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1.
从充分利用气相色谱/质谱(GC/MS)提供的信息来鉴定GC流出组分的目的出发,并以脂肪醇分析为例讨论了GC保留指数在MS谱图解析及MS鉴定结果的合理性检验方面的作用。总结了GC保留的同系物规律、极性规律、加和规律及异构物规律来指导MS谱图解析。提出了含氧化合物官能团相对于-CH2-质量数的保留指数附加贡献值辅助MS确定化合物的类别。同时采用了GC/MS中选择离子检测方法(SIM)在分子离子峰受噪音干扰或太弱以至完全未观测到时来进一步佐证其相对分子质量。  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.
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   

4.
本文报道用MS/MS技术的一种重要实验方法——能量分辨质谱(ERMS)来鉴别质谱分析中的同分异构体化合物。系统探讨了同分异构的硝基芳香化合物2,3-DNT和3,5-DNT(相对分子质量为182)在电子轰击(EI)方式下,裂分途径与其分子内能的相互关系以及离子的结构和裂分途径相对于碰撞能量(CE)的依赖关系(裂分曲线)。结果表明,利用同分异构化合物在能量分辨中的显著差异可以辨别它们的结构  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.
1,2-二(1-茚基)四甲基二硅烷相继与本基锂及MCl4·2THF作用。生成四甲基二硅桥连二(1-茚基)钛和锆化合物(Me2SiSiMe2)「Ind」2CMl2「M=(Ti(1),Zr(2)」,对其进行催化氢化,得到相应的四氢茚基化合物(Me2SiSiMe2)「IndH4」2MCl2「M=Ti(3),Zr(4)」通过元素分析,MS和HNMR谱表征了化合物的分子结构,并了在MAO的助催化下,化合物3  相似文献   

7.
1-氮代杂氮锗三环与羧酸钾盐反应生成1-酰氧基杂氮锗三环化合物。通过IR,^1HNMR和质谱确定了它们的结构,测定了化合物SCH=CHCHC-COOGe(OCH2CH2)3N的晶体结构,化合物为五配位,N→Ge键长为0.212nm。  相似文献   

8.
宋凤瑞  刘子阳 《分析化学》1998,26(7):865-867
建立了麻醉痛药物的电子轰击/串联质谱分析方法,得到了电子轰击/串联质谱(EI/MS/MS)条件下16种麻醉镇痛药物标准品的碰撞诱导解离(CID0-子离子谱,适合于复杂基质中这类化合物的定性分析,并利用所建方法对一肌注度冷丁者的尿样进行了检测。  相似文献   

9.
二烃基锡双(O,O-二硫代磷酸酯)的合成和波谱研究   总被引:1,自引:0,他引:1  
合成了15个二烃基双(O,O-二硫代磷酸酯)化合物。利用IR、(1H、13C、119Sn)NMR表征了化合物的结构。这是一类六配位变形八面体结构的二烃基锡化合物。对化合物的质谱裂解机制进行了讨论。  相似文献   

10.
室温下[Et_4N]_2MoSe_4, FeCl_2和 R_2NCS_2Na在 DMF和 CH_3CN混合溶剂中反应,得到含MoFe_3Se_4核芯的Mo-Fe-Se簇合物MoFe_3Se_4(μ-R_2NCS_2)_2(R_2NCS_2)_4(R2=Me_2(1),Et_2(2),C_4H_8(3)).化合物2的单晶X射线衍射分析表明,其分子结构为2个桥式和4个螫合Et_2NCS_2~-配体包围的一个扭曲类立方烷M_4Se_4簇核对3个化合物的CV进行了表征,它们在DMSO溶液中的电化学行为表现出了多电子可逆的传递过程.  相似文献   

11.
A theoretical investigation of the fully optimized geometries and electronic structures of the metal-free (TPdPzH(2)), N,N'-dideuterio (TPdPzD(2)), and magnesium (TPdPzMg) tetra-2,3-pyridino-porphyrazine has been conducted based on density functional theory. The optimized geometries at density functional theory level for these compounds are reported here for the first time. A comparison between the different molecules for the geometry, molecular orbital, and atomic charge is made. The substituent effect of the N atoms on the molecular structures of these compounds is discussed. The IR and Raman spectra for these three compounds have also been calculated at density functional B3LYP level using the 6-31G(d) basis set. Detailed assignments of the NH, NM, and pyridine ring vibrational bands in the IR and Raman spectra have been made based on assistance of animated pictures. The simulated IR spectra of TPdPzH(2) are compared with the experimental absorption spectra, and very good consistency has been found. The isotope effect on the IR and Raman spectra is also discussed.  相似文献   

12.
Fifteen of the bichromophore compounds containing oxazole or oxidation ring have been synthesized. Their structures have been identified by IR, 1H NMR spectra and elemental analysis. The UV spectra, fluorescence spectra and the laser conversion efficiencies have been determined . The results of determination show that the absorption and emission spectra Pf the bichromophore compounds are different from those of the corresponding single chromophore compounds.  相似文献   

