Doehlert
Mostrando 1-12 de 52 artigos, teses e dissertações.
-
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
-
2. Development of Analytical Method for Determination of Inorganic Constituents in Powder Refreshment Using Dilute Mineral Acids and Detection by ICP OES
An analytical method for multi-elementary determination in powder refreshment, based on sample digestion using dilute mineral acids and detection by inductively plasma coupled optical emission spectrometry (ICP OES) is proposed. Chemometric tools, such as fractional factorial design and principal component analysis (PCA) and hierarchical cluster analysis (HC
J. Braz. Chem. Soc.. Publicado em: 2021-07
-
3. A SIMPLE GREEN REDUCTION STRATEGY TO SUBSTITUTE CADMIUM IN ANALYTICAL REDUCTION OF NITRATE IN GRIESS–ILOSVAY METHOD
Nitrate is an abundant ion that is present in many industrialized products and the environment. Various analytical methods have been described using the Griess-Ilosvay reagent for the determination of nitrate in different matrices after its reduction to nitrite, in most cases with metallic cadmium as the reducer. This work proposes a new method using aluminu
Quím. Nova. Publicado em: 2021-02
-
4. Development of a Methodology Based on Extraction Induced by Emulsion Breaking for Copper Determination in Gasohol by Graphite Furnace Atomic Absorption Spectrometry
The development of a method based on extraction induced by emulsion breaking (EIEB) aiming copper determination in gasohol using graphite furnace atomic absorption spectrometry (GF AAS) is reported. Emulsification of the gasohol samples was carried out using nitric acid solution, (1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol surfactant (Triton X-114),
J. Braz. Chem. Soc.. Publicado em: 2021-02
-
5. Multivariate Analysis: Use of Doehlert Design (DD) for Optimization of a Simple Sample Preparation Procedure for the Determination of Inorganic Constituents in Cocoa Beans Employing Microwave Acid Digestion and ICP OES
This study presents a microwave-assisted procedure for sample preparation of cocoa beans using diluted HNO3 with H2O2 for the determination of Ba, Ca, Cu, K, Mg, Mn, P, S, Sr and Zn by inductively coupled plasma optical emission spectrometry (ICP OES). Doehlert modified design was used for optimization of experimental condition, and the volume of H2O2 (0, 0.
J. Braz. Chem. Soc.. Publicado em: 2020-10
-
6. The paths of Graves’ disease in the 21st century: precision medicine is closer
This study presents a microwave-assisted procedure for sample preparation of cocoa beans using diluted HNO3 with H2O2 for the determination of Ba, Ca, Cu, K, Mg, Mn, P, S, Sr and Zn by inductively coupled plasma optical emission spectrometry (ICP OES). Doehlert modified design was used for optimization of experimental condition, and the volume of H2O2 (0, 0.
Arch. Endocrinol. Metab.. Publicado em: 2020-10
-
7. Performance of Avocado Seed Activated Carbon as Adsorbent for Highly Sensitive Determination of Cd Using a Flow Injection System Online Coupled to TS-FF-AAS
A flow-injection preconcentration system using detection by the thermospray flame furnace atomic absorption spectrometry (FIA-TS-FF-AAS) is proposed. Cd2+ are adsorbed on avocado seed activated carbon (ASAC) packed into a cylindrical mini-column and eluted using HCl solutions for the detection system. A 25–1 fractional factorial and Doehlert matrix design
J. Braz. Chem. Soc.. Publicado em: 2020-01
-
8. PRÉ-CONCENTRAÇÃO BASEADA NA COPRECIPITAÇÃO USANDO CROMATO DE PRATA COMO CARREADOR PARA DETERMINAÇÃO DE COBRE POR FAAS
In the present paper, a preconcentration procedure based in the coprecipitation of copper by silver dichromate (Ag2CrO4) and consecutive determination by flame atomic absorption spectrometry (FAAS) was proposed. The experimental factors were optimized from application of the Doehlert matrix and the conditions set: chromate concentration 5.8 × 10-4 mol L-1,
Quím. Nova. Publicado em: 2019-01
-
9. Analytical Strategies for Determination and Environmental Impact Assessment of Inorganic Antimony Species in Natural Waters Using Hydride Generation Atomic Fluorescence Spectrometry (HG AFS)
This study proposes an optimized procedure for the determination of inorganic antimony species in natural waters using hydride generation atomic fluorescence spectrometry (HG AFS) and continuous flow system. The variables of the hydride generation system, such as pre-reduction time, hydrochloric acid concentration and sodium tetrahydroborate concentration, w
J. Braz. Chem. Soc.. Publicado em: 2018-01
-
10. Evaluation of volatile profiles obtained for minimally-processed pineapple fruit samples during storage by headspace-solid phase microextraction gas chromatography-mass spectrometry
Abstract This paper describes the application of the solid-phase microextraction (SPME) technique for the determination and monitoring of the volatile profile of minimally-processed pineapple fruit stored at various temperatures (-12 °C, 4 °C and 25 °C) for different periods (1, 4 and 10 days). The SPME fiber coating composed of Car/PDMS presented the bes
Food Sci. Technol. Publicado em: 09/03/2017
-
11. Method Development and Total Uncertainty Estimation for Boron, Sulfur and Phosphorus Determination in Mineral Fertilizer Using ICP OES
This study deals with B, S, and P determination in mineral fertilizer and S in commercial sulfur-formulation using inductively coupled plasma optical emission spectrometry. According to multivariate optimization using a Doehlert matrix, the analytes extraction in fertlizer can be conducted in open flask and heating on hot plate or in closed flask in microwav
J. Braz. Chem. Soc.. Publicado em: 2016-11
-
12. Multivariate optimization of a method for antimony determination by hydride generation atomic fluorescence spectrometry in hair samples of patients undergoing chemotherapy against Leishmaniasis
ABSTRACT A method was developed for determination of total antimony in hair samples from patients undergoing chemotherapy against Leishmaniasis based on the administration of pentavalent antimonial drugs. The method is based on microwave assisted digestion of the samples in a pressurized system, reduction of Sb5+ to Sb3+ with KI solution (10% w/v) in ascorbi
An. Acad. Bras. Ciênc.. Publicado em: 25/08/2016