Sulfur dioxide (SO2 PAUL)

MATERIAL AND REAGENTS

Measure of free and total SO2 with Sulfiduo unit (official method Frantz Paul / Rankine)

1 SO2 F. PAUL DISTILLER

1 TRIPOD FOOT SUPPORT DUR-AL 700x12 MM

1 DOUBLE WALNUT

1 UNIVERSAL CLAMP W/NUT

2 CLAMP JOINT 35 mm

3 SILICONE TUBE 7x11 mm

1 AIR MICROPUMP

1 BUTANE LIGHTER 11 MM

SODIUM HYDROXIDE 0.01 M

MIXED INDICATOR 4.4

HYDROGEN PEROXIDE 0.9% (3 Vol)

Ortho-PHOSPHORIC ACID 85%

OPERATIONAL TECHNIQUE

FREE SULFUR (Free SO2):

1- In the bubbler flask (pear shape), place 10 ml of 0.9% HYDROGEN PEROXIDE and a few drops of MIXED INDICATOR 4.4. Put the flask in place and hold it with the clamp.

2- In the spherical flask (250 mL) place 30 ml of the WINE to be analyzed and 10 ml of 85% ortho-PHOSPHORIC ACID. Put it in place without delay and put on the clamp.

3- Make air bubble for approximately 20 minutes, insufflating with a compressor or sucking with a vacuum pump.

4- Remove the bubbler flask and titrate it with 0.01 M SODIUM HYDROXIDE until olive green color. Record the volume spent of the burette and multiply it by 10.7. We thus obtain the free SO2 expressed in mg/L.

TOTAL SULFUR (Total SO2):

- Proceed in the same way as for FREE SULFUR but with applying heat in the wine sample using a bunsen burner or heating blanket.

OBSERVATIONS

See Paul Distiller

See Sulfiduo