Sequential injection system for the spectrophotometric determination of reducing sugars in wines

• Type: Article in International Scientific Journal
• Date: 2000

Authors

Araujo, AN (Author) FFUP; Lima, JLFC (Author) FFUP; Rangel, AOSS (Author) Other; Segundo, MA (Author) Other

Journal

Title: Talanta

Vol. 52

Pages: 59-66

ISSN: 0039-9140

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 28 Citations

Scopus - 30 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-01N

DOI: 10.1016/s0039-9140(99)00338-0

Abstract (EN): 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) <2.1%). The results obtained from 19 wine samples were comparable to those obtained by the reference method.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8