共查询到20条相似文献,搜索用时 187 毫秒
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设计并合成了一种卟啉类光敏剂与抗癌药羟基喜树碱通过共价键相连的四(对-乙酰氧醚-10-羟基喜树碱)苯基卟啉化合物. 通过紫外光谱、 红外光谱、 核磁氢谱和质谱分析等手段对其结构进行了表征. 在癌症治疗过程中目标化合物中2种药物可能起到一定的协同效应. 相似文献
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应用拉曼光谱法进行定量分析的几个关键性技术问题 总被引:5,自引:0,他引:5
应用拉曙谱法进行定量分析,不仅要从拉曼光谱分析理论的本继续进行深入的探讨和研究,而且还要从实验室分析操作的技术理论和技术方法上进行深入的探讨和研究。本文着重就应用拉曼光谱法进行定量分析时,分析曲线非线性的产生及内外标法的概念与正确运用、提高光谱强度的技术问题,分析曲线的绘制及光谱谱峰的积分,对拉曼光谱仪各种不同参数的正确理解与选择等关键性技术问题进行了深入的讨论,为形成完整的拉曼光谱法定量分析理论 相似文献
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采用魔角旋转固体核磁碳谱法(MAS–~(13)CNMR)测定硫化丁苯橡胶中的苯乙烯含量。通过固体核磁碳谱解析,对丁苯橡胶中苯乙烯、1,2-乙烯基、1,4-丁二烯的特征峰进行归属分析,以固体核磁外标法定量。对已知苯乙烯含量的标准样品进行测定,绘制校正曲线,结果显示理论苯乙烯含量与固体核磁法计算结果成良好的线性关系,线性相关系数(r~2)为0.97。经标准曲线校正后的苯乙烯含量接近于真实值,计算结果的相对误差小于5%,测定结果的相对标准偏差为0.31%(n=6)。该方法适用于单一胶种的硫化丁苯橡胶中苯乙烯含量的检测。 相似文献
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以2,4-二羟基二苯甲酮、4-羟基苯乙酮(HAP)为原料分别和环氧氯丙烷反应,经微波辐照合成了两种反应性紫外线吸收剂2-羟基-4-缩水甘油醚基二苯甲酮(HEPBP)和4-缩水甘油醚基苯乙酮(EPAP)。结构采用红外光谱、核磁和质谱表征。最佳合成条件为:n(羟基芳香酮)∶n(环氧氯丙烷)=1∶3,微波功率400W,于90℃反应15min,收率分别是52.6%和58.3%。与常规合成方法比较,微波合成法能降低反应温度、大大地缩短反应时间。产物中环氧丙烷基团的引入能明显改善芳香酮类紫外线吸收剂的紫外吸收性能。 相似文献
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以硫代水杨酸和苯硫乙酸为原料,通过两步法成功合成了一种新型的单组分硫杂蒽酮类光产碱剂。利用核磁氢谱、核磁碳谱和高分辨率质谱对光产碱的结构进行了表征,通过稳态光解及电子自旋共振波谱等对光解产物进行了系统研究。该光产碱剂在400nm附近有较强的吸收,可有效引发巯基-环氧光聚合,其引发活性优于文献报道的高效光产碱体系。 相似文献
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毛侦军 《分析测试技术与仪器》2022,28(1):31-36
报道了盐酸帕罗西汀的分子结构解析方法,利用国产核磁共振波谱仪测试了盐酸帕罗西汀核磁氢谱(^(1)H-NMR)、核磁碳谱(^(13)C-NMR、DEPT 135°)、二维核磁相关谱(^(1)H-^(1)HCOSY、^(13)C-^(1)H HSQC、^(13)C-^(1)H HMBC),实现了盐酸帕罗西汀氢碳的全部归属. 相似文献
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《Magnetic resonance in chemistry : MRC》2003,41(7):509-516
Details of a new flow NMR technique, flow injection analysis NMR (FIA–NMR), are presented for the first time. This method blends some aspects of both liquid chromatography–NMR and direct injection NMR, and complements both. FIA‐NMR is shown to be useful as an analytical technique, especially for repetitive analyses, and may also prove useful in the analysis of combinatorial chemistry libraries. The feasibility of FIA‐NMR is demonstrated by the quantitative analysis of an over‐the‐counter pharmaceutical. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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Joaquim Jaumot Montserrat Vives Raimundo Gargallo Rom Tauler 《Analytica chimica acta》2003,490(1-2):253-264
One of the difficulties frequently encountered when studying acid–base equilibria with NMR spectroscopy is the labile behaviour of the measured signal, which hinders the application of bilinear multivariate data analysis methods. In this work, a mathematical transformation is proposed for the conversion of NMR labile signals to inert signals, which make possible the application of multivariate data analysis methods, based on bilinear data models. The procedure has been applied to the analysis of NMR data corresponding to the acid–base equilibria of nucleotides dCMP and dGMP. Both hard-modelling (EQUISPEC) and soft-modelling (MCR-ALS) approaches have been applied for the analysis and resolution of transformed bilinear NMR data matrices. 相似文献
