Validation of a fast automated photometric method for the analysis of sulfur dioxide in wines

In this work a simple and rapid automated analytical method for the determination of sulfur dioxide in wines by employing a sequential automatic analyser was validated. The methodology is based on the reaction of sulfur dioxide with 5,5′-dithiobis-(2-nitrobenzoic acid) in an alkaline medium followed by photometric detection. The linearity of the calibration curve was excellent ( R 2 = 1.000) and the LOQ (2.00 mg L −1 ) was well suited for the monitoring of regulatory limits. The accuracy and precision were evaluated with reference materials, providing highly successful results (RSD%