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Titrimetric and spectrophotometric determination of doxycycline hyclate using bromate-bromide, methyl orange and indigo carmine  [PDF]
Pavagada Jagannathamurthy Ramesh,Kanakapura Basavaiah,Mysore Ranganath Divya,Nagaraju Rajendraprasad
Chemical Industry and Chemical Engineering Quarterly , 2010,
Abstract: One titrimetric and two indirect spectrophotometric methods are described for the determination of doxycycline hyclate (DCH) in bulk drug and in its formulations. The methods use bromate-bromide, methyl orange and indigo carmine as reagents. In titrimetry (method A), DCH is treated with a known excess of bromate- -bromide mixture in acid medium and the residual bromine is back titrated iodometrically after the reaction between DCH and in situ bromine is ensured to be complete. In spectrophotometric methods, the excess of bromine is estimated by treating with a fixed amount of either methyl orange (method B) or indigo carmine (method C) and measuring the change in absorbance either at 520 or 610 nm. Titrimetric method is applicable over 1-8 mg range and the calculations are based on a 1:2 (DCH:bromate) stoichiometric ratio. In spectrophotometry, the calibration graphs were found to be linear over 0.25-1.25 and 1.0-5.0 μg mL-1 for method B and C, respectively, with corresponding molar absorptivity values of 2.62×105 and 6.97×104 L mol-1 cm-1. The accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of DCH.
Simple and practicable methods for the determination of astemizole in pharmaceuticals using bromate-bromide and two dyes
Nagegowda, Paregowda;Basavaiah, Kanakapura;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000500022
Abstract: one titrimetric and two spectrophotometric methods, which are simple and sensitive, are described for the determination of astemizole (ast) in bulk drug and formulations. the methods use bromate-bromide mixture and two dyes, methyl orange and indigo carmine. in titrimetry (method a), astemizole is treated with a known excess of bromate-bromide mixture in acid medium and after the bromination reaction is ensured to be complete, the residual bromine is back-titrated iodometrically. in spectrophotometric methods, the excess of bromine is estimated by treating it with a fixed amount of either methyl orange (method b) or indigo carmine (method c) and measuring the change in absorbance either at 520 or 610 nm. in all the methods, the amount of bromate reacted corresponds to the drug content. titrimetric method is applicable over 4-16 mg range and the calculations are based on a 1:0.666 (ast: bromate) reacting ratio. in spectrophotometry, the calibration graph is found to be linear over 0.5-4.0 μg ml-1 (method b) and 1.25 12.5 μg ml-1 (method c) with molar absorptivity values of 6.6 x 104 l mol-1 cm-1 and 2.1 x 104 l mol-1 cm-1, respectively. the limits of detection and quantification are reported for methods b and c. the statistical evaluation of the methods was examined by determining intra-day and inter-day precision. the methods were applied to the determination of ast in tablets and syrups and the results were found to agree well with the label claim. the accuracy and reliability of the methods were further ascertained by parallel determination by a reference method and by calculating the student's t-value and f-value at the 95% confidence level, and by recovery studies using standard addition technique.
Spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs Using N-Bromosuccinimide and Indigo Carmine Dye  [PDF]
Mohamed A. El Hamd,Sayed M. Derayea,Osama H. Abdelmageed,Hassan F. Askal
International Journal of Spectroscopy , 2013, DOI: 10.1155/2013/243059
Abstract: Indirect spectrophotometric method is described for quantification of five of 1,4-dihydropyridine (1,4-DHP) drugs using N-bromosuccinimide (NBS) with the aid of indigo carmine (INC) dye. The method is based on addition of known excess of NBS to an acidified solution of 1,4-DHP drugs and determining the residual of NBS through its ability to bleach the colour of the used dye; the amount of NBS that reacted corresponded to the amount of drugs. Beer’s law is obeyed in the concentration range 1.25–13.00?μg/mL. Good correlation coefficients (0.998-0.999) were found between the absorbance values and the corresponding concentrations. Limits of detections ranged from 0.141 to 0.500?μg/mL. The proposed method was successfully applied to the analysis of dosage forms; percent of recoveries ranged from 97.31 to 99.46% without interference from any common excipients. The statistical comparison by Student’s t-test and variance ratio F-test showed no significant difference between the proposed and official or reported methods. 1. Introduction 1,4-DHP derivatives are vasodilators with a great selectivity for vascular smooth muscles; they are primarily used for treatment of some of cardiovascular diseases such as hypertension, angina, and cardiac arrhythmias. Recently, they were used for the treatment of other pathological states, such as seizures and cerebral ischemic disorders [1, 2]. Many analytical methods were developed for determination of 1,4-DHP drugs, namely, nifedipine (NIF), nicardipine (NIC), nimodipine (NIM), felodipine (FEL), and amlodipine (AML) (Figure 1), in their pharmaceutical formulations and in biological fluids, such as titrimetric methods [3, 4], spectrometric methods (spectrophotometry [5–13] or spectrofluorimetry [12, 14–20]), electrochemical methods [21–23], liquid chromatographic methods [24–28], and gas chromatographic methods [29–32]. Figure 1: Chemical structure of the investigated 1,4-DHP drugs. Classical spectrophotometric measurements and their applications are considered as a routine analytical method in most quality control laboratories. Subsequently, the aim of this study to develop a simple, sensitive, and cost-effective method for determination of these drugs in pure and dosage forms using spectrophotometric technique. The method utilized NBS-INC reagents (Figure 2) and their developed offer the advantage of simplicity, sensitivity, speed, accuracy, and precision without the need for costly equipment/chemicals. Figure 2: Chemical structure of the chemical reagents. 2. Experimental 2.1. Instrumentation Absorbance measurements were
Exploratory study on sequestration of some essential metals by indigo carmine food dye