13.
The possibility of identification based on the comparison of experimental electron-ionization mass spectrum of an unknown (in our case, model) compound with the mass spectra of the candidate compounds generated by the Mass Frontier software has been demonstrated by the example of three model compounds. The structural isomers of the identified substances found in the ChemExper database have been used as the candidate compounds. The candidate substances have been ranged by the degree of similarity between their simulated mass spectra and the experimental mass spectrum of the unknown compound. The mass spectra have been compared on the basis of the algorithm used in the NIST MS Search standard search system. In all three cases, the sought-after structure has been indicated as the most probable one of all the candidate structures.  相似文献   

14.
In the present work, the molecular structures of two new synthesized dyes:(4,6-dimethylpyrimidin-2-ylamino)(5-p-tolylisoxazol-3-yl)methanol(PS-1) and N-(4,6-dimethylpyrimidin-2-yl)-5-phenylisoxazole-3-carboxamide(PS-2), have been investigated using density functional theory(DFT) in dimethylformamide(DMF) for the first time. The electronic spectra of new dyes in a DMF solvent were carried out by time dependent density functional theory(TD-DFT) method. After quantum-chemical calculations two new dyes for the optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. NucleusIndependent Chemical Shifts(NICS) calculations have also been carried out for the title compounds. The computed absorption spectral data of the title compounds are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The HOMO and LUMO molecular orbitals, excitation energies and oscillator strengths for the dyes have also been calculated and presented.  相似文献   

15.
The 13C NMR spectra of a series of 3,5,7(11)-eudesmatrien-6,12-olides and of 1,3,5,7(11)-eudesmatetraen-6,12-olides have been assigned. The spectra of some model compounds containing the 5,7(11)-eudesmadien-6,12-olide chromophore have also been recorded.  相似文献   

16.
本文研究了鳞翅目昆虫性外激素——长链单不饱和脂肪醇乙酸脂系列化合物的红外和拉曼光谱。对主要谱带进行了归属。探讨了十一种系列化合物在室温液态和低温固态的光谱差异,得到了某些特征带与链结构的关系。结合其它物理性质,它们可用于估计同系物的双键位置和链长。  相似文献   

17.
The IR and Raman spectra of three isotopic varieties of the ethylenediammonium ion in the tetrachlorocadmate(II) have been measured. It is shown that the ion assumes the centrosymmetric trans conformation in this salt. A complete vibrational assignment has been proposed for the observed fundamentals. Certain assignments for related compounds in the literature are modified. The spectra of the ion in the hexachloroplatinate(IV) and hexachlorostannate(IV) have also been obtained; compared to these two compounds hydrogen bonding in the tetrachlorocadmate is appreciable. Combination bands observed in the 2100-1800 cm?1 region of the IR and Raman spectra of compounds containing the C-NH3+ grouping are discussed and assignments are suggested for those observed in ethylenediammonium salts.  相似文献   

18.
Corsini A  Louch WJ  Thompson M 《Talanta》1974,21(3):252-255
The PMR spectra of 8-hydroxyquinoline and eighteen derivatives have been obtained at 220 MHz. For several of the compounds, PMR spectra have not been reported previously. The use of 220-MHz frequency considerably facilitates the interpretation of spectra from such complex derivatives as 2-(2'-pyridyl) and 2-(2'-thienyl)-8-hydroxyquinoline.  相似文献   

19.
1,4—双(苯基乙炔基)苯及其双取代苯基衍生物的研究   总被引:2,自引:1,他引:2  
合成了1,4-双(苯基乙炔基)苯及其双取代苯基衍生物。测定了它们的荧光量子产率、激光转换效率、红外光谱、拉曼光谱,指派了主要官能团的特征频率,讨论了化合物结构和取代基效应。  相似文献   

20.
Three new derivatives of thiosemicarbazides, derived from the reactions of ethyl-, allyl- and phenyl isothiocyanates with Girard's T [(carboxymethyl) trimethylammonium chloride hydrazide] and P [1-(carboxymethyl) pyridinium chloride hydrazide], have been isolated and characterized by chemical analyses, conductivities, spectral (IR, 1H NMR) and molecular weight measurements. The most important assignments of the functional groups in the isolated solid organic compounds have been determined using IR spectra. Also, the main functional groups in the skeleton of these compounds have been characterized using 1H NMR spectra. Moreover, a comparative studies between the three thiosemicarbazide derivatives have been carried out. The role of the existence of ethyl-, allyl-, phenyl-, [(CH3)3N+-] and [C5H5N+-] on the position of the functional groups has been investigated. Finally, the absence of any type of hydrogen bonding (inter- and/or intra-) within these compounds is discussed on the basis of the data of melting points, IR and 1H NMR spectra and molecular weight measurements.  相似文献   

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