Ethylene Oxide and 2-Chloroethanol Analysis in Instant Noodles by Dynamic Headspace and GC- MS/MS

Importance of the Topic

The analysis of ethylene oxide and its metabolite 2-chloroethanol in food products is essential for ensuring consumer safety and meeting regulatory limits. Ethylene oxide has been used as a fumigant pesticide and poses carcinogenic risk if inhaled. Its residue and that of 2-chloroethanol must be controlled below strict maximum levels in foods such as instant noodles.

Objectives and Study Overview

This study describes the development and validation of a fast and sensitive method for the quantitation of ethylene oxide and 2-chloroethanol in various components of instant noodle products. The aim is to achieve reliable recovery and linearity without requiring matrix matched calibration curves.

Methodology and Instrumentation

A dynamic headspace trapping approach was coupled to GC-MS/MS for sample analysis. Key methodological points include:

• Direct sample introduction via a headspace autosampler using a cooled absorbent trap to concentrate volatiles.
• Thermal desorption of analytes into the GC inlet for separation.
• Use of isotopically labeled internal standards to correct for variability and achieve accurate quantitation.

Used Instrumentation

• GCMS TQ8050 NX triple quadrupole mass spectrometer equipped with patented ion source technology for ultratrace sensitivity.
• HS-20 NX headspace autosampler with trap module capable of dynamic headspace operation.
• Capillary column SH-I-624 Sil MS with 60 meter length, 0.25 mm internal diameter and 1.4 µm film thickness.

Main Results and Discussion

The method delivered excellent linearity for both analytes over the range of 5 to 100 ng per gram, with R2 values exceeding 0.999. The limit of quantitation was established at 5 ng per gram based on signal-to-noise ratios above ten. Repeatability tests showed relative standard deviations under ten percent at the LOQ level. Recovery experiments in four types of instant noodles and their seasoning components yielded results within the acceptable range of 70 to 130 percent when spiked at 10 ng per gram.

The addition of magnesium sulfate to samples with high water content improved peak shape and sensitivity for 2-chloroethanol by reducing peak broadening. This step is recommended for aqueous-rich ingredients to maintain method performance.

Benefits and Practical Application of the Method

• Streamlined sample preparation without extensive manual extraction or clean up.
• High sensitivity and selectivity for trace level monitoring in complex food matrices.
• Use of internal standard calibration eliminates the need for matrix matched curves in many cases.
• Applicability to a wide range of product types including noodles, seasoning powders, oils and sauces.

Future Trends and Potential Applications

Advances in headspace technology and MS instrumentation may further lower detection limits and reduce analysis time. Automation of sample handling and integration with digital data workflows will enhance throughput in quality control laboratories. The approach can be extended to other volatile contaminants and applied to additional food and environmental matrices. Continued refinement of calibration strategies may allow single point calibration for broader sample sets.

Conclusion

A robust dynamic headspace GC-MS/MS method with isotopic internal standards was established for the determination of ethylene oxide and 2-chloroethanol in instant noodles. The approach achieved excellent sensitivity, linearity and recovery without extensive matrix matched calibration, facilitating routine compliance testing and consumer safety assurance.

References

1. United States Environmental Protection Agency Ethylene Oxide accessed 18 December 2023 https colon slash slash www dot epa dot gov slash sites slash default slash files slash 2016-09 slash documents slash ethylene-oxide pdf
2. European Commission Summary of the Meeting on Ethylene Oxide ETO Regulatory and Technical Aspects accessed 18 December 2023 https colon slash slash food dot ec europa eu slash system slash files slash 2021-12 slash rasff_ethylene-oxide-incident_e410_crisis-coord_20211004_sum pdf
3. Shimadzu Application Databook SAIP-GC001-APDB001 Analysis of Ethylene Oxide amp 2-Chloro Ethanol Application Databook accessed 18 December 2023 https colon slash slash www dot an dot shimadzu dot com slash rs slash 119-VAD-470 slash images slash EtO percent20Analysis pdf