A fast and environment-friendly method for determination of chemical oxygen demand by using the heterogeneous Fenton-like process (H2O2/Fe(3-x)Co(x)O4 nanoparticles) as an oxidant.

Autor: Esteves LC; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Oliveira TR; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Souza EC Jr; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Bomfeti CA; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Gonçalves AM; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Oliveira LC; Departamento de Química, ICEx, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, Minas Gerais, Brazil., Barbosa F Jr; Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040903 SP, Brazil., Pereira MC; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil., Rodrigues JL; Instituto de Ciência, Engenharia e Tecnologia, Universidade Federal dos Vales Jequitinhonha e Mucuri, Teófilo Otoni 39803-371, Minas Gerais, Brazil. Electronic address: jairo.rodrigues@ufvjm.edu.br.
Jazyk: angličtina
Zdroj: Talanta [Talanta] 2015 Apr; Vol. 135, pp. 75-80. Date of Electronic Publication: 2014 Dec 11.
DOI: 10.1016/j.talanta.2014.11.055
Abstrakt: An easy, fast and environment-friendly method for COD determination in water is proposed. The procedure is based on the oxidation of organic matter by the H2O2/Fe(3-x)Co(x)O4 system. The Fe(3-x)Co(x)O4 nanoparticles activate the H2O2 molecule to produce hydroxyl radicals, which are highly reactive for oxidizing organic matter in an aqueous medium. After the oxidation step, the organic matter amounts can be quantified by comparing the quantity of H2O2 consumed. Moreover, the proposed COD method has several distinct advantages, since it does not use toxic reagents and the oxidation reaction of organic matter is conducted at room temperature and atmospheric pressure. Method detection limit is 2.0 mg L(-1) with intra- and inter-day precision lower than 1% (n=5). The calibration graph is linear in the range of 2.0-50 mg L(-1) with a sample throughput of 25 samples h(-1). Data are validated based on the analysis of six contaminated river water samples by the proposed method and by using a comparative method validated and marketed by Merck, with good agreement between the results (t test, 95%).
(Copyright © 2014 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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