Around voltammetry: from colouring matters to beer

A.A. Barros*

REQUIMTE, Departamento de Química da Faculdade de Ciências da Universidade do Porto,

Rua do Campo Alegre, 687, 4169-007 PORTO, Portugal

 

Abstract

This paper is based on the plenary lecture that I was invited to present in the VIII Encontro Ibérico de Electroquímica and XIII Encontro da Sociedade Portuguesa de Electroquímica, a meeting which was “a tribute to the late Prof. João Cabral”.The best way I found to honour his memory was to present the highlights of an investigation of 25 years in voltammetry, which would never happen without the enthusiasm and the guidance of Prof. João Cabral.

After a first publication, in 1986, on the adsorptive stripping voltammetry of synthetic colouring matters, our investigation was soon directed towards the new analytical possibilities opened by the appearance of new voltammetric instrumentation capable of very fast potential scans. The instrumental elimination of oxygen interference obtained in the fast adsorptive stripping of some species reversibly reducible on the hanging mercury drop electrode (HMDE) was a first achievement, immediately followed by the development of a HMDE flow detector for the determination of those species. This detector is being applied in the flow determination of several compounds, with the determination of diacetyl deserving a special reference. In fact the determination of this compound it is very important for the brewing industry and it was possible to develop an equipment capable of its determination in flow: diacetyl is extracted from beer by pervaporation, then derivatized with orto-phenytlenediamine and finally determined by HMDE adsorptive stripping voltammetry.

Keywords: Prof. João Cabral, adsorptive stripping voltammetry, HMDE, oxygen elimination, flow detection, diacetyl, beer.

 

 

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References

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*Corresponding author. E-mail address: ajbarros@fc.up.pt