Analysis of Ethylene Oxide and 2-Chloroethanol in Food

Significance of the Topic

Ethylene oxide and 2-chloroethanol present severe health hazards and are strictly regulated due to carcinogenic and mutagenic properties. Historically used for fumigating food commodities, EtO can react within complex matrices to form toxic by-products. The European Union has banned its use in food disinfection and set maximum residue limits (MRLs) between 0.02 and 0.10 mg/kg. Recent recalls underline the importance of sensitive analytical methods to protect public health and ensure compliance.

Study Objectives and Overview

This summary outlines the development and validation of GC-MS/MS protocols aimed at trace-level quantification of EtO and 2-CE in diverse food matrices, including sesame seeds, chili powder, and instant noodles. The objectives are to achieve low limits of quantitation, high reproducibility, and adherence to EU MRLs to support routine surveillance and quality control.

Methodology and Instrumentation

• Sample preparation: QuEChERS extraction, direct headspace vial analysis, and EtO-to-2-CE conversion approaches.
• Injection modes: liquid injection and dynamic headspace sampling for simultaneous or selective determination.
• Analytical optimization: multiple reaction monitoring (MRM) transitions, column selection, electron ionization parameters, and calibration strategies.

Used Instrumentation

• GCMS-TQ8050 NX and GCMS-TQ8040 NX triple quadrupole GC-MS systems
• Auto injectors and samplers: AOC-20i/s, AOC-30i, AOC-20s
• Dynamic headspace module: HS-20 NX
• Capillary columns: SH-RTX-VMS and SH-Stabilwax DA

Main Results and Discussion

• Limits of quantitation as low as 2.5 ppb on column (5–10 ppb in sample) for both EtO and 2-CE.
• Linearity demonstrated by r² values exceeding 0.995 across relevant concentration ranges.
• Precision shown by relative standard deviations below 10% in spiked matrices.
• Recovery rates between 90% and 105% confirm method accuracy in complex food samples.

Benefits and Practical Applications

• Simplified workflows eliminate derivatization and reduce sample preparation time and cost.
• High throughput capabilities support large-scale monitoring under food safety programs.
• Validated methods meet or exceed regulatory sensitivity and precision requirements for routine QA/QC.

Future Trends and Applications

• Adoption of high-resolution mass spectrometry for comprehensive residue screening.
• Enhanced automation and robotics to boost sample throughput and reduce manual intervention.
• Integration of AI-driven data analysis for robust peak identification and quality assurance.
• Expansion to multi-residue methods encompassing additional volatile contaminants.

Conclusion

Robust GC-MS/MS protocols employing liquid injection, dynamic headspace, and conversion strategies deliver sensitive, precise, and efficient quantification of EtO and 2-CE in food products. These validated methods enable laboratories to comply with EU regulations and strengthen food safety controls across a range of matrices.

References

• EURL-SRM Analytical Observations Report on Ethylene Oxide and 2-Chloroethanol
• Commission Regulation (EU) 2015/868 on maximum residue limits for EtO and metabolites
• European Chemicals Agency classification of Ethylene Oxide, 2020