Analytical Determination
Mostrando 1-12 de 781 artigos, teses e dissertações.
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1. 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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2. Simultaneous GC-NCI-MS Determination of Persistent Organic Pollutants and Current-Use Pesticides in Breast Milk Samples
To preserve human health, persistent organic pollutants (POPs) and current-use pesticides (CUPs) should be monitored in fatty tissues, including breast milk. Therefore, this study aimed to optimize sample preparation conditions using a 32 factorial design for the determination of POPs and CUPs by gas chromatography coupled to mass spectrometry with negative
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Thermal Infrared Enthalpimetry Method for the Determination of Hypochlorite in Bleaching Solutions
Thermal infrared enthalpimetry (TIE) was used for hypochlorite determination in commercial hypochlorite-based bleaching solutions. Experimental parameters were evaluated for the reaction with a hydrogen peroxide solution. The most relevant conditions were 5% H2O2 (m/m) solution, stirring speed of 250 rpm, dispensing rate of 0.57 mL s-1, and 10 s after reacti
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Response Factor in GC-FID Methyl Ester Analysis in Several Biodiesels: A Comparative Study of the EN 14103:2011 and ABNT 15764:2015 Methods versus a Proposed GC-FID Procedure for Individual Ester Determination
A gas chromatography method with a flame ionization detector enabled by relative response factor was developed to determine the individual and the total content of esters in biodiesel. This method accounts for different response factors of the detector for a homologous series of esters that may be present in biodiesel. In this way, the determination of the t
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. A Green Analytical Method Using Polyurethane Foam for The Extraction and Determination of Lauryl Ether Sulfate in Personal Care Hygiene Products
A green methodology was developed for the extraction and determination of lauryl ether sulfate in raw materials and commercial liquid soap and shower gel samples. The method avoids the use of organic solvents, offering a simple, cheap, and safe analysis. The methodology is based on the sorption of an ionic pair consisting of a cationic dye and an anionic sur
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. A Simple, Rapid, and Reliable Titrimetric Method for the Determination of Glycerol at Low Concentration
Glycerol can be determined in several products by various analytical techniques. Titrimetric ones have stood out for their low cost, being recommended as standards. However, reliable, simple, fast, and green methods with low quantification limits are still needed. Titration of glycerol is based on its oxidation by periodate (Malaprade reaction) producing for
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. Development and Validation of a Rapid and Reliable HPLC-FLD Method for the Quantification of Ciprofloxacin and Enrofloxacin Residues in Zea mays
The accumulation of antibiotics by plants is a currently concern associated to yield reduction and transference of antibiotic residues along the food web. Maize is a staple food in many parts of the world; it is also considered an important ingredient in animal nutrition. Considering the lack of validated analytical methods for the analysis of ciprofloxacin
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. A Rational Procedure to Increase Selectivity in the Determination of an Elicitor as Salicylic Acid in Polygala Extracts Using Capillary Electrophoresis
Considering the economic potential of secondary metabolites, researches have been focusing several strategies in order to explore and enhance the accumulation of these metabolites in plant matrices in a broad context. One of those strategies is the development of suitable methodologies for the determination of some elicitors, such as salicylic acid (SA). Sin
Journal of the Brazilian Chemical Society. Publicado em: 2022
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9. ANALYSIS OF BENZODIAZEPINES IN PLASMA SAMPLES BY DLLME AND LC-DAD: CRITICAL ASPECTS, FLAWS AND ISSUES ENCOUNTERED - A DISCUSSION
Dispersive liquid-liquid microextraction (DLLME) is a fast and simple technique and applicable procedure for the analysis of xenobiotics in different biological matrices. We have developed a DLLME method for the determination of benzodiazepines in plasma samples using liquid chromatography-diode-array detection (LC-DAD). During method validation, relative st
Química Nova. Publicado em: 2022
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10. Use of Direct Aqueous Injection and Solid Phase Extraction Coupled with Hydrophilic Interaction Chromatography to Analyze Haloacetic Acids in Drinking Water Samples
In this study, two analytical methods were evaluated to determine haloacetic acids (HAAs) in drinking water samples. Direct aqueous injection (DAI) and solid phase extraction (SPE) were evaluated and determination was performed by liquid chromatography tandem mass spectrometry (LC-MS/MS) with a hydrophilic interaction chromatography (HILIC) analytical column
Journal of the Brazilian Chemical Society. Publicado em: 2022
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11. Preparation of Silicon Oxycarbide (SiCO) Ceramics from Different Polymer Architectures and Assessment on the Performance as Electrodic Materials for Voltammetric Sensing of Antioxidant Phenolic Compounds
Silicon oxycarbide (SiCO) ceramics obtained from polymer pyrolysis and with varied carbon contents were prepared and evaluated as new electrodic materials for sensing of tert butylhydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants. Three polymers were synthesized varying molecular architecture and aromatic carbon groups, followed by pyrolysi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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12. Validation and Application of a Methodology for Quantifying Levels of Parabens in Sports Supplements from Brazil Using Liquid Chromatography-Mass Spectrometry
Although parabens have been reported to be used as antimicrobial preservatives in personal care products, pharmaceuticals, and foodstuffs, little is known about the occurrence of these compounds in sports supplements. In this study, a simple, fast and sensitive liquid chromatography tandem mass spectrometry method for simultaneous determination of five commo
Journal of the Brazilian Chemical Society. Publicado em: 2022