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1.
《Analytical letters》2012,45(10):1799-1809
Abstract

Two acid dye reagents have been utilized for spectrophotometric determination of triamterene in pure form and in pharmaceutical preparations. The dyes used are bromophenol blue (B. P. B), and bromothymol blue (B. T. S. They form a chloroform-soluble, coloured ion association complex with triamterene, at pH 3.4 and 3.2 using B. P. B and B. T. B, respectively. The formed complex could be extracted and measured spectrophotometrically at 417 nm for both dyes. The molar ratio of the formed drug-dye ion association complex is found to be 1:1 for both dyes used, as deduced by applying Job's method. Linearity was obtained using concentration ranges of 2.5–10 μg, and 2.5–15 μg. ml?1 of triamterene with B. P. B. and B. T. B. respectively. The validity of the procedure was assessed by applying the standard addition technique. Results obtained by using the proposed procedure were statistically analysed and compared with those obtained by adopting the pharmacopoeial method.  相似文献   

2.
The absorption spectra of aqueous solutions of monochlorotriazine reactive dyes, C.I. Reactive Red 9 and Reactive Orange 13 were measured in the presence of 5, 10, 25 and 50% (v/v) of ethanol, pyridine and dioxane-water mixtures and in varied concentrations of KCl, NaCl and LiCl. The varying position, intensity and shape of absorption bands are interpreted in terms of aggregation and disaggregation of dyes in solutions. The aggregation behaviour of the reactive dyes in solutions and in the presence of additives is related to their apparent deviations from Beer's law and aggregation numbers (N). The aggregation constant (K.) of the monomer/dimer equilibrium is calculated. Dyes in ethanol-water mixtures record a larger aggregation number and aggregation constant than in the presence of pyridine. Dioxane is classified as anon-polar solvent and hence has a more disaggregating influence. The value of the aggregation number and constant are increased with increasing salt conentration and the order of degree of aggregation is KCl > NaCl > LiCl related to the order of ionic radii of K+, Na+ and Li+ ions.  相似文献   

3.
在B-R缓冲溶液中,藻酸钠与维多利亚蓝4R、维多利亚蓝B、夜蓝等碱性二苯基萘基甲烷染料发生反应,形成结合产物,染料发生明显的褪色.对于不同染料,最大褪色波长分别位于612 nm(维多利亚蓝4R体系)、616 nm(维多利亚蓝B体系)、614 nm(夜蓝体系).体系吸光度的降低与藻酸钠的质量浓度成正比.藻酸钠的质量浓度在5.0 mg·L-1(维多利亚蓝4R体系)、3.0 mg·L-1(维多利亚蓝B体系)、3.0 mg·L-1(夜蓝体系)以内符合比耳定律,摩尔吸光率根据染料的不同在4.8×106~9.5×106 L·mol-1·cm-1之间,其中以维多利亚蓝4R体系最为灵敏,对藻酸钠的检出限为21 μg·L-1.以维多利亚蓝4R体系为例研究共存物质的影响,表明方法选择性好.此法用于面条样品中藻酸钠的分析测定,结果满意.  相似文献   

4.
In weak acidic medium, anticancer antibiotics bleomycin A5 (BLMA5) and bleomycin A2 (BLMA2) can react with halofluorescein dyes such as erythrosin (Ery), eosin Y (EY), eosin B (EB) and rose bengal (RB) by virtue of electrostatic attraction and hydrophobic force to form the ion-association complexes, which can result in the fading reactions of four halofluorescein dyes. The maximum fading wavelengths of these four dyes were located at 527 nm for Ery, 515 nm for EY, 517 nm for EB and 546 nm for RB, respectively. The decrements of absorbance (AA) were directly proportional to the concentrations of bleomycin in a certain range. A new method for the determination of bleomycins anticancer drugs based on fading reactions of halofluorescein dyes has been developed. The method was not only highly sensitive but also simple and rapid. The molar absorptivities (ε) ranged from 1.5 × 10^5 to 7.5 × 10^5 L·mol^-1·cm^-1. It was applied to determination of the bleomycins in human serum, urine and rabbit serum samples. In this work, the spectral properties and the optimum reaction conditions were investigated. The structure of ion-association complexes and the reaction mechanism were discussed.  相似文献   

