Reliable analysis of ethylene oxide and 2-chloroethanol in food samples using gas chromatography mass spectrometry

Significance of the Topic

Ethylene oxide and its degradation product 2-chloroethanol are regulated contaminants in food that pose health risks. Sensitive, accurate and high-throughput methods are essential for compliance with EU maximum residue limits and for safeguarding public health.

Aims and Overview of the Study

This study demonstrates the performance of the Thermo Scientific TRACE 1610 GC system combined with the TSQ 9610 triple quadrupole GC-MS/MS for reliable analysis of ethylene oxide and 2-chloroethanol in diverse food matrices.

Methodology and Instrumentation

An aliquot of QuOil extract from food samples or acetonitrile standards was injected directly using a TRACE 1610 GC equipped with a TG 624 SilMS capillary column. The TSQ 9610 MS/MS employed an advanced AEI ion source with optimized parameters and XLXR detection. Key ion transitions were monitored for quantitation. Chromeleon 7.3.1 software was used for data acquisition and processing.

Main Results and Discussion

• Sensitivity and Linearity The method achieved quantitation limits at 0.002 mg/L (equivalent to 0.007 mg/kg) with a linear range up to 5 mg/L (16.5 mg/kg) and backcalculated deviations within ±20 percent.
• Selectivity Effective separation of ethylene oxide from acetaldehyde was obtained by the TG 624 column, avoiding interference in ion ratios.
• Robustness A continuous sequence of 230 injections over three days showed stable retention times (variation below 0.01 min) and area reproducibility (RSD < 9 percent) with no maintenance interventions.
• Real Samples Analysis No ethylene oxide residues were detected in ten representative food matrices. 2-Chloroethanol was quantified using both external and deuterated internal standards, with deviations under 20 percent compared to reference values.

Benefits and Practical Applications

• The low injection volume and high sensitivity reduce maintenance needs and sample preparation complexity.
• Broad linear dynamic range allows analysis of samples with high and low residue levels without reanalysis.
• The system is suitable for routine food safety laboratories requiring compliance with EU regulations and ISO/IEC 17025 accreditation.

Future Trends and Potential Applications

• Integration of automated sample handling and data processing to further increase laboratory throughput.
• Expansion of multi-residue methods to include additional volatile or semi-volatile contaminants.
• Development of compact or portable GC-MS/MS platforms for field or on-site screening.
• Advances in ion source technology to improve sensitivity and reduce matrix effects.

Conclusion

The combined TRACE 1610 GC and TSQ 9610 GC-MS/MS platform delivers sensitive, selective and robust analysis of ethylene oxide and 2-chloroethanol in food, meeting regulatory requirements and supporting high-throughput testing with minimal maintenance.

Reference

1. European Commission DG SANTE SANTE126822019 Analytical quality control and method validation procedures for pesticide residues analysis in food and feed
2. European Commission Implementing Regulation EU2015868 amending maximum residue levels for ethylene oxide and 2-chloroethanol in food
3. Thermo Fisher Scientific TRACE 1610 GC and TSQ 9610 MS/MS product documentation