Valfredo Azevedo Lemos

All papers authored by Valfredo Azevedo Lemos

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2021 Vanessa Jesus Ferreira, Marina Santos de Jesus, Mayara Costa dos Santos, Wesley N. Guedes

, Valfredo A. Lemos

, Cleber G. Novaes

, Floriatan Santos Costa

, Clissiane S. Viana Pacheco, Erik Galvão Paranhos da Silva

, Fábio Alan Carqueija Amorim

Multivariate optimization of ultrasound-assisted liquid–liquid microextraction based on two solvents for cadmium preconcentration prior to determination by flame atomic absorption spectrometry

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This paper is made freely available by the publisher.

Adilson Santos

, Tereza Santos

, Valfredo Lemos

, Alexilda de Souza

Yellow Mombin (Spondias mombin L.) Seeds from Agro-Industrial Waste as a Novel Adsorbent for Removal of Hexavalent Chromium from Aqueous Solutions

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2020 Leane Santos Nunes

, Maria Graças Andrade Korn, Valfredo Azevedo Lemos

A novel direct-immersion single-drop microextraction combined with digital colorimetry applied to the determination of vanadium in water

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Rebeca Moraes Menezes, Walter Nei Lopes Santos, Uneliton Neves Silva, Valfredo Azevedo Lemos

A Miniaturized Gas-Liquid Separator for Use in Liquid-Phase Microextraction Procedures: Determination of Mercury in Food

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Luana Bastos Santos, Jeferson Alves Barreto, Rosivan dos Santos de Assis, Cheilane Tavares de Souza, Sérgio Luís Costa Ferreira, Cleber Galvão Novaes, Valfredo Azevedo Lemos

Solid-Phase Extraction and Detection by Digital Image Directly in the Sorbent: Determination of Nickel in Environmental Samples

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Vanessa de Jesus Ferreira, Vanessa de Jesus Ferreira, Jorge S. Almeida

, Valfredo A. Lemos

, Olivia M. C. de Oliveira, Karina S. Garcia, Leonardo S. G. Teixeira

Determination of Cu, Ni, Mn, and Pb in diesel oil samples using reversed-phase vortex-assisted liquid-liquid microextraction associated with energy dispersive X-ray fluorescence spectrometry

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Valfredo Azevedo Lemos

, Ivanilson Vieira Souza Junior, Luana Bastos Santos, Jeferson Alves Barreto, Sérgio Luís Costa Ferreira

A New Simple and Fast Method for Determination of Cobalt in Vitamin B12 and Water Samples Using Dispersive Liquid-Liquid Microextraction and Digital Image Analysis

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Marcos Almeida Bezerra, Ricardo Erthal Santelli, Valfredo Azevedo Lemos

, Juscelia Pereira dos Santos, Bernardo Ferreira Braz, Luana Bastos Santos

Strategies to Make Methods Based on Flow Injection Analysis Greener

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Leane Santos Nunes, Maria das Graças Andrade Korn, Valfredo Azevedo Lemos

Direct Immersion Single-Drop Microextraction and Continuous-Flow Microextraction for the Determination of Manganese in Tonic Drinks and Seafood Samples

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Marcos Almeida Bezerra, Valfredo Azevedo Lemos

, Cleber Galvão Novaes, Jeferson Alves Barreto, Juscelia Pereira Santos Alves, Djalma Menezes de Oliveira

, Uillian Mozart Ferreira da Mata Cerqueira, Queila Oliveira dos Santos, Sulene Alves Araújo

Automation of continuous flow analysis systems – a review

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Sergio L. C. Ferreira, Joao B. Pereira Junior, Lucas C. Almeida, Luana B. Santos, Valfredo A. Lemos

, Cleber G. Novaes, Olivia M. C. de Oliveira, Antonio F. S. Queiroz

Strategies for inorganic speciation analysis employing spectrometric techniques–Review

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Jeferson Barreto, Valfredo Lemos

, Djalma de Oliveira, Uillian Mozart Cerqueira, Lucília Meira, Marcos Bezerra

Use of Arduino in the Development of a New and Fast Automated Online Preconcentration System Based on Double-Knotted Reactor for the Mn Determination in Tea Samples by Flame Atomic Absorption Spectrometry (F AAS)

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Marcos Almeida Bezerra, Valfredo Azevedo Lemos

, Cleber Galvão Novaes, Raildo Mota de Jesus, Hélio Rocha Souza Filho, Sulene Alves Araújo, Juscelia Pereira Santos Alves

Application of mixture design in analytical chemistry

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Fabio de S. Dias

, Salvador C. de S. R. Neto, Laís de N. Pires, Valfredo A. Lemos

Emulsification solidified floating organic drop microextraction assisted by ultrasound for the determination of nickel, cobalt and copper in oyster and fish samples

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2019 Analú P. Santos, Márcio Js Santos, Maria Graças Andrade Korn, Valfredo A. Lemos

Determination of cadmium in bread and biscuit samples using ultrasound‐assisted temperature‐controlled ionic liquid microextraction

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This paper was not found in any repository; the policy of its publisher is unknown or unclear.

Luana Bastos Santos, Djalma Menezes de Oliveira

, Alexilda Oliveira de Souza, Valfredo Azevedo Lemos

A new method for the speciation of arsenic species in water, seafood and cigarette samples using an eggshell membrane

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Jeferson Alves Barreto, Rosivan dos Santos de Assis, Ricardo Jorgensen Cassella

, Valfredo Azevedo Lemos

A novel strategy based on in-syringe dispersive liquid-liquid microextraction for the determination of nickel in chocolate samples

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Valfredo Azevedo Lemos

, Rafael Vasconcelos Oliveira, Walter Nei Lopes dos Santos, Rebeca Moraes Menezes, Luana Bastos Santos, Sérgio Luís Costa Ferreira

Liquid phase microextraction associated with flow injection systems for the spectrometric determination of trace elements

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Raineldes A. Cruz Junior, Adriano V. B. Chagas, Caio S. A. Felix, Rosemario C. Souza, Luciana A. Silva, Valfredo A. Lemos

, Sergio L. C. Ferreira

A closed inline system for sample digestion using 70% hydrogen peroxide and UV radiation. Determination of lead in wine employing ETAAS

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2018 Queila O. dos Santos, Mario M. Silva Junior, Valfredo A. Lemos

, Sergio L. C. Ferreira, Jailson B. de Andrade

An online preconcentration system for speciation analysis of arsenic in seawater by hydride generation flame atomic absorption spectrometry

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All papers authored by Valfredo Azevedo Lemos