5.
在弱酸性的HAc-NaAc缓冲溶液中,藻酸钠与乙基紫、结晶紫和甲基紫等三苯甲烷碱性染料发生反应,形成结合产物使染料发生褪色,且对于不同的染料,最大褪色波长分别为594 nm(乙基紫体系)、584 nm(结晶紫、甲基紫体系)、616 nm(孔雀石绿体系)。藻酸钠浓度分别在0~5.0 mg/L(乙基紫、甲基紫体系)0、~3.0 mg/L(结晶紫体系)0、~2.0 mg/L(孔雀石绿体系)范围内符合比耳定律;摩尔吸光系数根据染料的不同在3.6×105~4.8×106L.mol-1.cm-1之间,其中以乙基紫体系最灵敏,对藻酸钠的检出限为29 ng/mL。以乙基紫体系为例研究了共存物质的影响。此法灵敏度高,选择性好,用于含藻酸钠的可立凝样品的分析测定,结果满意。  相似文献   

6.
Enolisation of acetoacetanilide (AAAH) acetoacet ortho-toluidide (AATH), 2, 4-acetoacetxylidide (AAXH), acetoacet-ortho-chloroanilide (CAAAH), acetoacetortho-anisidide (OAAAH), benzoyl-acetanilide (BAAH) and benzoyl-meta-nitro-acetanilide (NBAAH) have been studied in different solvents of varying polarities, ranging from chloroform (z=63.2) to methanol (Z=83.6) by ultraviolet spectroscopic methods. The low percentages of enol contents in formamide, dimethylformamide and dimethylsulphoxide, may be due to the formation of charge transfer complexes of these solvents with the diketones. Free energy of tautomerisation has also been calculated. The substituents on the phenyl group attached to the nitrogen have no effect on enolisation.  相似文献   

7.
《Analytical letters》2012,45(7-8):901-914
Abstract

A simple and sensitive spectrophotometric method for the assay of some cardio-vascular drugs is described. The method is based on the interaction of the drug and p-chloranilic acid (p-CA) to give a stable and intensively coloured ion-pair salt. The drugs used are quinidine sulphate, prenylamine lactate, dipyridamol, hydralazine hydrochloride, tolazoline hydrochloride and pindolol. The optimum experimental conditions for colour development have been studied. Conformity to Beer's law enabled the determination of these drugs in their pharmaceutical preparations. The assay results are in accord with the pharmacopoeal assay results.  相似文献   

8.
采用电化学方法,结合紫外-可见光谱法研究异鼠李素(ISOR)在碳糊电极上与DNA的作用机制,并通过天然DNA(fsDNA)和变性DNA(ssDNA)与异鼠李素的作用的不同,得出异鼠李素与DNA分子发生嵌插作用的结论,形成DNA-2[ISOR] 1 : 2型的超分子化合物,求得结合常数β=1.03×105 L/mol.因此ISOR有可能成为一种用于DNA分析测定的新型探针.  相似文献   

9.
The optical second harmonic generation (SHG) has been powerful for in-situ characterization of surface (interface) structures. In this paper, we describe applications of the SHG technique for structural characterization of monolayer assemblies of some amphiphilic dyes formed at the water surface. Previously, we reported the number of aliphatic tails of the amphiphilic ruthenium complexes profoundly affected the monolayer structures, as studied by the SHG technique.  相似文献   

10.
本文对巴比妥酸-NO-2-铁(Ⅱ)-CPB显色体系进行了研究,建立了一种测定巴比妥酸的分光光度法,该法巴比妥酸含量在1.0×10-6~2.0×10-5g/mL范围内符合比尔定律。方法简便、快速且具有良好的选择性及重现性,用于巴比妥类药物合成样中巴比妥酸的测定,回收率在90.2%~102.1%  相似文献   

11.
Aminobutyric acid, carbocisteine and levodopa are attributed to amino acid derivative agents, which are widely used as drugs for resuming brain cells, grume regulator and curing parkinsonism, respectively. Several methods have been reported for quantitati…  相似文献   

12.
偶氮类染料与蛋白质作用的分光光度研究   总被引:20,自引:0,他引:20  
李娜 《分析科学学报》1997,13(4):265-270
本文研究了阴离子偶氮染料在酸性条件下与蛋白质的作用,在最佳反应条件下制定了标准工作曲线,讨论了蛋白质变剂的作用以摩尔比法测定了蛎结合数。  相似文献   

13.
Based on the analysis of UV/Vis-and CD spectra of several cyanine dyes in - and -cyclodextrin a case is made for the aggregation of the dyes into oligomers. The criteria for this new type of aggregates are: (i) the appearance of a concentration and temperature dependent shoulder on the high energy side of the dimer band in the UV/Vis-spectra; (ii) two oppositely signed high intensity CD absorptions, one centered at the shoulder, the other at about the energy of the monomer absorption. Calculations based on coupled-oscillator theory support the contention that chiral dye aggregates are formed in the presence of cyclodextrins, most probably trimers and tetramers. From UV/Vis- and CD-data a helically twisted sandwich structure is suggested for these aggregates. In contrast to the reported inclusion complexes these aggregates must form — at least partly — outside the chiral host.  相似文献   

