Spectrophotometric
Mostrando 1-12 de 800 artigos, teses e dissertações.
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1. Simple Spectrophotometric Determination of Iron in Diesel Oil after Sample Preparation Employing Extraction Induced by Emulsion Breaking
This work reports the development of a simple and fast method for the spectrophotometric determination of Fe in diesel oil using the classic reaction with 1,10-phenanthroline after its extraction induced by emulsion breaking (EIEB). The extraction parameters of EIEB were optimized (concentration of HNO3 and Triton X-100® in the emulsifying solution) as well
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Assessment of dynamic thiol-disulfide homeostasis in patients with lipoid proteinosis (Urbach-Wiethe syndrome)
SUMMARY OBJECTIVE: Lipoid proteinosis is a rare autosomal recessive genetic dermatological disease that occurs due to the accumulation of hyaline material in the skin and mucous membranes. This study aimed to investigate whether dynamic thiol-disulfide homeostasis is a new marker of oxidative stress in patients suffering from lipoid proteinosis. METHODS: T
Revista da Associação Médica Brasileira. Publicado em: 2022
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3. Oxidative Stress and Changes of Important Metabolic Gene Expressions as a Potential Biomarker in the Diagnosis of Atherosclerosis in Leukocytes
ABSTRACT Introduction: Presenilin 1 (PSEN1), catalase (CAT), glutathione-S-transferase (GST) and paraoxonase 1 (PON1) play a vital role in prediction, diagnosis and therapy of metabolic disorders. Methods: Metabolic enzyme activities and lipid peroxidation in serum of cerebrovascular diseases (CVD) and coronary artery diseases were measured by spectrophoto
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
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4. DEVELOPMENT AND OPTIMIZATION OF A SPECTROPHOTOMETRIC METHOD WITH CLOUD POINT EXTRACTION FOR DETERMINATION OF GADOLINIUM
This work describes a simple, sensible, and low-cost analytical method, based on cloud-point extraction (CPE) of the surfactant (1,1,3,3-Tetramethylbutyl)phenyl-polyethylene glycol (Triton X-114), for the efficient extraction and sensible determination of gadolinium after its complexation with 1-(2-pyridylazo)-2-naphthol (PAN) and subsequent determination by
Química Nova. Publicado em: 2022
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5. Determination of carrageenan in jellies with new methylene blue dye using spectrophotometry, smartphone-based colorimetry and spectrophotometric titration
Abstract Carrageenan is a seaweed polysaccharide widely used as a food gelling and thickening agent. The New Methylene Blue dye was tested as an analytical reagent for the quantification of carrageenan in commercial jelly samples. The main spectral peaks of the dye decrease with increasing carrageenan-to-dye molar ratio up to 1. Three analytical procedures w
Food Sci. Technol. Publicado em: 2021-06
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6. OTIMIZAÇÃO E VALIDAÇÃO DE MÉTODO ENZIMÁTICO SEMIQUANTITATIVO SIMPLES E DE BAIXO CUSTO PARA A BUSCA DE INIBIDORES DE CISTEINO PROTEASES
Cysteine proteases are an important class of enzymes involved in several essential biological processes. For this reason, these enzymes are important therapeutic targets, and therefore can be used in enzymatic assays for the search of hits. The most widely used methods in the search of enzyme inhibitors are spectrophotometric, however they have relatively hi
Quím. Nova. Publicado em: 2021-04
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7. UPLC-MS/MS and Dushman reaction based spectrophotometric method for determination of Ceftazidime, an antibiotic, in medicinal formulation
ABSTRACT: Two analytical methods were developed, one utilizing sensitive UPLC-MS/MS method while other being the spectrophotometric method exploiting the Dushman reaction. Both methods were validated based on ICH guidelines and were successfully applied to quantitate the drug in marketed formulation. UPLC-MS/MS method responded linearly in the range of 1.6 �
Food Sci. Technol. Publicado em: 2021-03
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8. Spectrophotometric Determination of Allura Red AC and Tartrazine in Food Products Using Hydrophobic Deep Eutectic Solvents as an Environmentally Sustainable Micro-Extractor
This paper reports the application of hydrophobic deep eutectic solvents (HDES) as an environmentally friendly alternative for liquid-phase microextraction (LPME) of Allura Red AC and Tartrazine in food products and the spectrophotometric determination of these analytes. The HDES used in this work were prepared by mixing octanoic acid (OctAc) or decanoic aci
J. Braz. Chem. Soc.. Publicado em: 2021-03
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9. DETERMINAÇÃO DE FÓSFORO EM PALEOSSEDIMENTOS EMPREGANDO ESPECTROMETRIA DE FLUORESCÊNCIA DE RAIOS-X PORTÁTIL
Phosphorus (P) is an important chemical marker of the past human presence, because, besides indicates the localization of possible archaeological sites, also, contributes to clarify doubts regarding to origin, duration and to specific functions that were developed in them. The present study aimed to obtain a simple, accurate, fast and non-destructible analyt
Quím. Nova. Publicado em: 2021-02
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10. Total phenolic acids and flavonoid contents determination in Yemeni honey of various floral sources: Folin-Ciocalteu and spectrophotometric approach
Abstract Twenty-nine Yemeni honey samples were analyzed to determine total phenolic and flavonoid contents using Folin-Ciocalteu and spectrophotometric technique. These tested honey samples were collected from different regions corresponding to various floral species: jujube, cactus and multifloral plants. Folin-Ciocalteu method was adopted for the analysis
Food Sci. Technol. Publicado em: 2020-12
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11. RAPID DETECTION OF VITAMIN C CONTENT IN FRUITS AND VEGETABLES USING A DIGITAL CAMERA AND COLOR REACTION
In this study, we propose a novel method to determine the vitamin C content in fruits and vegetables. The proposed method exploits the image and data processing abilities of computers by coupling a digital camera and a color reaction. An image acquisition device was developed to collect the image information of the solution to be measured after the color rea
Quím. Nova. Publicado em: 2020-12
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12. Development of a First-Order Derivative UV Spectrophotometric Method for the Assay and Solubility Evaluation of Lamotrigine and Nicotinamide Cocrystals
Pharmaceutical cocrystals are composed of a drug and a coformer and are currently gaining attention due to their possibility of improving drug solubility. Quantitative determination of cocrystals is usually carried out by liquid chromatography method, but an alternative for the same is derivative UV spectrophotometry. Cocrystals of lamotrigine (LAM) were for
J. Braz. Chem. Soc.. Publicado em: 2020-12