Passive sampling of ambient ozone by solid phase microextraction with on-fiber derivatization

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Air Quality Monitoring

Background:

• Ozone is a significant air pollutant impacting human health and ecosystems.
• Accurate monitoring of ambient ozone levels is crucial for exposure assessment.
• Existing ozone monitoring methods can be complex or lack sensitivity.

Purpose of the Study:

• To develop and validate a convenient and sensitive passive sampler for ambient ozone.
• To utilize solid phase microextraction (SPME) with a functionalized fiber for ozone capture.
• To establish a reliable method for ozone exposure assessment.

Main Methods:

• A solid phase microextraction (SPME) device with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was employed as a passive sampler.
• The fiber was pre-loaded with O-2,3,4,5,6-(pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) and 1,2-di-(4-pyridyl)ethylene (DPE).
• Ozone reacted with DPE to form pyriden-4-aldehyde, which then derivatized with PFBHA. Derivatives were analyzed using portable gas chromatography with an electron capture detector.

Main Results:

• The SPME passive sampler demonstrated an experimental sampling rate of 1.10 x 10(-4) cm(3) s(-1).
• The detection limit for ozone was determined to be 58.8 microg m(-3) h(-1).
• Field validations showed high correlation (r=0.9837) with a direct-reading ozone monitor.

Conclusions:

• The developed SPME passive sampler is a convenient and sensitive tool for ambient ozone exposure assessment.
• This method offers a viable alternative to existing ozone monitoring techniques.
• The sampler's performance was validated in both laboratory and field settings.