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Search Results: 1 - 10 of 798 matches for " Spectrophotometry "
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In Vivo Emulsification Analysis of 1000 cs and 5000 cs Silicone Oil after Rhegmatogenous Retinal Detachment Vitrectomy Surgery  [PDF]
Arief Kartasasmita, Widi Kusdiono, Rova Virgana, Shanti Boesorie
Open Journal of Ophthalmology (OJOph) , 2017, DOI: 10.4236/ojoph.2017.74031
Purpose: To compare in vivo emulsification of silicone oil 1000 and 5000 centistokes (cs) after retinal detachment surgery. Design: Comparative non-interventional Retrospective study. Methods: Silicone oils from patients who underwent retinal detachment surgery were investigated using Spectrophotometer UV-Vis. Spectroscopically changes determine emulsification with the time of tamponade, inflammation, patients age and severity of retinal detachment. Results: We found significant difference on absorbance (p = 0.004) between used 1000 Centi stoke (cs) silicon oil (average wave length 2.51 nm; SD: 1.575 nm) and used 5000 cs silicon oil (average wave length 0.910 nm; SD: 0.564 nm). Conclusions: In vivo emulsification was higher in silicone oil 1000 compared to 5000 cs silicone oil after vitreoretinal tamponade 8 - 12 weeks due to retinal detachment surgery. Emulsification related to higher absorbance and lower transmittance in 1000 cs silicone oil. Inflammation may become a factor affecting this condition.
Fourth Derivative Spectrophotometric Method for the Determination of Fungicide Maneb Using Sodium Molybdate  [PDF]
Manpreet Kaur, Ashok Kumar Malik, Baldev Singh
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.22018
Abstract: A highly sensitive fourth derivative spectrophotometric method is presented for the residue analysis of ethylenebis dithiocarbamate fungicide Maneb. The fungicide maneb forms a blue complex with sodium molybdate on heating which is studied spectrophotometrically. The method has been successfully applied to maneb determination in wheat grains and soft drinks with high recoveries. The analytical sensitivity of the present method has been found to be 0.0011 μg/mL.
Analytical and Stability Studies on Medical Cosmetics  [PDF]
Manal I. Eid, Mary E. K. Wahba
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.33037
Abstract: Two simple and sensitive spectrofluorimetric (method Ι) and spectrophotometric (method ΙΙ) methods have been developed for the determination of some chloride containing toothpastes and panthenol-containing cosmetic preparations respectively. Method Ι is based on quantitative fluorescence quenching of (terbium-salicylate-hexamine ternary complex) by fluoride which could be measured at λem/λex of 547 nm/322 nm. The ΔF-concentration plot was rectilinear over the concentration range of 0.5 - 20 μg/ml. Method ΙΙ depends reaction of panthenol with nitrobenzoxadiazole chloride (NBD-Cl) and measuring the absorbance of the resultant product at 480 nm. The absorbance-concentration plot was rectilinear over the concentration range of 2 - 20 μg/ml.
Analysis of the interaction between [Ru(phenanthroline)3]2+ and bovine serum albumin  [PDF]
Laura Luzuriaga, María Fernanda Cerdá
Advances in Biological Chemistry (ABC) , 2012, DOI: 10.4236/abc.2012.23033
Abstract: The interaction of compounds with potential use as pharmaceutical with a carrier protein as serum albumin is of great importance in their biodistribution. Albumin offers different sites for binding metallic compounds. Using a combination of spectropho-tometric and electrochemical techniques, the interaction between [Ru(phen)3]Cl2 (phen = phenantroline) and bovine serum albumin was evaluated. In particular, it was possible to calculate an apparent binding constant (Kb) of 4.4 × 103 (for concentrations expressed in M) for the main interaction site of the protein. A number of ca. 40 molecules of Ru-phen per molecule of BSA under saturation conditions, and a positive cooperative behavior towards association from the protein were found.
Detection of Sulfite Content in Agricultural Products Logistics Technology Research—Taking an Example of Mushroom  [PDF]
Wei Wang
Open Journal of Social Sciences (JSS) , 2016, DOI: 10.4236/jss.2016.46017
Abstract: In today’s real life, from the perspective of the logistics quality of agricultural products, there are many problems are paid attention by social people, such as mushroom. Mushroom products in China’s exports have repeatedly been reported because of containing more sulfur dioxide in recent years. Also the dried mushroom exports were notified by nine times. Mushroom in the life is one of the people’s favorite foods, so food healthy problem is to let the consumer concern it. This article explores a new method by pararosaniline hydrochloric spectrophotometry for determination of sulfur dioxide in mushroom, in the instrument detection and method research. This experiment uses the colorimetric method that is in charge of the UV spectrophotometer instrument. Finally this article puts forward the feasibility of this method. In the determination of mushrooms, laboratory reagents are used with non-toxic mercury. It reaches the national standard and it has practical feasibility.
Simple, Inexpensive and Ecologically Friendly Derivative Spectrophotometric Fluconazole Assay from Nail Lacquer Formulations  [PDF]
Alisa Elezovi?, Amar Elezovi?, Sabira Had?ovi?
