Determination of Ethylene Oxide and Ethylene Chlorohydrin in Medical Devices using the Agilent 8890 GC and 7697A Headspace Sampler

Significance of the Topic

Sterilization of medical devices using ethylene oxide is common due to broad material compatibility
The presence of residual ethylene oxide and ethylene chlorohydrin poses health risks and requires stringent monitoring
International and national standards define allowable limits ensuring patient safety and regulatory compliance
Monitoring these residues supports quality control and risk assessment in medical device manufacturing

Objectives and Study Overview

This study presents a method for simultaneous determination of ethylene oxide and ethylene chlorohydrin in medical devices
The method follows GB T 14233 1 standard and evaluates performance of an Agilent 8890 gas chromatograph with 7697A headspace sampler
Key goals include achieving high sensitivity repeatability and linearity within relevant concentration ranges

Methodology

Samples and calibration standards were prepared in water with concentrations from 1 to 20 mgL for ethylene oxide and 2 to 40 mgL for ethylene chlorohydrin
Headspace extraction at 60C oven temperature 90C loop temperature and 30 minute equilibration time
GC separation used a DB Select 624 UI column with temperature ramp from 40C to 130C at 15C per minute under constant nitrogen flow
Calibration curves employed five levels and method detection limits were calculated using signal to noise criteria

Instrument Used

Agilent 7697A headspace sampler with 1 mL loop split mode operation
Agilent 8890 gas chromatograph with splitsplitless inlet flame ionization detector and Ultra Inert DB Select 624 UI column 30 m mu m film thickness
Carrier and detector gases controlled for constant flow including air hydrogen and makeup gas

Main Results and Discussion

Clear chromatographic separation with ethylene oxide eluting at 2.3 minutes and ethylene chlorohydrin at 5.6 minutes
Calibration coefficients of determination exceeded 0.999 indicating excellent linearity for both analytes
Area precision RSD below 3.5 percent and retention time RSD below 0.014 percent across eight injections
Method detection limits established at 0.013 mgL for ethylene oxide and 0.11 mgL for ethylene chlorohydrin demonstrating high sensitivity

Benefits and Practical Applications

Reliable simultaneous quantification of two critical sterilization residues enhances laboratory efficiency
High reproducibility and sensitivity facilitate compliance with ISO and GB regulations for medical device safety
Water based sample preparation reduces interference and simplifies handling reducing potential for analyte loss

Future Trends and Possibilities

Integration of mass spectrometric detection for enhanced selectivity and lower detection limits
Automation of sample preparation and online headspace sampling to support process monitoring and quality control
Extension of the method to additional sterilant byproducts and adaptation to evolving regulatory requirements

Conclusion

The presented gas chromatographic headspace method demonstrates robust performance for simultaneous analysis of ethylene oxide and ethylene chlorohydrin
Excellent linearity sensitivity and precision confirm its suitability for routine quality control in medical device manufacturing

References

ISO 10993 7 2008 Part 7 Ethylene oxide sterilization residuals
GB T 16886 7 2001 Part 7 Ethylene oxide sterilization residuals ISO 10993 7 IDT
GB 19083 2010 Technical requirements for protective face masks in medical use
GB 19082 2009 Technical requirements for single use protective clothing for medical use
GB T 14233 1 2008 Test method for infusion transfusion injection equipment Part 1 Chemical analysis methods