Detection of Cork Taint Fault in Wine Using HS-SPME and GC-TOFMS for the Quantification of 2,4,6-trichloroanisole

Importance of the topic

Small amounts of 2,4,6-trichloroanisole (TCA) migrating from natural cork can spoil wine by introducing a musty off-flavour known as cork taint. The human sensory threshold for TCA is in the low parts-per-trillion range, so sensitive and reliable analytical methods are essential for quality control in the wine industry.

Objectives and Study Overview

This study evaluates a headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography time-of-flight mass spectrometry (GC-TOFMS) approach for the calibration and quantification of TCA in wine. Key aims include demonstrating low-level detection, calibration linearity, and robustness against matrix interferences.

Methodology and Instrumentation

Wine samples (10 mL) were spiked with TCA at concentrations from 5 ppt to 10 ppb and mixed with 3 g salt in 20 mL vials. Samples were incubated at 65 °C for 5 minutes, and analytes were extracted for 30 minutes using a 2 cm DVB/CAR/PDMS SPME fiber. GC separation employed an Rxi-5ms column with a temperature program from 40 °C to 300 °C, and TOFMS data were acquired over 33–500 m/z at 15 spectra/s.

Instrumentation

• HS-SPME fiber: 2 cm DVB/CAR/PDMS (Sigma Aldrich)
• GC: Agilent 7890 with MPS2 autosampler
• MS: LECO Pegasus HT TOFMS with ChromaTOF deconvolution software
• Carrier gas: He at 1 mL/min
• Injection: 2 min splitless desorption at 250 °C

Key Results and Discussion

A calibration curve from 5 ppt to 10 ppb yielded excellent linearity (R² = 0.9999). The full-scan TOFMS and ChromaTOF deconvolution effectively separated TCA from coeluting matrix components across a wide range of signal-to-noise ratios. Application of the calibration to a 50 ppt test sample produced a quantitation error of 7.8 %, demonstrating accuracy at sensory-relevant levels.

Benefits and Practical Applications

• Low-ppt detection of TCA without selected ion monitoring.
• Simultaneous full-scan profiling of other volatile compounds in wine.
• Automated deconvolution ensures reliable quantitation in complex matrices.
• Suitable for routine wine quality control and cork screening.

Future Trends and Applications

Advances in high-resolution mass spectrometry, automated data processing, and miniaturized sampling devices promise even greater sensitivity and throughput. Integration with real-time monitoring and predictive analytics could further enhance wine quality assurance and fault prediction.

Conclusion

The HS-SPME GC-TOFMS method with advanced deconvolution provides sensitive, accurate quantification of TCA at ppt levels in wine, overcoming matrix interferences and offering comprehensive volatile profiling in a single analysis. Its robustness and reliability make it a valuable tool for the wine industry’s quality control efforts.