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.22012
Abstract: Nail lacquers represent new drug form specifically designed to treat infected nail plate. They are complex organic solutions with specific assaying problems due to the high content of the polymer and plasticizer. Furthermore, there is a lack of assaying methods of active substances from this type of formulations in scientific literature. We developed derivative UV-spectrophotometric method for determination of fluconazole content in antifungal nail lacquer formulations. The method was validated for specificity, linearity, precision (repeatability), intermediate precision and accuracy (recovery). The method is specific, linear in the range of 99.53 - 497.65 μg/ml, precise and showed good recovery (98.79% - 101.77% from all six developed formulations). Besides, it is inexpensive, simple and nontoxic, i.e. ecologically acceptable. This method can be used for assaying fluconazole from this type of formulations.
Spectophotometric method for determination of certain cephalosporins using 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl)  [PDF]
Azza H. Rageh, Salwa R. El-Shaboury, Gamal A. Saleh, Fardous A. Mohamed
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.28104
Abstract: A simple, accurate and precise spectrophotometric method has been proposed for the determination of eleven cephalosporins, namely; cefaclor monohydrate, cefadroxil monohydrate, cefalexin anhydrous, cefradine anhydrous, cefotaxime sodium, cefoperazone sodium, ceftriaxone sodium, ceftazidime penthydrate, cefazolin sodium, cefixime and cefpodoxime pro- xetil in bulk drug and in pharmaceutical formulations. The method depends on hydrolysis of the studied drugs using 0.5M NaOH at 100°C and subsequent reaction of the formed sulfide ions with NBD-Cl (4-chloro-7-nitrobenzo-2-oxa-1, 3-diazole) to form a yellow-colored chromogen measured at 390 nm. Different variables affecting the reaction (e.g. NaOH concentration, hydrolysis time, NBD-Cl concentration and diluting solvent) were studied and optimized. Under the optimum conditions, linear relationships with good correlation coefficients (0.9990- 0.9999) were found in the range of 5-160 μg mL-1 for all studied drugs. The limits of assay detection and quantitiation ranged from 0.289 to 5.867 and from 0.878 to 17.778 μg mL-1; respectively. The accuracy and precision of the proposed method were satisfactory. The method was successfully applied for analysis of the studied drugs in their pharmaceutical formulations and the recovery percentages ranged from 96.6 to 103.5%.
Spectrophotometric Determination of Kelthane in Environmental Samples  [PDF]
Etesh K. Janghel, Y. Pervez
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.26083
Abstract: Sensitive spectrophotometric method for determination of kelthane in sub parts per million level is described, which is based on Fujiwara reaction. Kelthane on alkaline hydrolysis gives chloroform, which can be reacted with pyridine to produce red colour. The colour is discharged by addition of glacial acetic acid. Then Benzidine (4,4’-Bianiline) reagent is added due to which a yellowish-red colour is formed which has an absorption maximum at 490nm. Beer’s law is obeyed in the range of 3.3 - 26.0 µg (0.13 - 1.04 ppm) of Kelthane per 25ml of final solution. The molar absorptivity and Sandell’s sensitivity were found to be 4.32 × 105 L?mol–1?cm–1 and 0.022 µg?cm–2 respectively. The method is found to be free from interferences of other organochlorine pesticides and various co-pollutants and can be successfully applied for the determination of kelthane in environmental samples.
Quantitative Determination of Fluoxetine in Pharmaceuticals and Plasma Samples Using Bromatometric Method  [PDF]
Jasmin Shah, Muhammad Rasul Jan, Muhammad Naeem Khan, Sadaf Durrani
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.312109
Abstract: Asensitive and simple spectrophotometric method has been developed for quantitative determination of fluoxetine using bromatometric method. The method is based on the addition of measured excess amount of bromate-bromide mixture to fluoxetine in hydrochloric acid medium. The residual bromine was determined by reacting with a fixed amount ofmethyl orange and absorbance was measured at 505 nm. The amount of bromine reacted corresponds to the amount of fluoxetine. Linear relationship between absorbance and fluoxetine concentration was found and Beer’s law was obeyed in the concentration range of 0.4 - 12 μg·mL–1. The molar absorptivity was found to be 3.8 × 104 L·mol–1·cm–1. The limit of detection and limit of quantification was calculated and found to be 0.32 μg·mL–1 and 1.0 μg·mL–1respectively. The common excipients were investigated for their interferences effect in the assay. The validity of the developed method was checked through recoveries studies and successfully applied to the determination of fluoxetine in bulk powder, pharmaceutical formulations and spiked human plasma samples. The percent recoveries were found to be in the range of 97.0% - 101.0% for pharmaceutical formulations and from 97.0% - 99.0% for spiked human plasma.
3D Fluorescence Characterization of Synthetic Organic Dyes—Effect of pH  [PDF]
Leonard J. Soltzberg, Sarah Flynn, Vera Kirch, Richard Newman
American Journal of Analytical Chemistry (AJAC) , 2013, DOI: 10.4236/ajac.2013.410067

The fingerprint character and high sensitivity of 3D UV-vis fluorescence spectra offer special advantages for identification of dyes in a museum or forensic setting. However, the extraction process is likely to affect the pH of the medium and, in some cases, may alter the dye itself. We report a study of 65 dyes extracted from wool fibers that are part of the Schweppe Collection of Important Synthetic Dyes. The 3D fluorescence spectra of the dye extracts at pH 1 and pH 14 are compared with the same dyes from the Schweppe solution library, run under the same conditions, as well as with the 3D fluorescence spectra of the dyes taken directly from the solution library without pH control. This analysis leads to guidelines for the use of such spectra in identifying unknown dye samples.

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