Determination of odour-causing volatile organic compounds in cork stoppers by multiple headspace solid-phase...

Area of Science:

• Analytical Chemistry
• Food Science
• Environmental Science

Background:

• Cork taint compounds, including 2,4,6-trichloroanisole (2,4,6-TCA), guaiacol, 1-octen-3-ol, and 1-octen-3-one, negatively impact wine's organoleptic properties.
• Accurate quantification of these volatile organic compounds (VOCs) in cork stoppers is crucial for quality control in the wine industry.

Purpose of the Study:

• To develop and validate a sensitive analytical method for determining key cork taint compounds in cork stoppers.
• To optimize extraction parameters for enhanced detection of target VOCs.

Main Methods:

• Multiple headspace solid-phase microextraction (MHS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was employed.
• Optimization of variables including temperature, water addition, extraction time, and cork sample mass was performed.
• A specific 50/30 μm divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber was used for extraction.

Main Results:

• The MHS-SPME method achieved low limits of detection for 2,4,6-TCA (0.3 ng/g), guaiacol (7.5 ng/g), 1-octen-3-one (1.7 ng/g), and 1-octen-3-ol (1.9 ng/g).
• Relative standard deviation for replicate samples was consistently below 10%, indicating good reproducibility.
• Significant analyte losses were observed when cork samples were ground at room temperature, highlighting the importance of sample handling.

Conclusions:

• The developed MHS-SPME-GC-MS method is effective for the quantitative analysis of major cork taint compounds in cork stoppers.
• The method's performance was validated through recovery studies and comparison with Soxhlet extraction.
• Proper sample preparation is essential to avoid analyte loss and ensure accurate results.