总被引:2,自引:0,他引:2  
综述了近年来衍生-超临界流体萃取环境样品和环境模拟样品中金属离子的研究报道,结合作者的研究工作,着重评述了超临界流体萃取不同环境样品、环境模拟样品中金属离子的原理、萃取过程的动力学模型、衍生剂的选择原则、金属螫合物在超临界流体中的溶解度理论、影响萃取效率的因素、金属离子超临界流体萃取应用研究现状与进展等。利用流体与基体改性技术实现了金属离子和金属螯合物的超临界流体萃取,且在萃取体系中加入适量的表面活性剂能显著提高萃取效率。  相似文献   

12.
New strategies for sample introduction in supercritical fluid chromatography are reviewed. Both open tubular and packed column systems are examined as the injection demands of each column type are addressed. In addition to advances made in solvent injection methods, supercritical fluid extraction (SFE) is discussed as a solventless injection technique for supercritical fluid chromatography.  相似文献   

13.
固体溶质在超临界三元系统中的溶解度   总被引:1,自引:0,他引:1  
全灿  李淑芬 《化学进展》2004,16(6):858-862
溶质在超临界流体中的溶解度数据是研究超临界流体技术的基础.本文对纯组分固体溶质有夹带剂存在的超临界流体三元系统中,夹带剂增大溶质溶解度的作用进行了总结,述评了夹带剂增大溶质溶解度的机理和常用的计算模型.此外,针对两种固体混合溶质共存于超临界流体中的三元系统,讨论了混合溶质共存对彼此溶解度的影响及其相关的理论假说和计算模型.  相似文献   

14.
A new analytical technique combining on-line supercritical fluid chromatography with capillary gas chromatography has been developed. The supercritical fluid sample effluent is decompressed through a restrictor directly into a conventional capillary gas chromatographic injection port. This technique allows for not only direct (100%) sample transfer from the supercritical fluid chromatograph to the gas chromatograph but also for selective or multi-step heartcutting of various sample peaks as they elute from the supercritical fluid chromatograph. Heartcut times are determined by monitoring the responses from the flame ionization or ultraviolet absorbance detectors on the supercritical fluid chromatograph. This report describes the operational setup and provides the results of heartcut reproducibility experiments using normal hydrocarbon and aromatic test mixtures. Results from studies where operational parameters were varied, such as GC injector temperature, will also be provided. The potential usefulness of this new technique for selective heartcutting will also be demonstrated using complex hydrocarbon streams.  相似文献   

15.
葛宋  陈民 《高等学校化学学报》2011,32(11):2593-2597
采用分子动力学方法计算了超临界Lennard-Jones( L-J)流体混合物的扩散性质,分析了超临界条件下二元L-J混合流体(Ar-Kr体系)中各组分的白扩散系数及Maxwell-Stefan互扩散系数随组分的变化情况.结果表明,与Darken公式能很好地应用于常规条件下的Ar-Kr体系不同,超临界条件下的Maxwe...  相似文献   

16.
醌类化合物的超临界流体萃取研究进展   总被引:1,自引:0,他引:1  
综述了国内近20年来超临界流体萃取技术应用于醌类化合物分离的研究进展,重点介绍了超临界流体萃取技术在中草药中醌类化合物的分析测定方面的应用,分析了影响醌类成分提取效果的主要因素,优化萃取温度和萃取压力能够改善琨类化合物的分离效果,夹带剂的使用则有效地提高了超临界流体的萃取能力。  相似文献   

17.
The possibilities, advantages, shortcomings, and prospects of using supercritical fluids for separating and extracting metal complexes with organic reagents are considered. The theoretical bases of supercritical fluid chromatography and factors influencing the separation of metal complexes (nature of the organic reagent, solubility of reagents and complexes in a supercritical fluid, type of column, motionless phase, addition of a modifier into the mobile phase, and the test solvent) are discussed. The processes occurring in complexes during chromatography are discussed. The bases of supercritical fluid extraction and factors influencing extraction of metals (nature and solubility in a supercritical fluid of an organic reagent and complexes; concentration and ways of introducing the reagent into the system; addition of the modifier, water, and surfactants; the collector; and the matrix) are considered. The possibilities of methods for determining metals in various objects are shown.  相似文献   

18.
19.
Unusual sorption has been reported in thin polymer films exposed to near-critical CO2. When the supercritical fluid approaches the critical point, the film appears to thicken, but it is not clear whether the film swells or there is an adsorption layer on the film surface. A combination of the gradient theory of inhomogeneous systems and the Sanchez-Lacombe equation of state has been used to investigate this phenomenon. It is shown analytically that surface adsorption on an attractive surface is proportional to the compressibility of the fluid. We have also investigated numerically the sorption of supercritical CO2 on poly(dimethylsiloxane) and polyisobutylene, and supercritical 1,1-difluoroethane on polystyrene. By calculating the Gibbs adsorption and adsorption layer thickness of the supercritical fluids, we found in all cases (different substrates, different supercritical fluids) that maximum adsorption occurs when the supercritical fluid is near its compressibility maximum.  相似文献   

20.
In the work described here the extraction processes of carotenoids and chlorophylls were analysed using two extraction techniques, namely ultrasound-assisted extraction and supercritical fluid extraction, and the results are compared. The solvents used for the ultrasound-assisted extraction were N,N′-dimethylformamide and methanol and for the supercritical fluid extraction, carbon dioxide. The raw material studied was Dunaliella salina, a microalgae characterized by the high levels of carotenoids present in its cellular structure. The results indicate that the supercritical fluid extraction process is comparable to the ultrasound-assisted extraction when methanol is used as solvent. In addition, the supercritical extraction process is more selective for the recovery of carotenoids than the conventional technique since it leads to higher values for the ratio carotenoids/chlorophylls. Finally, the effects of pressure and temperature on the extraction yields of the supercritical fluid extraction process were studied.  相似文献   

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