首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 500 毫秒
1.
朱育芬  刘倩  谢曼丹 《分析化学》2000,28(6):735-737
报道了一系列有机锡RRP(S)SSn(Cy)3化合物的电喷雾电离质谱(ESI-MS)及碰撞诱导解离质谱(CID-MS),总结了其谱图特征,讨论了其碎裂机理,为该类化合物的鉴定提供了依据。  相似文献   

2.
王瑛  刘兰珍 《分析化学》2000,28(10):1267-1270
聚酯型聚氨酯样品用基体辅助激光裂解离子化质谱(MALDI-TOF/MS)和热裂解色谱质谱(PYGC/MS)方法进行了鉴定,PYGC/MS方法可检出PU的一些组成单元的化学结构,但PYGC/MS中大多数的峰,无法从常规的标准化合物的质谱数据库中检索到,而MALDI-MS方法,可明确测出PU试样各种单元的组合、聚合度及PU长链的序列分布,质量数范围可达2300。  相似文献   

3.
用色谱联用技术分析桂腈和溴代苏合香烯顺反异构体   总被引:1,自引:0,他引:1  
许宏琪  盛龙生  安登魁 《色谱》1995,13(4):272-273
应用气相色谱/红外光谱(GC/FTIR)、核磁共振(NMR)等技术快速分离、鉴定了桂腈和溴代苏合香烯的顺反异构体,解决了气相色谱/质谱(GC/MS)分析时出现的保留行为不同的顺反异构体因为质谱图类似而导致谱库检索鉴别困难的问题。从而,可将保留指数与质谱数据相结合,互补各自在鉴定上的局限性。  相似文献   

4.
聚酯型聚氨酯样品用基体辅助激光裂解离子化质谱(MALDI-TOF/MS)和热裂解色谱质谱(PYGC/MS)方法进行了鉴定,PYGC/MS方法可检出PU的一些组成单元的化学结构,但PYGCIMS中大多数的峰,无法从常规的标准化合物的质谱数据库中检索到,而MALDI-MS方法,可明确测出PU试样各种单元的组合、聚合度及PU长链的序列分布,质量数范围可达2300.  相似文献   

5.
从邻苯二胺产品中分离出一种白色针状未知化合物,用液相色谱(HPLC)和气相色谱(GC)鉴定其纯度后,同时进行元素、红外光谱(IR)、紫外光谱(UV)、质谱(MS)、核磁共振(NMR)氢谱及碳谱分析。根据分析的结果进行解析,最后确定未知针状不纯物中其主成分为2,1,3-苯并硫咪唑或2,1,3-硫二氮杂茚(C6H4N2S)(2,1,3-benzoth-iadiazole)。  相似文献   

6.
采用乙醇和丙酮溶剂抽提、CO2超临界萃取(SFE)以及水蒸气蒸馏(SD)的方法提取古蓬香脂乳胶。对乙醇和丙酮提取物进行了HPLC和GC-MS分析。两个提取物的HPLC谱图十分相似,总共可分离出17个组分。而乙醇提取物的GC-MS分析鉴定表明有21个组分。SFE提取物的GC-MS分析得到8个组分。SD提取物有14个组分。在超临界流体中加入甲醇无论对提取物的组分数还是对其浓度都没有什么影响。  相似文献   

7.
鸽子粪挥发性成分的毛细管气相色谱分析   总被引:2,自引:0,他引:2  
利用同时蒸馏萃取法(SDE)提取了有治疗痔疮效果的鸽子粪中的挥发性成分。用毛细管GC/MS/DS联用法分离鉴定了47种组分,占总峰面积的71.59%,再用保留指数和标样进一步确证了其中39种化合物,占总峰面积的57.15%,其中含量较高的组分是十六碳酸(9.03%)、乙酸乙酯(6.85%)、乙醇(4.03%)、1-乙氧基-2-甲基丙烷(3.87%)。从化合物的种类看,主要为醇类(4个)、醛类(11个)、酮类(4个)、酸类(8个)、酯类(5个)和酚类(2个),它们共占总峰面积的43.68%。  相似文献   

8.
疏水条件下甾体化合物的分离及环糊精的作用   总被引:2,自引:0,他引:2  
分别应用胶束电动毛细管色谱法(MECC)、反相色谱法和串联柱HPLC法分离 左旋十八甲基炔诺酮(LNG)、睾酮(T)、孕酮(P-雌二醇(E2)等甾体化合物MECC分离在未涂层毛细管柱上进行。当电泳缓冲溶液为含20mmol/L的2,6-二甲基-β环糊精((DM-β-CD)添加剂和50mmol/L的十二烷基硫酸钠(SDS)的10mmo/L四硼酸钠(PH9.2)时,可实现快速分离。通过与反相色谱法和串联  相似文献   

