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

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.

Ozonation of ethinylestradiol in aqueous-methanolic solution: direct monitoring by electrospray ionization mass spectrometry

“…[27][28][29] Electrospray ionization mass spectrometry (ESI-MS), because of its appealing and unique attributes, has rapidly becoming an alternative approach suitably employed to a direct monitoring of a increasing number of relevant environmental processes. [30][31][32][33][34][35][36][37][38][39][40] In these inquiries, the information provided by the MS (the m/z values of the ionic species) and MS/MS data (the fragmentation profiles of a given mass-selected ion) are meticulously evaluated aiming to propose chemical structures of products (and in some cases transient intermediates) likely formed in the condensed phase. 41 The identification of by-products arising from oxidative treatments, which can be more risky than the own precursors indeed, 42 is an important point that must be taken into consideration for the evaluation of the overall performance of a given process.…”

The abatement of indigo carmine using active chlorine electrogenerated on ternary Sb2O5-doped Ti/RuO2-ZrO2 anodes in a filter-press FM01-LC reactor

“…Guaraldo et al, 2013, andDe Urzedo et al, 2007, studied the degradation of IC using a photoelectrocatalytic treatment with Ti/TiO 2 /WO 3 , and hypochlorite in aqueous medium, respectively. The formation of isatin-5-sulfonic acid as the main by-product resulting from the degradation was a common denominator in both investigations [36,37]. In order to confirm the identity of this by-product, an UVvis analysis was carried out with a standard of isatin-5-sulfonic acid (supplementary data 3).…”

ESTUDO DA ATIVIDADE CATALÍTICA DO PÓ DE OSSO BOVINO IMPREGNADO COM Fe(III): NOVO MATERIAL PARA FOTODEGRADAÇÃO DO CORANTE ÍNDIGO CARMIM

“…Um grande número de artigos descrevem a aplicação dos POAs para degradar corantes em solução aquosa. Por exemplo, uma matriz composta por TiO 2 imobilizada nas superfícies internas de tubos de quartzo expostos continuamente a uma fonte de UV tem sido utilizada com sucesso para degradar vários corantes (Urzedo et al, 2007). Experiências em pequena escala mostraram que o sistema TiO 2 /luz solar possui alta eficiência na remoção da cor a partir de soluções aquosas de indigo carmim (Liao et al, 2009).…”