Analysis of sulfur dioxide in wine, as performed on the HI84500 mini titrator, utilizes a simple sample preparation, a high quality titrant dosing pump, potentiometric endpoint detector, and automatic computations. To maintain the high precision of the titrator, a simple pump calibration procedure is performed with HI84500-55 pump calibration solution. The pump calibration procedure involves the analysis of a known volume of a known solution. The pump calibration procedure should be performed anytime the titrant, syringe, tubing or ORP electrode is replaced. Periodic calibrations should be performed in order to accurately determine the free and total sulfur dioxide levels in wine.
The HI84500 determines the free and total sulfur dioxide concentration in wine using the Ripper method. Excess iodide is added to the wine sample and reacts with the iodate titrant to produce iodine:
IO3- + 5I- + 6H+ → 3I2 + 3H2O
The iodine produced reacts with sulfur dioxide in the wine according to the redox reaction below:
H2SO3 + I2 → H2SO4 + 2HI