Enrichment Factor
Mostrando 1-12 de 161 artigos, teses e dissertações.
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1. Development of a Disposable Pipette Extraction Method Using Coffee Silverskin as an Adsorbent for Chromium Determination in Wastewater Samples by Solid Phase Extraction
A procedure using disposable pipette tips adapted for solid-phase extraction, known as DPX SPE, was used as an alternative way for the chromium determination in wastewater samples. DPX-SPE consists of a device which allows a dynamic contact between the sample and the solid-phase. A residue obtained from the processing of coffee beans, denominate coffee silve
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. 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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3. Characterization, Source Apportionment and Health Risk Assessment of PM2.5 for a Rural Classroom in the Amazon: A Case Study
Classrooms are microenvironments in which children and teenagers may be exposed to fine particulate matter (PM2.5). Iranduba is a rural city in the Amazon region close to many brick kilns and road with high traffic levels. In this study, indoor and outdoor PM2.5 levels were measured in a classroom in Iranduba, and the PM2.5 exposure effects on student’s he
J. Braz. Chem. Soc.. Publicado em: 2021-02
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4. DETERMINATION OF THE PESTICIDES IN WATER USED IN THE CULTURE AND PROCESSING OF POTATOES
The contamination of water bodies by pesticide residues through direct flow, leaching and other methods has motivated the development of analytical methods for the determination of these compounds in water. A vortex-assisted liquid-liquid microextraction method followed by gas chromatography coupled to mass spectrometry for the determination of anilazine, li
Quím. Nova. Publicado em: 2020-09
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5. Elemental Composition of Particulate Matter in the Southeastern Brazilian Ceramic Pole by Synchrotron Radiation X-ray Fluorescence Technique (SR-XRF)
In the present study, the elemental content of the particulate matter PM2.5 (particulate matter with diameters lower than 2.5 µm) and PM10 (particulate matter with diameters lower than 10 µm) of the Brazilian city of Rio Claro (SP) were analyzed by synchrotron radiation X-ray fluorescence (SR-XRF) in the Brazilian Synchrotron Light Laboratory (LNLS). A fra
J. Braz. Chem. Soc.. Publicado em: 2020-06
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6. Application of a Novel Ion-Imprinted Polymer to the Separation of Traces of CdII Ions in Natural Water: Optimization by Box-Behnken Design
This study describes the preparation of a novel ion-imprinted polymer (IIP) to apply pre-concentration of cadmium ions in water samples of the Pontal Bay in Ilhéus, Brazil. First, cadmium ion was complexed with 2-(2-thiazolylazo)-p-cresol (TAC). Subsequently, there was the polymerization using ethylene glycol dimethacrylate and methacrylic acid monomers alo
J. Braz. Chem. Soc.. Publicado em: 2019-04
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7. Synthesis of Chelating Agent Free-Solid Phase Extractor (CAF-SPE) Based on New SiO2/Al2O3/SnO2 Ternary Oxide and Application for Online Preconcentration of Pb2+ Coupled with FAAS
A new online solid phase preconcentration method using the new SiO2/Al2O3/SnO2 ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb2+ determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized by Fourie
J. Braz. Chem. Soc.. Publicado em: 2018-06
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8. Prevalence of Streptococcus agalactiae colonization in pregnant women from the 18th Health Region of Paraná State
ABSTRACT Introduction The aim of this study was to determine the prevalence of GBS colonization in pregnant women in a public health service. Methods A study of 496 pregnant women at 35-37 gestational weeks was conducted from September 2011 to March 2014 in 21 municipalities of the 18th Health Region of Paraná State. Vaginal and anorectal samples of eac
Rev. Inst. Med. trop. S. Paulo. Publicado em: 15/02/2018
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9. DLLME-GC/ECD Method for the Residual Analysis of Parathion-Methyl and its Application in the Study of the UV-Photodegradation Process
A new method has been developed to determine trace levels of organophosphorus pesticide parathion-methyl in water samples by using dispersive liquid-liquid microextraction (DLLME), followed by gas chromatograph coupled with electron capture detector (GC/ECD) analysis. The optimized and validated method showed high extraction recovery (101.1%), high enrichmen
J. Braz. Chem. Soc.. Publicado em: 2017-11
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10. High fire temperature changes soil aggregate stability in slash-and-burn agricultural systems
ABSTRACT Fire is a key controlling factor in ecosystem dynamics worldwide, especially, in tropical areas under slash-and-burn agricultural systems. Farmers use fire as a tool to clean the land, and benefit from nutrient enrichment from ash-soil heating. However, fire can cause some detrimental effects on soil systems, such as organic carbon depletion, increa
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-04
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11. Evaluation of Major and Trace Elements in Medicinal Plants
This study presents the elemental concentration results obtained from 59 medicinal plants used in Brazil, determined by instrumental neutron activation analysis (INAA), inductively coupled plasma-optical emission spectrometry (ICP OES) and cold vapor atomic absorption spectrometry (CV AAS). The selected plant species were chosen from the Brazilian National A
J. Braz. Chem. Soc.. Publicado em: 2016-12
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12. Decanoic Acid Reverse Micelle-Based Coacervates for Microextraction of Silver in Natural Waters Prior to Flame Atomic Absorption Spectrometry Determination
In the present work, a novel, simple, and efficient method for the determination of silver in natural water samples was developed. The method is based on the extraction of silver with coacervate made up of decanoic acid reverse micelles and the subsequent determination by flame atomic absorption spectrometry (FAAS). Dithizone was used as a chelating agent. T
J. Braz. Chem. Soc.. Publicado em: 2016-11