Analysis of Trichloroanisole in Wine and Cork using a Purge and Trap Multimatrix Autosampler

Significance of the Topic

2,4,6-trichloroanisole (TCA) causes “cork taint” due to its extremely low odor threshold. Even trace ppt-level contamination can spoil wine aroma and consumer perception, highlighting the need for highly sensitive analytical methods.

Objectives and Study Overview

This study demonstrates an automated purge and trap approach to quantify TCA in wine and cork at part-per-trillion levels. Using in-vial purging and full sample preparation automation, the protocol aims to deliver high sensitivity, precision, and throughput.

Methodology and Instrumentation

Samples were purged with helium in sealed vials, concentrating volatile analytes onto a Tenax sorbent trap. The trap was thermally desorbed into an Agilent 7890A/5975 GC-MS operating in Selective Ion Monitoring (SIM) mode. Calibration standards (1–100 ppt) were prepared in 10% NaCl solution with an isopropylmethoxypyrazine internal standard.

• Sample Preparation: Teledyne Tekmar Atomx Automated VOC Sample Prep System with in-vial purge
• Sorbent Trap: Tenax (#1)
• Gas Chromatography: J&W DB-624 column (20 m × 0.18 mm × 1.0 µm)
• Detection: Agilent 5975C MSD in SIM mode (key ions: 95, 107, 112, 124, 125, 137, 151, 152, 195, 197, 212)

Key Findings and Discussion

The method achieved excellent linearity (r² = 0.9996), a method detection limit of 0.13 ppt, and precision with %RSD ≤ 8.4%. Carryover was below 0.6%. In real samples, no TCA was detected in tested wines, while corks contained TCA in the ppt range (e.g., 36.3 ppt in 1 g cork, equivalent to 181.4 ppt after dilution). Matrix spikes at 50 ppt in wine yielded recoveries between 90 % and 110 %.

Benefits and Practical Applications

Full automation minimizes manual handling, reduces matrix interferences from challenging wine and cork substrates, and accelerates sample throughput. The sensitive, reliable workflow supports routine quality control and screening for cork taint in the wine industry.

Future Trends and Potential Applications

Advancements could include multi-analyte detection, integration with high-resolution mass spectrometry for lower detection limits, and extension to other beverage and packaging materials. Coupling with advanced data analytics and remote monitoring may further optimize quality assurance processes.

Conclusion

The automated in-vial purge and trap method reliably detects TCA at part-per-trillion concentrations without sacrificing accuracy or efficiency, offering a robust solution for monitoring cork taint in wine production.

References

• Alvarez-Rodriguez, A. et al. Cork Taint of Wines: Role of Filamentous Fungi in TCA Formation. Applied and Environmental Microbiology, Dec 2002.
• United States Environmental Protection Agency. 2,4,6-Trichlorophenol, Jan 2000.