14.
The J-aggregation capability of meso-ethylsubstituted thiacarbocyanine (Dye 1 and Dye 2) and oxacarbocyanine (Dye 3) dyes was studied in poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) films and aqueous solutions, as well as in water. In water, Dye 1 and Dye 3 form J aggregates and dimers, whereas Dye 2 occurs mainly in the dimer form. The addition of PVA to an aqueous solution leads to deaggregation of J aggregates of Dye 1 and Dye 3 and dimers of Dye 1, Dye 2, and Dye 3. Unlike PVA, PVP stimulates the J aggregation of Dye 1 in aqueous solution, with the J aggregate yield depending on the ratio between the PVP monomer unit and dye concentrations. The J aggregation of Dye 1 and Dye 3 takes place in PVA films, whereas the J aggregates of only Dye 1 are formed in PVP films. The photostability of Dye 1 J aggregates in aqueous solutions strongly depends on the spectral region of irradiation and the presence of atmospheric oxygen. The photostability is appreciably lower in aerated solutions and substantially increases in PVA films.  相似文献   

15.
本文就冠醚菁染料及其重要中间体的合戍方法、冠醚菁染料的络合性能、光热稳定性和光谱增感性能的研究进行了系统的介绍与评述,同时反映了国内外有关冠醚化合物在感光材料中的应月以及冠醚菁染料在其他领域中的最新研究成果,显示了它们潜在的应用前景。  相似文献   

16.
Abstract

Ion-pair reversed phase HPLC was observed to give very good separations of 20 representative cosmetic dyes whilst numerical analysis of VIS spectra provided an efficient additional means of identification when similar retention times for different dyes were encountered. The results strongly suggest that a combination of HPLC and rapid scanning VIS spectrophotometry should be very promising, especially when on-line computing facilities are available.  相似文献   

17.
Novel monomethine 2a‐f , dimethine 4a‐f and tetramethine 6a‐h cyanine dyes were prepared as conjugated dyes. Such dyes incorporating coumarin and/or quinoline derivatives 1a‐d . These dyes were synthesized to study their spectral behavior, solvatochromism and biological activity. These dyes are characterized by elemental analysis, IR, 1H NMR and mass‐spectra.  相似文献   

18.
三波长分光光度法测定曙红墨水中的染料   总被引:1,自引:0,他引:1  
用三波长分光光度法测定了曙红墨水中的染料。墨水稀释液中的弱酸性红A在536,516,497nm处测定,酸性红G在608,546,453.5nm处测定。本法操作简便,结果准确。  相似文献   

19.
《Analytical letters》2012,45(8):1635-1644
ABSTRACT

The stepwise formation constants of Ce3+, Th4+ and UO2 2+ complexes with four azo compounds based on I-phenyl-2, 3-dimethylpyrazoline-5-one nucleus namely; 4-phenylazo- (2-hydroxy, 5-x) 1-pheny1-2, 3-dimethy1-pyrazoline-5-one, where x= H (1), OH (II), COOH (III) and NH2 (IV) have been determined potentiometrically at different temperatures and ionic strengths in 30% (v/v) ethanol-water solutions, then the thermodynamic parameters are calculated.

Negatives values of both ∠H and ∠G are obtained indicating the exothermic and spontaneous nature of complexation reactions, whereas positive values of ∠S show that entropy consideration favour complex formation. The study at different ionic strengths shows that an increase in the latter causes a decrese in the pK values. The azo compounds are also tested as new reagents for the spectrophotometric determination of Ce3+, Th4+ and UO2 2+ ions in synthetic and natural solutions by extensive investigation of the optimum conditions favoring the formation of colored complexes.  相似文献   

20.
Spectrophotometry was used to study the interaction of high-molecular polyacrylamide with cationic dyes: Methylene Blue, Acridine Yellow, and Toluidine Blue. Polyacrylamide samples were modified by alkaline hydrolysis. The optimum conditions of the formation of polyacrylamide–cationic dye adducts and their compositions were found. Simple procedures are proposed for the determination of the polymer. The relative standard deviation of the results of the determination of polyacrylamide in aqueous solutions is no higher than 6%.  相似文献   

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