9.
刘晨光 《催化学报》1999,20(5):504-509
研究了水/甲苯乳化液中二苯并噻吩在分散型钼酸,磷钼酸和四硫钼酸铵催化剂下的加氢脱硫反应。反应在高压釜中于340℃及三种不同的气氛即H2,H2/H2O和CO/H2O(COH和H2O经水煤气转换反应(WGSR)产生原位氢)的存在下进行。用GC和GC-MS鉴定,分析了气体和液体产物的组成。  相似文献   

10.
人参挥发油的提取和分析   总被引:7,自引:0,他引:7  
应用GC-MS-DS联机分析人参挥发油是当前较好的方法,但人参挥发油的提取方法和GC-MS条件的选择明显影响人参挥发油这一复杂天然混合物的分离和鉴定。本工作严格控制提取条件,提高了挥发油收率,达0.95%;选择最佳GC-MS条件,鉴定出76种化合物,该法稳定重现性好。  相似文献   

11.
谢园园  花磊  陈平  侯可勇  蒋吉春  王艳  李海洋 《色谱》2015,33(2):188-194
建立了一种气相色谱(GC)与单光子电离-飞行时间质谱(SPI-TOF MS)联用(GC/SPI-TOF MS)的分析方法。首先,设计了一种双层套管的传输管用于连接GC与SPI-TOF MS,实现了GC与单光子电离离子源的无缝连接。在此基础上,以n-十五烷标准品和苯/甲苯/二甲苯的标准气为对象,对电离源的重要电压参数进行了优化,得到了纯净的分子离子峰,实现了对各类有机物的快速和准确定性。最后,将该方法用于分析柴油中的挥发性与半挥发性有机物,获得了柴油组分的二维GC×SPI-TOF MS谱图。不需要复杂的谱图解析和数据处理,根据谱图中离子的质荷比(m/z)归纳了柴油的主要成分,包括脂肪烃、芳香烃和含量很低的苯并吡咯等含氮化合物;根据色谱的保留时间将柴油中的同分异构体区分开来。结果表明GC/SPI-TOF MS法是一种简单、有效的分析方法,非常适于柴油及复杂环境样品等的分析表征。  相似文献   

12.
本文对合成的7种含硒芳香杂环化合物进行了GC/MS分析研究。结果表明:BS、MB、BBS和DBBS等4个化合物在色谱柱内的保留时间与它们的相对分子质量呈线性关系。所有化合物均可获得特征质谱,表现出含单个硒原子的分子离子或碎片离子特征峰簇,硒的两种主要同位素在峰簇中表现为主要峰M与(M-2)的相对丰度比约为2:1,可为鉴定含硒分子离子或碎片离子提供重要信息。新化合物1,2,5-硒二唑并[3,4-d]嘧啶-5,7-(4H,6H)二酮(SPDO)在色谱柱内出现11.83min和7.96min两个具有相同的质谱的色谱峰,被认为是互变异构体的峰。  相似文献   

13.
The mass spectral characteristics of wax esters were systemically summarized and interpreted through data mining of their standard mass spectra taken from NIST standard mass spectral library. Combining with the rules of retention indices described in the previous study, an automatic system was subsequently developed to identify the structural information for wax esters from GC/MS data. After tested and illustrated by both simulated and real GC/MS data, the results indicate that this system could identify wax esters except the polyunsaturated ones and the mass spectral characteristics are useful and effective information for identification of wax esters.  相似文献   

14.
Combinatorial chemistry is widely used within the pharmaceutical industry as a means of rapid identification of potential drugs. With the growth of combinatorial libraries, mass spectrometry (MS) became the key analytical technique because of its speed of analysis, sensitivity, accuracy and ability to be coupled with other analytical techniques. In the majority of cases, electrospray mass spectrometry (ES-MS) has become the default ionisation technique. However, due to the absence of fragment ions in the resulting spectra, tandem mass spectrometry (MS/MS) is required to provide structural information for the identification of an unknown analyte. This work discusses the first steps of an investigation into the fragmentation pathways taking place in electrospray tandem mass spectrometry. The ultimate goal for this project is to set general fragmentation rules for non-peptidic, pharmaceutical, combinatorial compounds. As an aid, an artificial intelligence (AI) software package is used to facilitate interpretation of the spectra. This initial study has focused on determining the fragmentation rules for some classes of compound types that fit the remit as outlined above. Based on studies carried out on several combinatorial libraries of these compounds, it was established that different classes of drug molecules follow unique fragmentation pathways. In addition to these general observations, the specific ionisation processes and the fragmentation pathways involved in the electrospray mass spectra of these systems were explored. The ultimate goal will be to incorporate our findings into the computer program and allow identification of an unknown, non-peptidic compound following insertion of its ES-MS/MS spectrum into the AI package. The work herein demonstrates the potential benefit of such an approach in addressing the issue of high-throughput, automated MS/MS data interpretation.  相似文献   