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The main achievements of high-resolution NMR spectroscopy in combination with different chemometric methods in the analysis of food products in the last 40 years are reviewed. The essence of chemometric methods used for the analysis and interpretation of NMR spectra is briefly described. Sample preparation for NMR-spectroscopic analysis is characterized. Methods for the mathematical treatment of NMR spectra (smoothing, Fourier transformation, bucketing, normalization, and selection of spectral ranges) are considered. Currently available methods for the suppression of the signals of macrocomponents, including those for the simultaneous suppression of several signals, are described. The results are illustrated based on examples of analysis of different classes of foodstuffs and beverages with the use of NMR spectroscopy and chemometric methods for classification and discrimination (geographical and botanical origin as well as validating checking the brand authenticity). 相似文献
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介绍了国产1.5T核磁共振弛豫时间分析仪的基本组成、性能指标,研发过程中攻克的技术难题。该仪器主要由磁体部分、电子部分、软件部分组成,具有体积小、信噪比高、检测无损、使用和维护简便和造价低廉等优点。同时对该系统磁体频率和磁信号的稳定性进行了相关的测试,结果表明该系统稳定可靠。该仪器的磁场强度增加到1.5T,在同等外界条件和环境下,信噪比增加约为0.5T系统的10倍,检测灵敏度大幅度提高;该仪器为食品品质鉴定、食品安全检测、医学诊断、生物标志物的大规模筛选等生化分析提供一个全新的途径。 相似文献
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The application of NMR spectroscopy, including its up-to-date versions (correlation homo- and heteronuclear spectroscopy, Overhauser effect, solid-state NMR, etc.), to the analysis of tobacco and tobacco products, tea, and coffee is considered. The advantages and limitations of NMR techniques in the analysis of complex mixtures, as compared with chromatography-mass spectrometry and other instrumental techniques, are discussed based on particular examples. 相似文献
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Prof. Bernhard Blümich Kawarpal Singh 《Angewandte Chemie (International ed. in English)》2018,57(24):6996-7010
NMR spectroscopy is an indispensable method of analysis in chemistry, which until recently suffered from high demands for space, high costs for acquisition and maintenance, and operational complexity. This has changed with the introduction of compact NMR spectrometers suitable for small‐molecule analysis on the chemical workbench. These spectrometers contain permanent magnets giving rise to proton NMR frequencies between 40 and 80 MHz. The enabling technology is to make small permanent magnets with homogeneous fields. Tabletop instruments with inhomogeneous fields have been in use for over 40 years for characterizing food and hydrogen‐containing materials by relaxation and diffusion measurements. Related NMR instruments measure these parameters in the stray field outside the magnet. They are used to inspect the borehole walls of oil wells and to test objects nondestructively. The state‐of‐the‐art of NMR spectroscopy, imaging and relaxometry with compact instruments is reviewed. 相似文献
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合成了八种新的四氟硼酸二甲基苯基锍,用元素分析和核磁共振对其结构进行了表征。研究了以CDCl~3为溶剂,NMR位移试剂Eu(fod)~4^-对所合成锍盐的^1H和^1^3C NMR的影响。结果表明,Eu(fod)~4^-是一个对锍盐非常有效的位移试剂,且Eu(fod)~4^-对二甲基苯基锍盐之甲基的^1H和^1^3C NMR的位移呈线性关系。 相似文献