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1.
铝,镁,锌—氟哌酸配合物的荧光特性及其脂溶性研究   总被引:1,自引:0,他引:1  
探讨了介质PH值及Al^3-,Mg^2+,Zn^2+离子对喹诺酮类药物氟哌酸荧光特性的影响。发现铝,镁及锌离子在不同PH值条件下与氟哌酸形成配合物而增强荧光,据此建立了用铝离子增强荧光测定氟哌酸含量的新方法。  相似文献   

2.
本文用一步反应合成了未见文献报道的化合物AEu2I5(A=K,Rb,Cs),测定了这些化合物的组成、结构、熔点、密度、极谱电位、固体荧光光谱及在四氢呋喃中的紫外可见吸收光谱,解释了固体荧光光谱,确定了化合物中Eu的实际价态是+2。  相似文献   

3.
尹洪宗  朱贵云 《分析化学》1998,26(8):985-988
研究发现,镧、钆、镥、钇和钪和5种稀土离子可以分别与铽-乙酰基水杨酸形成优良的工分荧光体系。在最佳条件下,5种离子可分别使铽-乙酰水杨酸体系的荧光增强350、58、108、73和40倍。分别研究了各共发光体系的形成条件、荧光特点和影响因素,利用铽-镧-乙酰水杨酸体系,可使铽的检测 降到3.0×106-10mol/L,铽浓度在5.0×10^-9-3.0×10^-6mol/L范围内与荧光强度呈线性关系  相似文献   

4.
合成了Tb^3+和Eu^3+的N,N’,N”-1,3,5-三嗪-2,4,5-三-(N-羧甲基)-氨基乙酸配合物,并用元素分析、热重-差热分析、紫外吸收光谱、红外光谱、荧光光谱、磷光光谱等进行了表征。结果表明,该配体能够敏化Tb^3+的荧光,而不能敏化Eu^3+的荧光,根据配体磷光光谱对发光机理进行了讨论。  相似文献   

5.
偏最小二乘法用于荧光光度法同时测定铈,镨,铽   总被引:9,自引:1,他引:9  
贺立敏  任英 《分析化学》1992,20(2):128-132
本文将偏最小二乘法(PLS)用于荧光光度法同时测定铈、镨、铽。对荧光光度法的测定条件及PLS法中系列校准样品的实验设计及测量波长点的选择等进行了试验和讨论。所建立的方法用于天然混合稀土氧化物中铈、镨、铽的测定,获得较满意的结果  相似文献   

6.
用薄样X射线荧光光谱法测定较区91老年冠心病患者及63名老年健康人血清Zn、Cu、Ca、Mg、四种元素的含量。结果表明:牧区老年冠心病患者血清中Zn、Cu、含量与健康组比较无显著差异,但两者的比值高于对照组,可能与牧区牧民饮食习惯有关;老年冠心病组血清Ca、Mg含量显著低于对照组。  相似文献   

7.
在模拟生理环境下,通过稳态荧光光谱、时间分辨荧光光谱、傅立叶变换红外光谱和三维荧光光谱等方法研究了5'-羟基-2,2',4,4',5-五溴二苯醚(5'-OH-BDE-99)与人血清白蛋白的结合特征,并结合分子对接与分子动力学模拟技术对其作用机制进行了分析。荧光光谱实验、非辐射能量转移理论及动力学模拟研究表明,5'-OH-BDE-99能使HSA发生猝灭作用,且猝灭机制为静态猝灭。傅立叶变换红外光谱、三维荧光光谱及动力学模拟研究表明,5'-OH-BDE-99可诱导HSA构象和周围环境发生变化。此外,分子对接和热力学方法研究表明,二者间的主要作用力为疏水作用力。  相似文献   

8.
李红霞  黄汉国 《分析化学》1995,23(9):1036-1039
本文探讨了钐、铕-四环素、强力霉素、土霉素、金霉素络合物的荧光性能及利用该体体系以荧光分析光度法测定痕量钐和铕的可能性与最佳测定条件。结果表明:在高碱度条件下,以四环素体系的稳定性、灵敏性最好,钐和铕的检测限分别为38.2和0.09ng/mL。  相似文献   

9.
介绍X射线荧光光谱法定量测定钨铁合金(粉末)中的W,Fe,Si,Mn,Cu。试样经粉碎过筛后选取直径为53~63μm的粉末压制成型,对部分元素作基体校正,此方法快捷、准确、可靠,能满足生产上对快速分析的要求。  相似文献   

10.
吡嗪—2,3—二羧酸体系导数荧光法同时测定铕,铽   总被引:5,自引:0,他引:5  
研究了以吡嗪-2,3-二羧酸为荧光试剂应用导数荧光技术同时测定Eu^3+,Tb^3+的最佳条件,共存离子的影响和Eu^3+,Tb^3+-PYDA配合物的配合比,稳定常数及光机理,Eu^3+,Tb^3+的检测限分别达4.0和2.0ng/mL,利用本方法成功地测定了稀土试样中铕、铽的含量。  相似文献   

