Evaluation of the correlation between the results obtained with CDR WineLab® and the official methods

Professor Massimo Innocenti, manager of the Applied Electrochemistry Laboratory, Department of Chemistry “Ugo Schiff” of the University of Florence, has conducted a study with the purpose of evaluating the accuracy and precision of the CDR WineLab^® analysis system for wine.

22 samples of commercial wine from various origins have been chosen and anilysed through CDR WineLab^®  system, by testing the main parameters to be carefully monitored throughout the wine-making process.

In particular the correlation between the results obtained with CDR WineLab® and the OIV official methods (International Organisation of Vine and Wine) on the following parameters has been evaluated:

• Acetic acid – reference method OIV-MA-AS313-04 (HPLC)
• Total acidity – reference method OIV-MA-AS313-01 R2015 par 5.2 (potentiometric titration)
• L-Malic acid – reference method OIV-MA-AS313-16 (HPLC)
• L-Lactic acid – reference method OIV-MA-AS313-16 (HPLC)
• Alcohol – reference method OIV MA-AS312-01A R2016 4.B
• Total SO₂ – reference method OIV-MA-AS323-04B. Ripper–Schmitt method
• Free SO₂ – reference method Ripper–Schmitt but without performing the alkalinisation (OIV-MA-AS323-04B)
• Sugars – reference method OIV-MA- AS311-03 (HPLC)
• IPT (Total Polyphenols Index) UV at 280 nm – reference method OIV-OENO 419D-2015

The Pearson correlation coefficient was used to verify the presence of a correlation between the data (R²).

Furthermore the repeatibility and reproducibility of each test were evaluated by performing 5 consecutive analyses for 5 days of the standard solutions.

All analyses tested with the CDR WineLab ^® instrumentation provided results that were statistically correlated with those obtained with the official methods.

The detection limits and the reproducibility of the analyses were comparable or better than those obtained with the official methods.

 The method of analysis in the case of CDR WineLab^® instrumentation is very simple: for each of the analyses carried out, the only sample preparation required is degassing (if necessary). Alternatively, the sample is used as it is except for the analysis of the alcohol content where a dilution is required to be carried out with the dedicated kit supplied. Regarding the actual analysis, the instrument is very simple to use, does not require calibration and is ready to be used to perform the measurement. The operator is assisted by detailed instructions visible on the touch screen of the instrument, present for each method of analysis. This means easy execution of the analysis even by non-expert personnel.

All the material needed to perform the analysis is supplied in specific kits by the manufacturer.

With the CDR WineLab^® analysis system there is also a considerably reduced consumption of both sample and reagents compared to some of the corresponding official methods, for example in the analysis of free and total sulphur dioxide.