Wine Quality Analysis
By: Nicole Amann, Analytix Volume 2007 Article 5
Product Manager Analytical Standards email@example.com
When applied to the compositional analysis of wine, including naturally occurring compounds, additives and contaminants, analytical chemistry plays an important role in ensuring both the quality of the wine and consumer safety. The notorious 1985 glycol-doping scandal of Austrian and German wines is a prime example.
However, wine presents a complex matrix: Flavors, sugars, carboxylic acids, tannins, phenols, amino acids, alcohols, esters and acetates are among the many typical wine constituents, and many more are present as unwanted contaminants that must be monitored. The composition and ratio of constituents combine to give each wine its unique flavor and texture, a ratio that is easily disturbed by environmental conditions, shipping and storage. Analysts involved in the quality control or regulation of wine require reliable analytical methods and standards for its determination. To help analysts produce definitive, quantitative results, Sigma- Aldrich offers three Fluka-brand standards for wine analysis. Together, these standards include many of the most commonly analyzed sugars, acids and alcohols in wine.
Ion chromatography (IC) is useful because it permits the simultaneous analysis of many important wine components. The IC chromatograms of the Fluka standards, along with samples of sweet and dry wines, appear in the accompanying fi gures. These samples were provided by a Swiss vintner that performs in-house QA to show the quality of their wine as a means to help ensure customer confidence in their product. Notable are the elevated sugars in the sweet wine and elevated acids in the dry wine.
This article was developed in close cooperation with Sertec-Electronics in Olten (Switzerland). We want to thank especially R. Schwarz for providing the measurements and giving us the opportunity to publish these.
Table 1.Comparison of dry and sweet wine composition measured using ion chromatography with RI detection
|Cat. No.||Brand||Description||Pack Size||Components, 100 mL solution contain:|
|19433||Fluka||Wine Analysis: stock solution I||100 mL||0.5 g Citric Acid, 0.5 Malic Acid, 0.5 g Succinic Acid, 0.5g Acetic Acid 2.0 g Tartaric Acid, 2.0 g Lactic Acid|
|19065||Fluka||Wine Analysis: stock solution II||100 mL||0.5 g 2,3-Butanediol, 2.0 g Glucose, 2.0 g Fructose, 5.0 g Glycerol|
|12159||Fluka||Wine Analysis: stock solution IV||100 mL||10.2 g (10 mL) Ethanol|
Figure 1.Fluka wine standard solutions (see Table 1 for peak IDs)
Figure 2.Dry wine sample
Figure 3.Sweet wine sample
Columns: Sertec-Wine-ST3 300 x 7.8 mm with Sertec-Wine-ST1, 50 x 4.6 mm precolumn Mobile phase: 2.5 mM sulfuric acid
Flow rate: 0.65 mL/min.
Temperature: 50 °C
Injection: 20 μL, wine sample diluted 1:9 with 10 mM sulfuric acid and filtered