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 共查询到19条相似文献,搜索用时 453 毫秒
1.
评述了以超分子化学分子识别为基础发展起来的新型阴离子目视显色剂,内容主要包括显色剂对选择性阴离子的显色属性以及显色属性和显色剂结构的关系.  相似文献   

2.
显色剂性能的量子化学方法(PPP法)研究   总被引:1,自引:0,他引:1  
编制了适于有机显色剂电子结构与光谱性能研究的PPP法计算程序。用此程序计算了吡啶偶氮显色剂系列,并对部分显色剂进行实验,结果发现计算与实验的长波吸收波长有较好的一致性。  相似文献   

3.
介绍催化光度法测定锰的分析方法,讨论各显色体系中的灵敏度、测定范围和干扰情况,比较了测定锰的显色剂。引用文献58篇。  相似文献   

4.
李华  杨翌秋  许禄  苏锵 《化学学报》1995,53(12):1163-1167
本文计算了二十种不对称色酸双偶氮膦酸型显色剂的Am指数, 并将其与钇进行显色反应的灵敏度进行相关性研究, 讨论了显色剂结构对显色反应灵敏度的影响,预报了几种显色剂与钇显色反应的灵敏度, 取得较为满意的结果。  相似文献   

5.
熊言林  马珊珊 《化学教育》2012,33(10):1-2,19
简要介绍了双酚A的性质、合成方法、用途、毒性;以及以双酚A为显色剂的产品--热敏纸的概念、分类及其表层涂料中的化学品成分等。  相似文献   

6.
变色酸双偶氮类试剂是近十多年来新崛起的一种高灵敏度和高选择性的光度显色剂。在稀土元素的光度分析方面,变色酸双偶氮衍生物比单偶氮衍生物更有实用价值。而在变色酸双偶氮衍生物中,它对稀土元素的分析性能又以不对称型显色剂优于对称型显色剂。我国分析工作者在不对称变色酸双偶氮类稀土显色剂的研制和应用方面进行了不少工作,也取得了一些新的成果。作者在以往对不对称变色酸双偶氮氯膦型显色剂系统研究的基础上,继续保留主要分析  相似文献   

7.
编辑同志: 贵刊1983年第5期刊登了周复元同志的信。信中谈到当显色剂在测定波长处也具有光吸收时,过量显色剂的存在生产两个方面的问题。对于问题一,我同意信中的看法,而对于问题二,我认为不是由于显色剂存在而引起的,而是由于显色剂在测置波长处有光吸收(即ε_R>0)引起的。由作者信  相似文献   

8.
介绍了铜净化液中低含量铜的自动标准加入吸光光度分析方法,利用流动注射装置采集微量试样及标准,并自动加入显色剂将采集的试样送进带电磁搅拌器的微型反应池中进行反应。以硫代米Chi酮(TMK)为显色剂建立了铜净化液中0.15~1.00g.L^-1范围铜的测定方法,消除了铁和产生的基体影响,测定速度为20样.h^-1。  相似文献   

9.
李华  许禄 《高等学校化学学报》1995,16(10):1523-1526
计算了43种不对称变色酸双偶氮膦酸型显色剂的Am拓扑指数,并将其与结构选择性因子相结合,用于偶氮类显色剂结构与铈显色反应对比度的相关性研究,讨论了显色剂结构对拓扑指数有译比度的影响。  相似文献   

10.
光学分析试剂   总被引:8,自引:0,他引:8  
光学分析试剂是建立有关光学分析方法的物质基础,在许多领域中具有极强的应用背景。本文介绍若干种光学分析试剂尤其是高分子显色剂的研究进展。  相似文献   

11.
Schilt AA  Wu JF  Case F 《Talanta》1976,23(7):543-545
Preparation and metal-ion chromogenic properties of five new 2,4,6-trisubstituted pyrimidines containing pyridyl and methyl or phenyl groups are described. All five exhibit specific chromogenic reactions with copper(I), and two possess suitable characteristics for use as sensitive spectrophotometric copper reagents. The results obtained are also of interest in designing related chromogenic reagents.  相似文献   

