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Mostrando 1-12 de 684 artigos, teses e dissertações.
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1. Carbon Dots from Pilosocereus gounellei for Fluorimetric Determination of Tannin in Tea Using a Flow-Batch System
In this study, xiquexique (Pilosocereus gounellei) native endemic cactus from the Brazilian semiarid was used for the first time as a natural carbon source (“green precursor”) for the synthesis of highly fluorescent carbon dots (CDs). These CDs were successfully used to develop a fast, low-cost, eco-friendly fluorescence method for the determination of t
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. 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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3. New Europium(III)-TTA Complex Containing 2-Pyrrolidone as Coligand to Application as Luminescent Sensor: PbII and Ethanol in Gasoline
This work describes the synthesis and application of an europium(III) complex, [Eu(TTA)3(2-pyr) (H2O)], containing 2-thenoyltrifuoroacetonate (TTA) and 2-pyrrolidone (2-pyr) as ligands, obtained as white solid and soluble in ethanol. In solution, the complex showed red emission, characteristic of the EuIII emission in the solid state (λexc = 375 nm and λem
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. DETERMINATION OF TOTAL AND BIOACCESSIBLE ELEMENTS IN TEMPORARY ADHESIVE TATTOOS USED BY CHILDREN AND ADULTS
The presence of bioaccessible potentially-toxic elements in five different brands of temporary tattoos (packaged with bubble gums) aimed at children and three product brands used by young and adult audiences were analyzed in accordance with the Brazilian Organization of Technical Standards (ABNT) and International Organization for Standardization (ISO) for t
Química Nova. Publicado em: 2022
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5. A Colorimetric and Fluorescent Dual-Signal Sensor for Detecting Lipase Activity Based on Inner Filter Effect
We developed a colorimetric and fluorescence dual-signal sensor for detecting lipase activity based on methyl thioglycolate (MT) functionalized gold nanoparticles (MT-AuNPs) and CdS quantum dots (CdS QDs). It is the first time that was developed a dual-signal sensing strategy for lipase activity based on the inner-filter effect (IFE) between MT-AuNPs and CdS
Journal of the Brazilian Chemical Society. Publicado em: 2022
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6. 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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7. Simultaneous Quantification of Amorphous and Crystalline Valsartan in Tablets Using Raman Spectroscopy and Chemometrics Tools
Valsartan is an antihypertensive active pharmaceutical ingredient (API), it is used in the amorphous state in the commercial products. As amorphous materials are metastable, amorphous valsartan can crystallize to valsartan E, promoting changes in the dissolution and bioavailability of the drug. Tablets containing metastable forms of APIs need special conditi
Journal of the Brazilian Chemical Society. Publicado em: 2022
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8. Dispersive Solid-Phase Extraction Using 3-Mercaptopropyltrimethoxysilane Functionalized Magnetic MWCNT-Based Nanocomposite for Selective and Efficient Preconcentration of Pb2+ with FAAS Determination
A novel nanocomposite based on magnetic multiwalled carbon nanotubes coated with SiO2 and functionalized with 3-mercaptopropyltrimethoxysilane (3-MPTMS) was prepared for the efficient extraction and quantification of lead ions from water samples. The adsorption capacity of this adsorbent could reach 1.995 mg g-1 Pb2+ in an equilibrium time of 30 min. Under o
Journal of the Brazilian Chemical Society. Publicado em: 2022
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9. Eco-friendly multivariant green analytical technique for the estimation of ketoconazole by UV spectroscopy in bulk and cream formulation
The pharmaceutical industries are focusing on Green Analytical Chemistry principles like miniaturization, eco-friendly solvent usage, waste recycling, and analyst safety for sustainable results. A simple, eco-friendly sensitive and effective extraction and multivariant green analytical method to estimate ketoconazole in bulk and cream formulation were develo
Química Nova. Publicado em: 2022
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10. Innovative gas chromatographic determination of formaldehyde by miniaturized extraction and on-fiber derivatization, via SPME and SPME Arrow
Formaldehyde (FA) is a carbonyl compound, ubiquitous in the environment and among the most widespread pollutants: it has exhibited toxic properties and is classified as a human carcinogen. FA is released from several sources, both temporary (e.g., combustion processes) and permanent (e.g., building products). This work proposes an innovative fully-automated
Química Nova. Publicado em: 2022
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11. A novel fluorescence sensor for the detection of chloride ion in artificial sweat and environmental water with nitrogen-doped graphene quantum dots
A new fluorescent detection route for chloride ion was designed with Nitrogen-doped graphene quantum dots (N-GQDs), which were prepared by a traditional hydrothermal method with citric acid as carbon source and urea as nitrogen source. The prepared N-GQDs solution was light yellow, and the freeze-dried solid was black. It emitted blue light under ultraviolet
Química Nova. Publicado em: 2022
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12. Determination of Ethyl Carbamate in Commercial Sweetened Sugar Cane Spirit by ESI-MS/MS Using Modified QuEChERS and 18-Crown-6/Trifluoroacetic Acid Spiking Additives
A fast, sensitive, and selective direct injection electrospray tandem mass spectrometry (DI ESI MS/MS) method that is able to quantify ethyl carbamate in commercial sweetened sugar cane spirit is described. The preparation method uses a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) with potassium carbonate added to sweetened sugar cane
Journal of the Brazilian Chemical Society. Publicado em: 2022