Implementation of Stir Bar Sorptive Extraction (SBSE) for the Analysis of Volatile Compounds in Tequila

Tequila has a particular aroma and taste that distinguishes it from other alcoholic beverages, giving it international appeal. Tequila's unique sensory attributes are the result of a particular and complex combination of several chemical compounds. Therefore, a high sensitivity chemical analysis has been developed to evaluate the composition of tequila. The technique of solid phase extraction with sorption bar (SBSE) coupled with gas chromatography from mass spectrometry is highly sensitive and has the ability to identify trace compounds that could serve as quality markers and help with authentication. The objective of this work was to implement the SBSE methodology in the analysis of the volatile composition of tequila. Best analysis conditions for the polydimethylsiloxane (PDMS) bar were defined as follows: 15 mL of a sample with 59% dilution of tequila in water, extraction for 140 min at 1200 rpm, a desorption temperature of 264 °C, and a cryogenic temperature of -124 °C. For the ethylene glycol/silicone (EG/Silicone) bar, best conditions were defined as: 15 mL of a sample with a 70% dilution of tequila in water, extraction for 85 min at 835 rpm, a desorption temperature of 220 °C, and a cryogenic temperature of -130 °C. Several tequila samples were analyzed in their different types (silver, gold, aged, extra aged, ultra aged, and mixed), along with other distilled agave alcoholic drinks. A total of 590 chemical compounds were found, which is the greatest number reported so far for tequila. Principal component analysis indicated that SBSE methodology can differentiate between tequila (and different tequila types) and other distilled agave beverages. In the future, this methodology may be used to develop authentication tests, and thus guarantee the quality and authenticity of tequila around the world.