We completed development of an analytical procedure using headspace gas chromatography (HS-GC) coupled with sulfur chemiluminescence detection (SCD) which can rapidly and precisely quantify molecular and free sulfur dioxide in wine. The method requires minimal sample preparation and involves no chemical reagents (with the exception of a trace internal standard). At room temperature the method can successfully detect levels of molecular sulfur dioxide at concentrations as low as 0.03 mg/L. The total chromatographic time for the method is 8 minutes and, provided that information on the alcohol concentration and pH is readily available, the molecular and free sulfur dioxide concentrations for the sample can be rapidly calculated using simple formulae. The HS-GC method offers a high degree of precision, with a reported coefficient of variation of 3.72%. Comparisons with standard A/O and Ripper results on a large set of wine samples showed large discrepancies for those wines with high anthocyanin levels, suggesting that SO2 bound to anthocyanins is released during those procedures, inflating the amount of free SO2 that is actually available to protect the wine. The characteristics of rapid analysis, good sensitivity, and high precision, demonstrate that the method could be applicable in a production environment, albeit a large scale operation where a Gas Chromatograph could be utilized and maintained.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2019-09-06 15:44:542019-09-06 15:44:54Rapid Determination of Molecular and “Truly Free” Sulfur Dioxide by Headspace Gas Chromatography