A sensitive flow-based procedure for spectrophotometric speciation analysis of inorganic bromine in waters

Autor(es)

Rocha, Diogo L. ^[1] ; Machado, Marcos C. ^[1] ; Melchert, Wanessa R. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP - Brazil

^[2] Univ Sao Paulo, Escola Super Agr Luiz de Queiroz, BR-13418970 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Talanta; v. 129, p. 93-99, NOV 1 2014.
• Citações Web of Science: 5

Resumo

A flow-based system with solenoid micro-pumps and long path-length spectrophotometry for bromate and bromide determination in drinking water is proposed. The method is based on the formation of an unstable dye from the reaction between bromate, 2-(5-dibromo-2-pyridylazo)-5-(diethylamino)phenol (5-Br-PADAP) and thiocyanate ions. A multivariate optimization was carried out. A linear response was observed between 5.0 and 100 mu g L-1 BrO3- and the detection limit was estimated as 2.0 mu g L-1 (99.7% confidence level). The coefficient of variation (n=20) and sampling rate were estimated as 1.0% and 40 determinations per hour, respectively. Reagent consumption was estimated as 0.17 mu g of 5-Br-PADAP and 230 mu g of NaSCN per measurement, generating 6.0 mL of waste. Bromide determination was carried out after UV-assisted conversion with K2S2O8 using 300 mu L of sample within the range 20-400 mu g L-1 Br-. The generated bromate was then determined by the proposed flow system. The results for tap and commercial mineral water samples agreed with those obtained with the reference procedure at the 95% confidence level. The proposed procedure is therefore a sensitive, environmentally friendly and reliable alternative for inorganic bromine speciation. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 11/14071-1 - Monitoramento de toxinas na torta de co-produtos de biodiesel e análises de especiação em amostras de interesse ambiental e agronômico
• Beneficiário: Wanessa Melchert Mattos
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/23498-9 - Sistemas avançados de análises químicas em fluxo: aplicações nas áreas tecnológica, agronômica e ambiental
• Beneficiário: Elias Ayres Guidetti Zagatto
• Modalidade de apoio: Auxílio à Pesquisa - Temático