Zanoni, Thalita Boldrin;Cardoso, Arnaldo Alves;Zanoni, Maria Valnice Boldrin;Ferreira, Antonio Aparecido Pupim;
Brazilian Journal of Pharmaceutical Sciences , 2010, DOI: 10.1590/S1984-82502010000400014
Abstract: indigo carmine forms a stable complex with different ions, and the stability constant of the complexes were evaluated as log k equal to 5.75; 5.00; 4.89 and 3.89 for complexes with cu(ii), ni(ii), co(ii) and zn(ii) ions, respectively, in 0.1 mol l-1 carbonate buffer solution at ph 10. the interaction between cu(ii) ions and indigo carmine (ic) in alkaline medium resulted in the formation of the cu2(ic) complex, measured by the spectrophotometric method, with a stoichiometric ratio between indigo carmine and metal ions of 2:1 (metal-ligand). the reported method has also been successfully tested for determination of copper in pharmaceutical compounds based on copper-gluconate without pre-treatment.
Effect of silica sources in nanoporous silica synthesis on releasing behavior of indigo carmine
Chanatip Samart,Chatchawan Sookman
Songklanakarin Journal of Science and Technology , 2009,
Abstract: Nanoporous silica was applied in controlled releasing experiments. Different physical properties of the nanoporous silica, related to variations of the silica sources, affected the releasing behaviour. Two different silica precursors in nanoporous silica synthesis were investigated, tetraethoxysilane and sodium silicate. The nanoporous silica, which was obtained by tetraethoxysilane, gave the highest surface area (800 m2/g) and pore volume (1.2 cc/g). On the other hand, the nanoporous silica obtaining from sodium silicate showed the largest pore size (9 nm). The nanoporous silica with larger pore volume can load a higher amount of indigo carmine, which resulted in a fast release due to the large driving force between the silicaparticle and media solution. However, the releasing rate was not only affected by the pore volume, but also by the interactionbetween the silanol groups on the silica surface and molecules of indigo carmine.
Photocatalytic Degradation of Indigo Carmine Dye Using Calcium Oxide  [PDF]
Kirana Devarahosahalli Veeranna,Madhu Theeta Lakshamaiah,Ramesh Thimmasandra Narayan
International Journal of Photochemistry , 2014, DOI: 10.1155/2014/530570
Abstract: Calcium oxide was used as photocatalyst for the degradation of indigo carmine dye solution in the visible, long UV, and short UV radiation. We have investigated the effectiveness of degradation of indigo carmine dye solution at pH 9 and 12 using calcium oxide with the particle size of 30–36?nm by varying the concentration, dose of adsorbent, and duration. It has been found that the degradation of indigo carmine dye is effective at pH = 9, when 0.12?g of calcium oxide was used. The nature of interaction between calcium oxide and indigo carmine dye was discussed. 1. Introduction The water bodies are continuously polluted due to the unscientific methods adopted by the chemical, textile, paper, and pulp industries, and so forth, during the discharge of toxic and hazardous chemicals [1–5]. Complexity of the dye molecules does not favour the natural process of degradation and also during certain instances incomplete degradation or transformation may generate carcinogenic byproducts [6–9]. Therefore, physical, chemical, and biological methods have been developed for the treatment of dye effluents from industries [10]. Precipitation, coagulation, floatation, and oxidizing agents have been used for the treatment of different types of dyes. Major disadvantages of chemical methods are that they require expensive chemicals and the products generated after dye treatment are also polluting in nature [11, 12]. Biological methods to degrade dyes include enzymes and microorganisms and are found to be effective but the difficulty is to scale up the process [13]. Membrane-filtration processes, electrodialysis, and adsorption involve physical processes which are cheaper compared to biological methods but the maintenance of membranes is expensive [14–16]. Electrochemical process, electrokinetic coagulation, irradiation with light, and photochemical oxidation have been employed for the removal of dye effluents [17]. Major limitations of the above methods are the operating cost, generation of byproducts, and the process of regeneration of the starting compounds which are difficult or tedious [10]. Therefore, degradation of dyes into its smaller fragments of less toxic organic compounds is one of the major challenges faced by scientists, technologists, and researchers across the world. Development of catalysts which can interact with sunlight and degrade the toxic dyes into its low molecular weight colourless and nontoxic fragments which can be discharged into the water bodies without affecting their physicochemical properties is the major objective. Photocatalytic degradation
New Sensitive Spectrophotometric Methods for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Bromate-Bromide,Methyl Orange and Indigo Carmine  [PDF]
K Basavaiah,U. R. Anil Kumar
Journal of Chemistry , 2006, DOI: 10.1155/2006/472186
Abstract:
Laccase isozymes of Pleurotus sajor-caju culture on husk and bran of black sticky rice and their potential on indigo carmine decolourisation
R Sarnthima, S Khammuang
African Journal of Biotechnology , 2008,
Abstract: Extracellular laccases of Pleurotus sajor-caju grown on solid state medium consisted of husk and bran of black sticky rice, were partially purified by DEAE–cellulose chromatography. These laccases could be separated into three groups: unboundLac and bound fractions (pool1Lac and pool2Lac). The optimum pH of these laccases was studied using ABTS as substrate. It was found that the pH optimum for unboundLac fell in the range of 3–5 and 3–4 for pool1Lac and pool2Lac. The indigo carmine decolourisation capacity was compared between unboundLac and pool2Lac. It was found that the optimal pH for indigo carmine decolourisation were 5 and 3 for unboundLac and pool2Lac, respectively. In the range of various dye concentrations tested, it was found that indigo carmine at 10 ìM with the enzyme activity of 0.01 U, gave the best dye decolourisation with 40.47% within 120 min for unboundLac and with 18.61% within 150 min for pool2Lac. High amount of enzyme used of these laccases might improve decolourisation ability.
