Differentiation of Fresh and Oxidized Wine Samples with HS-SPME, GC-TOFMS, and GC×GC-TOFMS

DOCUMENT: Application | Ref: 203-821-514Download
Category: Aroma Flavour Fragrance, Separation Science Mass Spectrometry

Pegasus HT and Pegasus 4D systems were used to differentiate two wine samples namely one fresh and one oxidized by the presence of oxygen inside the bottle. Thanks to the increased peak capacity and sensitivity offered by the coupling of a secondary column on the GCXGC system, it was possible to assign correctly the components formed during the oxidation process. Furthermore, LECO’s Deconvolution tool allowed the correct identification of the components well resolved or masked from the sample matrix. Ref. 203-821-514

Chemical analysis of the aromas associated with wine provides useful information for understanding the quality of the product and/or the process adopted for its production. Proper storage and the impact of the introduction of oxygen to a wine sample were investigated in this application note. Two bottles of wine, one stored properly and one that was intentionally oxidized from improper storage were chemically compared. Headspace solid-phase micro-extraction (HS-SPME) was exploited as sample preparation method paired with both GC-TOFMS and GCXGC-TOFMS for the complete separation and identification of both samples. Both approaches provided information on a number of volatile and semi-volatile analytes that contribute to the taste and aroma of the wine including, esters, carboxylic acids, alcohols, lactones, aromatics (hydrocarbons, phenols, aldehydes, etc.), and various sulfur-containing analytes. This study demonstrates LECO’s analytical platform and data analysis tools to differentiate and distinguish related samples. Fresh and oxidized wine samples were analyzed and appeared quite similar based on the TIC view. Nonetheless, peak finding and deconvolution uncovered specific analytes that differed between the samples that were not apparent in the TIC. The further addition of GC×GC uncovered specific analytes that differed between fresh and oxidized that were either below the S/N threshold or confounded by coelutions in the 1D data. Ref. 203-821-514