11.
The present paper cover a measurement system combining reflection spectroscopy photocurrent spectroscopy and photocapacitance spectroscopy, and a measurement system for time resloved reflection and transmission spectroscopy in the ultraviolet-visible spectral region built in suit to characterize electrochemistrical processes. A differential or subtractive spectral method with recpect to an electrode potential change has been adopted in both systems in order to obtain a high S/N ratio.  相似文献   

12.
Pretreatment of whey by microfiltration (MF) has emerged as a necessary step in producing high purity whey protein concentrates. In the MF of pretreated whey using a Carbosep M14 membrane (pore diameter 0.14 μm), proteins and calcium phosphate aggregates were responsible for fouling, which increased according to the “complete blocking” filtration law and accounted for a progressive decrease of the active filtering area. An operating mode with dynamic counter pressure (recirculation of the permeate co-current to the retentate), as opposed to static counter pressure, allowed lower overall fouling, a longer time of operation and better protein recovery because of more evenly distributed fouling along the membrane tube. At shorter times of operation, fouling was greater under higher transmembrane pressure (TP), so that the less fouled areas under lower TP were forced to filter larger volumes and consequently became fouled more rapidly. This involved a movement of the effective filtering area along the membrane tube, as evidenced by the systematic evolution of fouling heterogeneity as measured by infra-red spectroscopy.  相似文献   

13.
Since the theory of generalized two-dimensional (2-D) correlation spectroscopy was proposed, it has been keenly concerned in scientific research and its analytical method has been widely applied in various analytical fields. The mathematical process to construct generalized 2-D correlation spectroscopy and the physical meaning of 2-D correlation spectral map are described, and three examples in the fields of chemical analysis and molecular biology are provided, such as the component analysis of organic solvent, the analysis of biological molecules in the solvent with different pH values and structural analysis of protein. The theory and analytical method of generalized 2-D correlation spectroscopy are also detailedly commented.  相似文献   

14.
《Chemical physics letters》1987,137(4):324-329
A generalized pulse pair has been suggested in which the longitudinal spin order is retained and the transverse components cancelled by random variation of the interval between pulses, in successive applications of the two-dimensional NMR algorithm. This method leads to pure phases and has been exploited to provide a simpler scheme for two-spin filtering and for pure phase spectroscopy in multiple-quantum-filtered two-dimensional NMR experiments.  相似文献   

15.
Dealumination of zeolites is regarded as a useful postsynthesis method for the modification of Si/Al ratio. Among other compounds phosgene proved to be an excellent reactant for aluminium removal from zeolite frameworks. The interaction of zeolites with chlorofluorocarbons also leads to dealumination, resulting in the formation of a phosgene intermediate that has been proven by IR and NMR spectroscopy.  相似文献   

16.
After correlation analysis for general spectro- scopy, two-dimensional (2-D) correlation spectroscopy is obtained by extracting the information contained in the spectra in two dimensions, which is the function of two dependent spectral variables. 2-D correlation spectroscopy is initially regarded as an analytical data treatment method in the study of molecular interaction by using sinusoidal infrared sign[1]. In 1993, it was extended to generalized 2-D correlation spectroscopy, which used mo…  相似文献   

17.
The number of possible applications of NMR spectroscopy has rapidly increased during the past few years. New fields of applications have been opened by the development of supraconducting solenoids and various spin-decoupling techniques and by the method of “pulsed Fourier transform NMR-spectroscopy”. These methods originate mainly from progress in instrumentation. Recently, another “technique” has been introduced into NMR spectroscopy, which—principally on the basis of chemical and spectroscopic experience—is much less expensive but nevertheless useful. The basic principles, background, and most important applications of this method, known as the “NMR-shift-reagent technique”, form the subject of this paper.  相似文献   

18.
19.
微晶萘固相反射散射分光光度法测定钼的研究   总被引:7,自引:1,他引:6  
研究了微晶萘萃取钼与吡咯烷基二硫代甲酸铵配合物的条件,并设计了固相反射散射分光光度法直接测定萘相中钼的含量。方法有较好的选择性,可以在钨存在下直接测定地质样品中钼的含量,方法检出限为0.023μg/ml相对标准偏差为4.2%。  相似文献   

20.
We consider blind source separation in chemical analysis focussing on the 3D fluorescence spectroscopy framework. We present an alternative method to process the Fluorescence Excitation‐Emission Matrices (FEEM): first, a preprocessing is applied to eliminate the Raman and Rayleigh scattering peaks that clutter the FEEM. To improve its robustness versus possible improper settings, we suggest to associate the classical Zepp's method with a morphological image filtering technique. Then, in the second stage, the Canonical Polyadic (CP or Candecomp/Parafac) decomposition of a nonnegative three‐way array has to be computed. In the fluorescence spectroscopy context, the constituent vectors of the loading matrices should be nonnegative (since standing for spectra and concentrations). Thus, we suggest a new nonnegative third order CP decomposition algorithm (NNCP) based on a nonlinear conjugate gradient optimization algorithm with regularization terms and periodic restarts. Computer simulations performed on real experimental data are provided to enlighten the effectiveness and robustness of the whole processing chain and to validate the approach. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

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