Using 34SO2 to Detect H2S Formation in Canned Wine

53 pagesCanned white wines have a reputation for producing hydrogen sulfide during storage in the can, producing a foul, rotten-egg smell upon opening. Over the past decade, the source of this H2S has been anecdotally attributed to sulfur dioxide despite no support from published literature. Sulfur dioxide, which is commonly added to wines as a preservative and to prevent oxidative reactions, is thought to produce H2S through the following reaction:2Al0 (s) + SO2 (aq) + 6H+ (aq) → 2Al3+ (aq) + H2S (g) +2H2O(l) This pathway to producing H2S can be verified spiking 34S labeled SO2 into white wine and using gas chromatography – mass spectrometry to detect changes in H234S intensity. This body of work provides some of the preparatory work required to confirm SO2 as a source of H2S in canned white wine. This work details the synthesis and quantification of unlabeled and labeled SO2 in solution. Both forms of SO2 were then aliquoted and spiked into white wine for headspace GC-MS analysis to validate their successful synthesis. The variability in the native ratio of 34SO2 to 32SO2 was determined by analyzing the concentration of SO2 in the headspace of the control wine only. An equilibration experiment was performed to determine the length of time required for a labeled SO2 spike to equilibrate with native SO2 from the original wine