15.
Several compounds, representative of the class of lexitropsins, were analyzed by electrospray tandem mass spectrometry. The study of the fragmentations of the protonated molecular species ([M + H](+)) and of selected fragment ions allowed proposals for the main fragmentation pathways of compounds of this type. The interpretation of the fragmentation pathways of these compounds was complicated because of intramolecular hydrogen migration. In order to better understand the fragmentation pathways, the MS/MS/MS spectra of several compounds, and the MS/MS and MS/MS/MS spectra of the deuterated compounds, were obtained. Accurate mass measurements helped elucidate the structures of smaller fragment ions. Low-energy collision-induced decomposition (CID) tandem mass spectrometry of lexitropsins with electrospray ionization has proven to be a good method for the structural characterization and identification of this class of compounds. Main fragmentation pathways occur by cleavage of the peptide bond followed by the elimination of the substituted pyrrole ring, and their elucidation will facilitate structural characterization of new lexitropsins.  相似文献   

16.
17.
GC/MS定性分析中,由于同分异构体的质谱图相似,常常出现结构鉴定错误.同分异构体化合物的保留行为具有较大地差别,采用文献保留指数和保留温度测定值回归分析方法对2篇已发表论文进行了研究,发现了对单萜烯类同分异构体结构鉴定中存在的错误,并提出可能的正确结构.文献保留指数和保留温度测定值回归分析方法可以简化GC/MS色谱峰的定性分析过程,提高定性分析的准确性,在样品定性分析中具很强的使用价值.  相似文献   

18.
A gas chromatography/mass spectrometry (GC/MS) coupled system has been established for the confirmatory identification of abnormal urinary organic acids in inherited metabolic diseases. Samples of patient urines were extracted with an organic solvent and trimethylsilylated (TMS). A mass spectra of gas chromatographically separated TMS derivatives can be obtained using the GC/MS coupled system with a single analytical run. Those compounds with close methylene units (e.g., 4-hydroxyphenylacetaic acid and phenylpyruvic acid) in the gas chromatograph can be identified by their specific mass spectra. The results indicate that this GC/MS system is a powerful method for identifying abnormal urinary organic acids. These acids can be identified by comparison with authentic mass spectra established in our laboratories or with mass spectra files from other sources or they can be directly identified by analysis of the mass spectrum. By using this system, we were able to make positive identification of several inherited metabolic diseases found in Chinese patients, including phenylketonuria, propionic acidemia, and methylmalonic aciduria. This GC/MS system is a powerful tool for the diagnosis of inherited metabolic diseases.  相似文献   

19.
The heavy petroleum fractions produced during refining processes need to be upgraded to useable products to increase their value. Hydrogenated heavy paraffinic fractions can be oxidised to produce high value products that contain a variety of oxygenates. These heavy oxygenated paraffinic fractions need to be characterised to enable the control of oxidation processes and to understand product properties. The accurate identification of the oxygenates present in these fractions by electron ionisation (EI) mass spectrometry is challenging due to the complexity of these heavy fractions. Adding to this challenge is the limited applicability of EI mass spectral libraries due to the absence of molecular ions from the EI mass spectra of many oxygenates. The separation of oxygenates from the complex hydrocarbon matrix prior to high temperature GC‐MS (HT‐GC‐MS) analysis reduces the complexity of these fractions and assists in the accurate identification of these oxygenates. Solid phase extraction (SPE) and supercritical fluid chromatography (SFC) were employed as prefractionation techniques. GC‐MS with supersonic molecular beams (SMBs) (also named GC‐MS with cold‐EI) utilises a SMB interface with which EI is done with vibrationally cold sample compounds in a fly‐through ion source (cold‐EI) resulting in a substantial increase in the molecular ion signal intensity in the mass spectrum. This greatly enhances the accurate identification of the oxygenates in these fractions. This study investigated the ionisation behaviour of oxygenated compounds using cold‐EI. The prefractionation by SPE and SFC and the subsequent analysis with GC‐MS with cold‐EI were applied to an oxygenated heavy paraffinic fraction.  相似文献   

20.
本文给出了50余种C_nF_mH_1Br_x的色谱相对保留时间和质谱数据。还给出了热导检测器上Br(CF_2)_nBr的峰面积的相对响应值和一些化合物的质谱总离子流大小的相对响应值。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号