Um método verde e sensível para determinação de fenóis em amostras de água utilizando sistemas aquosos bifásicos

• Ano de defesa: 2009
• Autor(a) principal: Rodrigues, Guilherme Dias
• Orientador(a): Silva, Maria do Carmo Hespanhol da
• Banca de defesa: Queiroz, Maria Eliana Lopes Ribeiro de , Neves, Antônio Augusto , Oliveira, Marcone Augusto Leal de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Agroquímica
• Departamento: Agroquímica analítica; Agroquímica inorgânica e Físico-química; Agroquímica orgânica
• País: BR
• Palavras-chave em Português: Sistema aquoso bifásico; Química verde; Determinação de fenóis; Efluentes industriais; Pré-concentração; Águas residuais
• Palavras-chave em Inglês: Aqueous two phase systems; Green chemistry; Phenols determination; Industrial effluents; Pre-concentration; Wastewater
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://locus.ufv.br/handle/123456789/2082

This work initially presents a brief review of aqueous two- phase systems (ATPS), including the history, principles and properties of the technique. Furthermore, a divulgation on green methods for determination of phenols in water is shown, since these substances have high toxicity. The disposal of phenolic compounds is regulated in several countries, including Brazil, through the resolution CONAMA nº 357 (March 17, 2005) and, associated with this, there is a constant search for environmental safe methods which are according to the principles of Green Chemistry, such as: liquid phase microextraction, solid phase microextraction, flow analysis, cloud point extraction and aqueous two-phase. In this work a greener and sensitive procedure for the determination of phenol and o cresol in water samples, exploiting ATPS (PEG1500 + salt + water) was developed. The method is based on the reaction among phenol, sodium nitroprusside and hydroxylamine hydrochloride in alkaline medium, producing the complex anion [Fe2(CN)10]10 which concentrates in the top phase of the system. The method shows the following analytical features: linear range of 1.00 to 500 μg kg 1, coefficient of variation equal 0.38 and 0.30 %, limit of detection of 1.27 and 1.88 μg kg 1, and limit of quantification of 4.22 and 6.28 μg kg 1, for phenol and o cresol, respectively. Recoveries within 95.7 to 107 % were obtained for water samples. Besides, excellent agreement between the proposed method and the standard method was observed.