Determination of sulfur dioxide in wines by gas-diffusion flow injection analysis utilizing modified electrodes with electrostatically assembled films of tetraruthenated porphyrin Original Research Article

Reported is a new method for the determination of both free and total SO2 in wine, specially designed for FIA. The method involves separation of the analyte using a flow through gas diffusion unit, in line with an amperometric detector consisting of a glassy carbon electrode modified with electrostatically assembled films of a tetraruthenated porphyrin. The results demonstrate a good accuracy, comparable with those obtained using the conventional iodometric method. In addition, the method can be readily applied to red, white and rose wines; it is free from interference of the other compounds of wine, consumes small amounts of sample and is faster than the iodometric method.