12.
Multiple-component determinations present difficulties which cannot be resolved mathematically when there is severe spectral overlap, as in the determination of rare-earth elements with chromogenic reagents. The interdependence of absorptivities is greatly decreased when absorbance data from procedures based on several chromogenic reagents are used together in the calculations of calibration factors and concentrations. Various features of the method are discussed.  相似文献   

13.
新的不对称变色酸双偶氮衍生物的合成及其结构对稀土、钍、铋显色反应的影响张华山,张军锋,黎心懿(武汉大学化学系,武汉,430072)关键词变色酸双芳基偶氮衍生物,稀土,钍,铋,分光光度法变色酸双偶氮衍生物是光度法测定稀土、钍等金属的重要显色剂。其中多卤...  相似文献   

14.

Many specific and non-specific chromogenic spray reagents have been used to detect organic pesticides (organophosphorus, organochlorine, carbamates, and pyrethroids) on thin-layer chromatographic (TLC)/high-performance thin-layer chromatographic (HPTLC) plates. To realize high sensitivity and improved selectivity, several chromogenic reagents have been introduced. The physical properties of organic pesticides reported so far are also presented in tabular form. The colors produced on TLC plates due to reactions taking place between pesticides and spray reagents are illustrated in the form of chromatograms, and reaction mechanism is also presented.

  相似文献   

15.
从光度法测定人发中Zn(Ⅱ)的重要显色剂出发,对近年来人发中Zn(Ⅱ)的光度测定进展作一综述。  相似文献   

16.
This critical review is focused on examples reported in the year 2009 dealing with the design of chromogenic and fluorogenic chemosensors or reagents for anions (264 references).  相似文献   

17.
A double-line sequential injection system was developed for the spectrophotometric determination of several metal ions in waters. The proposed double-line configuration was used to enable adding sample and chromogenic reagents as merging zones. The methodology was applied to the spectrophotometric determination of copper, iron, manganese, and zinc in samples of diverse origins at the range of 0.15-5.00, 0.10-10.0, 0.48-4.00, and 0.11-5.00 mg/L, respectively. Different chromogenic reagents and detection wavelengths were used. The chromogenic reagents for iron and manganese were 1,10-phenanthroline and formaldoxime, respectively. Copper and zinc were both determined using the analytical reagent zincon. Analytical characteristics of the methodology, such as manifold parameters, buffer pH, and reagent concentrations were optimized, and interference of some of the metal ions commonly present in water sample was assessed. Results of the analysis were in agreement with those obtained by atomic absorption spectrometry. Repeatability, expressed as the relative standard deviation for 10 consecutive injections of water samples, was lower than 6%. The determination rate was approximately 36/h.  相似文献   

18.
The main methods for the determination of local anesthetics are considered, and their advantages and disadvantages are discussed. After the systematization of published data, it was established that the greatest number of works were devoted to the determination of novocaine, lidocaine, and ultracaine; therefore, methods for their determination are considered separately. It was demonstrated that the extraction and sorption preconcentration of local anesthetics as ion associates with chromogenic organic reagents is promising. It was substantiated that the development of combined rapid and sensitive extraction-photometric, sorptionspectroscopic, and colorimetric methods for the determination of novocaine, lidocaine, and ultracaine with chromogenic organic reagents in different test materials is a problem of considerable current interest.  相似文献   

19.
A spectrophotometric procedure for the determination of six pharmaceutical sulfonamides containing a primary aromatic amino group using alizarine (I), alizarine blue (II), alizarine red (III), and quinalizarine (IV), that offers advantages of simplicity, rapidity, sensitivity, precision, and stability, has been developed. The proposed method is based on the formation of colored products with the chromogenic reagents (I-IV). A linear correlation was found between absorbance at λmax and the concentration. For more accurate results, Ringbom optimum concentration ranges are evaluated. The molar absorptivities (ε), absorptivities (a), and Sandell sensitivities for all sulfonamides derivatives with the chromogenic reagents tested were calculated. The procedures developed are applied for bulk sulfa drugs and some of their dosage forms.  相似文献   

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