Issue |
Analusis
Volume 28, Number 1, January/February 2000
IR-Raman
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Page(s) | 77 - 82 | |
Section | Original articles | |
DOI | https://doi.org/10.1051/analusis:2000100 |
DOI: 10.1051/analusis:2000100
Spectrophotometric determination of carbon dioxide and sulphur dioxide in wines by flow injection
G.T. Atanassov, R.C. Lima, R.B.R. Mesquita, A.O.S.S. Rangel and I.V. TóthEscola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Dr. António Bernardino de Almeida, 4200-072 Porto, Portugal
(Received April 21, 1999; revised January 17, 2000; accepted February 9, 2000.)
Abstract
Flow injection analysis (FIA) methods for the spectrophotometric determination of CO2 and SO2 in
wines are described. The determination of CO2 is based on the colour change of a low capacity buffer
(containing an acid-base indicator) due to the dissolved carbon dioxide. The determination of SO2 is
based on the decoloration of malachite green by sulphur dioxide. Two FIA manifolds are presented; one for
the determination of CO2 in sparkling wines and another for the simultaneous determination of CO2
and SO2 in table wines. The analytes are isolated inside the manifold from the sample matrix using
gas-diffusion units. Regression equations (FIA versus reference methods) showed no statistical difference,
at 95 % confidence level, between the two sets of results for both determinations; additionally, for the
determination of CO2, recovery values between 93.5 % and 111 % were found. RSD lower than 4.5 % for
SO2 and 2.4 % for the CO2 determination were found. The sampling rates achieved were: 30 h-1
for the uniparametric system and 40 h-1 for the biparametric system. The single determination
manifold is applicable in the concentration ranges of 0.5 to 4 g L-1 of CO2, and the simultaneous
determination manifold in the range of 0.25 to 3 g L-1 of CO2 and 0.05 to 0.3 g L-1 of
SO2.
Key words: Carbon dioxide -- sulphur dioxide -- wines -- flow injection -- spectrophotometry.
© EDP Sciences, Wiley-VCH 2000