Artigo Produção Nacional Revisado por pares

Indigo Carmine degradation by hypochlorite in aqueous medium monitored by electrospray ionization mass spectrometry

2007; Wiley; Volume: 21; Issue: 12 Linguagem: Inglês

10.1002/rcm.3037

ISSN

1097-0231

Autores

Ana Paula Fonseca Maia de Urzedo, Clésia C. Nascentes, Maria E. R. Diniz, Rodrigo Ramos Catharino, Marcos N. Eberlin, Rodinei Augusti,

Tópico(s)

Electrochemical sensors and biosensors

Resumo

Abstract The degradation of the dye Indigo Carmine by hypochlorite in aqueous solution was monitored by electrospray ionization mass spectrometry in the negative ion mode (ESI(—)‐MS). Hypochlorite was highly efficient in removing the color of aqueous solutions of the dye. ESI(—)‐MS monitoring showed that concomitant with the Indigo Carmine consumption two transient species appeared (detected as doubly charged anions) probably formed via a net insertion of two hydroxyl groups at the exocyclic CC bond followed by the incorporation of two (mainly) or one oxygen atoms at the indolic rings of the dye. Structures of these products were proposed based on the ESI(—)‐MS/MS data and high accuracy mass measurements. These two transient intermediates quickly decomposed, both in the condensed and in the gas phase, to yield mono‐charged anions. Based on these results, a route for the Indigo Carmine degradation by hypochlorite in aqueous solution has been proposed. Copyright © 2007 John Wiley & Sons, Ltd.

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