Ozonation of Indigo Carmine Catalyzed with Fe-Pillared Clay  [PDF]
Miriam Bernal,Rubí Romero,Gabriela Roa,Carlos Barrera-Díaz,Teresa Torres-Blancas,Reyna Natividad
International Journal of Photoenergy , 2013, DOI: 10.1155/2013/918025
Abstract: The ozonation catalyzed by iron-pillared clays was studied. The degradation of dye indigo carmine (IC) was elected as test reaction. Fe-pillared clays were synthesized by employing hydrolyzed FeCl3 solutions and bentonite. The pillared structure was verified by XRD and by XPS the oxidation state of iron in the synthesized material was established to be +2. By atomic absorption the weight percentage of iron was determined to be 16. The reaction was conducted in a laboratory scale up-flow bubble column reactor. From the studied variables the best results were obtained with a particle size of 60 microns, , ozone flow of 0.045?L/min, and catalyst concentration of 100?mg/L. IC was completely degraded and degradation rate was found to be double when using Fe-PILCS than with ozone alone. DQO reduction was also significantly higher with catalyzed than with noncatalyzed ozonation. 1. Introduction A vast amount of water is employed by the textile industry. Because of the dyeing process, the produced wastewater contains strong color and this is reflected as well in a high chemical oxygen demand (COD). It has been estimated that 1–15% of the dye is lost during dyeing and finishing processes and is released into wastewater [1, 2]. Even small quantities (<0.005?mg?L?1) of dyes in water are unacceptable since the discharge of effluents containing reactive dyes into the environment can interfere with transmission of sunlight into flowing liquid [3]. This causes perturbations in aquatic life and the food web [4]. Thus, an effective and economical technique for removing dyes from textile wastewaters is needed [5]. In this sense, several conventional methods for treating dye effluents have been studied, such as photodegradation [6], adsorption [7], filtration [8], coagulation [9], and biological treatments [10]. However, due to the stability of the molecules of dyes some of these methods are not completely effective and/or viable. In recent years, water treatment based on the chemical oxidation of organic compounds by advanced oxidation processes (AOPs) like ozonation has drawn attention. Ozonation, which is effective, versatile, and environmentally sound, has been tested as a good method for color removal [11]. Ozone is a strong oxidant and reacts rapidly with most of organic compounds [12]. It oxidizes organic pollutants via two pathways: direct oxidation with ozone molecules and/or the generation of free-radical intermediates, such as the radical, which is a powerful, effective, and nonselective oxidizing agent [13, 14]. However, the degree and rate of oxidation by
Sm FeTaO Photocatalyst for Degradation of Indigo Carmine Dye under Solar Light Irradiation
Leticia M. Torres-Martínez,Miguel A. Ruiz-Gómez,M. Z. Figueroa-Torres,Isaías Juárez-Ramírez,Edgar Moctezuma
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/939608
Abstract: This paper is focused to study Sm2FeTaO7 pyrochlore-type compound as solar photocatalyst for the degradation of indigo carmine dye in aqueous solution. Sm2FeTaO7 was synthesized by using conventional solid state reaction and sol-gel method. X-ray diffraction results indicated that Sm2FeTaO7 exhibit a monoclinic crystal structure. By scanning electron microscopy analysis, it was observed that sol-gel material presents particle size of around 150 nm. The specific surface area and energy bandgap values were 12 m2 g−1 and 2.0 eV, respectively. The photocatalytic results showed that indigo carmine molecule can be degraded under solar light irradiation using the synthesized materials, sol-gel photocatalyst was 8 times more active than solid state. On the other hand, when Sm2FeTaO7 was impregnated with CuO as cocatalyst the photocatalytic activity was increased because CuO acts as electron trap decreasing electron-hole pair recombination rates.
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