DETECTION OF HYDROGEN SULPHIDE (H2S) IN WINE
The Test Paper allows the EASY and RELIABLE detection of hydrogen sulphide (H2S)
COLOUR REACTION
The white test paper changes, in the presence of sulphide ions and hydrogen sulphide, to a brown – black colour, depending on the concentration.
INSTRUCTIONS FOR USE
For the determination of Hydrogen Sulphide (H2S), first wet the test paper with distilled water and hold it up in the air to be tested. Place a drop of the sample on the test paper. A brown colouration, on that part of the paper where water was applied, shows the presence of hydrogen sulphide.
LIMIT OF SENSITIVITY
The presence of 5mg/L of Hydrogen Sulphide produces an easily recognisable brown ring.
TREATMENT OF THE WINE
Hydrogen Sulphide (H2S) gas occurs in both red and white wine. It produces a foul smell, reminiscent of rotten eggs. If not treated immediately with a Standard Copper Sulphate solution (available from ANPROS P/L), then the (H2S) gas which when formed in wine can change into other very smelly substances such as mercaptans and organic sulphides which are more difficult to remove from the wine.
Initial addition equals Litres of Wine divided by 18 = mls of copper sulphate solution = 0.25mg/L (ppm)
For Example Treating 1000L of wine
1000 divided by 18 = 55.6ml = 1mg/L of copper
55.6 divided by 4 = 13.9ml (0.25 mg/L = 0.25 mg/L of copper)
If the odour or taste of hydrogen sulphide is not removed after the initial addition of copper sulphate solution (ie 13.9ml), then another amount of copper sulphate solution (13.9ml = 0.25mg/L of copper) is added and the wine tested for the presence of hydrogen sulphide.
If the (H2S) still remains then successive amounts of 13.9ml of copper sulphate solution can be added to the wine. Usually, a total of only 0.25 – 0.75mg/L of copper are required. A maximum addition of 1.0 – 1.25mg/L of copper may be added to the wine.