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1.
导数吸附伏安法同时测定柠檬黄及日落黄   总被引:9,自引:0,他引:9  
色素日落黄和柠檬黄在pH8.2的硼酸钠-酸介质中均有良好的吸附伏安波,但波峰相互重叠,难以同时测定。本文提出以二阶导数法对日落黄和柠檬黄的重叠伏安波谱进行分析,以达到日落黄和柠檬黄同时测定的目的,方法简便快速。本法分析几种饮料中的日落黄及柠檬黄,结果满意。  相似文献   
2.
《Analytical letters》2012,45(7):781-792
Abstract

A rapid second-derivative spectrophotometric assay procedure has been described for the determination of some benzenoid drugs in pharmaceutical dosage forms. Spectral interference from formulation excipients in simple uv spectrophotometric methods has been eliminated by the application of the proposed method. The different assay parameters, linearity and precision of the method have been assessed. The assay results obtained for eight batches of the pharmaceutical formulations of these drugs are in accord with the declared amounts. The high specificity, ease and simplicity offered by second-derivative spectrophotometry permit unit dose assay of these formulations.  相似文献   
3.
二阶导数光谱峰面积法测定中草药中微量锗   总被引:4,自引:0,他引:4  
李红玫  卢利军  辛红 《分析化学》2002,30(12):1504-1506
在Ge 苯基荧光酮 (PF) 氯化十六烷基吡啶 (CPC)三元络合物的显色体系中 ,引入二阶导数光谱峰面积技术 ,对锗的显色体系及测定方法进行了研究。该方法有效地消除了W 、Sn 、Mo 、V 、Ti 和Fe(Ⅲ )等离子的干扰 ,提高了准确度和选择性。线性范围为 0~ 1 5mg L,检出限为 3 .3 μg L ,εGe为 1 .4× 1 0 5L·mol- 1 ·cm- 1 。用于中药材中Ge 的测定 ,标准加入试验的回收率为 1 0 1 .0 %~ 1 1 2 .0 %。  相似文献   
4.
The Skyrme-Faddeev-Niemi (SFN) model, which is an O(3) σ model in three dimensional space, upto fourth-order in the first derivative is regarded as a low-energy effective theory of SU(2) Yang-Mills theory. One can show from the Wilsonian renormalization group argument that the effective action of Yang-Mills theory recovers the SFN in the infrared region. However, the theory contains an additional fourth-order term which destabilizes the soliton solution. In this paper, we derive the second-derivative term perturbatively and show that the SFN model with the second-derivative term possesses soliton solutions. Presented at the International Colloquium “Integrable Systems and Quantum Symmetries”, Prague, 16–18 June 2005.  相似文献   
5.
This article gives the details of the methodology used in constructing a symbolic algebra program designed for evaluating potentials as the functional derivatives of so-called functional generators in molecular density-functional theory. The derived formulae are used in illustrative examples involving partial functional integration, the comparison of the exchange potential arising from different mathematical representations of the electron density for a given functional generator, and the evaluation and comparison of the potential for different functional generators with a given density. © 1998 John Wiley & Sons, Inc. J Comput Chem 19: 300–307, 1998  相似文献   
6.
In this paper the second-derivative spectrophotometric method for the simultaneous determination of some analgetic ingredients was described. Optimal conditions for the quantitative analysis of the three-component analgetic mixture of Dalivon® tablets were settled. The second-derivative order of the spectra in sodium hydroxide with the wavelength modulation was used. For the determination of paracetamol the “zero-crossing” technique was applied, but for propyphenazone and caffeine the characteristic peak amplitude had to be corrected.

The authors propose this second-derivative spectrophotometry for a rapid, simple, precise and accurate determination of the Dalivon® tablets or a corresponding multicomponent mixture.  相似文献   
7.
A spectrophotometric stability—indicating method is presented for the determination of famotidine in the presence of its degradation products. The method is based on measuring the peak height of the second—derivative maximum at 304 nm. The proposed method is used for the analysis of famotidine in its pharmaceutical dosage forms. The results obtained were precise and accurate.  相似文献   
8.
The interaction of Co(Ⅱ) with BSA under UV C (253.7 nm) irradiation under physiological conditions has been studied by UV-vis spectrum, ultraviolet second-derivative spectroscopy and fluorescence spectrum. The quenching rate constant kq and the association constant Ka were calculated according to Stern-Volmer equation based on the quenching of the fluorescence of BSA by Co(Ⅱ).  相似文献   
9.
近红外光谱在蛋白质和含酰胺基团聚合物研究中的应用*   总被引:1,自引:0,他引:1  
江艳  武培怡 《化学进展》2008,20(12):2021-2033
近红外光谱(near-infrared spectroscopy,NIR)是一种常用的无损表征手段,但谱带强度弱、交叠情况严重等缺点局限了它的应用范围。本文介绍了几种常见的改善近红外光谱技术不足的方法,如二阶导数法、二维相关光谱法和化学计量法等,并举例阐述了近红外光谱在蛋白质和含酰胺基团聚合物的结构和含量等方面的应用。这些方法对近红外光谱的定性定量分析起了很好的辅助作用,有效地拓宽了近红外光谱技术的应用领域。  相似文献   
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