Determination of Total Sulfur Dioxide in wine

With CDR WineLab^® is possible to determine the Total Sulfur Dioxide in wine in 1 minute with a simple photometric reading using the wine as is without having to resort to the distillation according with the reference method OIV or to the iodometric titration according with the simplified method. Calibration is not necessary.

The Analyzers CDR WineLab^® for determining Total sulfur dioxide in Wine and Must

The system is supplied pre-calibrated and ready for use.
Results are expressed in accordance with the reference method.
It is also possible to standardize the system using samples with a known titration.
The reagents have a shelf-life untill 18 months
The analytical methods are simple: the system does not require an equipped laboratory or skilled staff.

	CDR WINELAB®	CDR WINELAB® JUNIOR
Analyses	Wine and Must: Alcohol by Volume Acetic acid (volatile acidity) Fermentable Sugars Total Acidity L-Lactic Acid L-Malic Acid Free sulfur dioxide Total sulfur dioxide Yeast Assimilable Nitrogen (YAN) Gluconic Acid Acetaldehyde (Ethanal) pH Total Polyphenols Index Glycerol Colour (tonality and intensity) Total Polyphenols (Folin Ciocalteu) Total Anthocyanins Polymerised Anthocyanins HCl Index Tannins Catechins Copper	Configuration with tailored panel of analyses
Simultaneous Sample Analyses	16	3
Multiple Analyses on a Sample		–

Method

Test type: End Point.
Time testing: one test 1 minute – 80 Test/Hour.
Are possible test sessions with several samples, up to a maximum of 16.

Calibration curve

The calibration curve of CDR WineLab^®, obtained using reference methods.

Test Principle

SO₃^2- + RSSR <—–> RSSO₃– + RS-.
The sulfur dioxide contained in a wine is made to react with an organic disulphide in order to form a colored compound, whose intensity, measured at 420 nm in end-point, is directly proportional to the concentration of total sulfur dioxide in the sample.

Definition and scope of the test

Sulfur dioxide (SO2) is used in oenology mainly as preservative, but also for other purposes (for example for antiseptic, antioxidant, antioxidasic, solubilizing, combining and clarifying functions). Part of the SO2 that is added as potassium metabisulfite to musts and wines undergoes a series of reactions. Therefore, after a short period of time, most of the sulfur dioxide reacts with some of the substances present, binds with them and forms addition compounds (combined sulfur dioxide) that are unable to express the typical properties of unbound molecules. Therefore, only the part that does not combine (free sulfur dioxide) plays an important role in preserving wine from oxidizing alterations and from some micro-organisms. This test can be used to determine the total content of SO2 in wine, which is the sum of the free and combined sulfur dioxide fractions.

Reagent test Kits

The reagents are packaged in foil pouches containing 10 tubes useful to perform 10 analyses.

This is the minimum package that allows the use of CDR systems even to those who need to make a few analyses, thus not wasting reagents.

There are also boxes of 100 tests, however, packaged in 10 bags of 10 tubes containing the reagent.

Code. *300350: 10 tests 

Code. *300334: 100 tests (10 packages of 10 tests)

The reagents have a shelf-life of 18 months.

Processing – Sample Volume – Measuring Range

Wine: use as is.

Test	Measuring range (mg/L SO2)	Resolution	Repeatability
Total SO2 White Wine	15 – 250	1	2,5 mg/L

For samples with SO₂ > 200 mg/L, use 10 µL of sample and multiply the result by 2.5.

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