| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 99.39 KB | Adobe PDF |
Advisor(s)
Abstract(s)
A sequential injection system for the spectrophotometric determination of reducing sugars in wines is described.
The methodology is based on the formation of a coloured complex produced by the reaction of copper (I) with
2,9-dimethyl-1,10-phenanthroline (neocuproine), after reduction of copper (II) to copper (I) by reducing sugars. In the
present SI system, a dialysis unit was incorporated not only to allow the sample dilution, but also to minimise the
interference of some coloured compounds. In this way, direct sample introduction into the system was possible,
without any previous treatment of the wine samples. The proposed method can be applied to the determination of
reducing sugars in two concentration ranges: from 2 to 25 g l 1 (table wines) and from 20 to 140 g l 1 (Port wines).
To perform determinations in these two ranges, the manifold configuration remained the same; just a few operational
parameters were changed in the controlling software. A sampling-rate of 14–18 samples per hour was obtained with
good repeatability for ten consecutive injections of wine samples (relative standard deviations (RSD) B2.1%). The
results obtained from 19 wine samples were comparable to those obtained by the reference method.
Description
Keywords
Sequential injection Reducing sugars Wine Dialysis unit Spectrophotometry
Pedagogical Context
Citation
ARAÚJO, Alberto N.; LIMA, José L. F. C.; RANGEL, António O. S. S. - Sequential injection system for the spectrophotometric determination of reducing sugars in wines. Talanta. ISSN 0039-9140. Vol. 52 (2000), p. 59–66
Publisher
Elsevier