The reference in enology
since 1855

PRINCIPLE

The free sulphurous anhydride is titrated directly in the sample with a titrated iodine solution in the presence of a starch indicator. Subsequently and on a second sample, the SO2 is set free of the combinations it forms with an alkaline solution. Then, the same titration as above is done again and the total SO2 is obtained. The difference between the 2 results gives the combined SO2.

EQUIPMENT AND REAGENTS

• Stand, rod, and clamp for burette
• 1 Automatic self-zeroing burette (25 ml) (Ref. 600148)
• 1 Rubber bulb for automatic burette (Ref. 606000)
• 1 Siphon for ground-joint flask (Ref. 600194)
• Green clip for ground-joint assembly (Ref. 600195)
• 1 VERSILIC hose (diameter 5/7) (Ref. 617602)
• 1 Amber glass ground-joint flask (500ml) (Ref. 600193)
• 1 Grey-blue stopper N°10 (Ref. 650110P)
• 1 Erlenmeyer graduated ground-joint flask (250 ml) (Ref. 615250E)
• 1 2-mark volumetric pipette (50 ml) (Ref. 603010)
• 1 2-mark volumetric pipette (25 ml) (Ref. 603025)
• 1 2-mark volumetric pipette (10 ml) (Ref. 603050)
• 1 Dropping-pipette with rubber bulb (Ref. 630000)
   
• 500 ml of iodine solution N/50 (Ref. 936500)
• 500 ml of sodium hydroxide 1 – 125N (Ref. 934500)
• 500 ml of diluted sulphurous acid 1/10 (932500)
• 125 ml of indicator solution (Ref. 937125)

WARNING