Advancements in Noninvasive Volatile Organic Compound Detection: Integrating Stirling Cooling Preconcentration with...

Area of Science:

• Analytical Chemistry
• Environmental Health
• Biomedical Diagnostics

Background:

• Volatile organic compounds (VOCs) in exhaled breath are key biomarkers for noninvasive disease diagnosis and exposure monitoring.
• Traditional thermal desorption (TD) tubes for VOC analysis face challenges with water vapor interference and selective adsorption.

Purpose of the Study:

• To develop and validate a novel preconcentration technique for simultaneous detection of 116 VOCs in exhaled breath.
• To overcome the limitations of existing methods, particularly water vapor interference and selective adsorption.

Main Methods:

• Combined Stirling cooling preconcentration with gas chromatography-flame ionization detector/mass spectrometry (GC-FID/MS) and SUMMA canisters.
• Utilized nitrogen pressurization for gas dilution and developed calibration curves for quantification.
• Analyzed exhaled breath samples from eight healthy subjects for method validation.

Main Results:

• Achieved simultaneous detection of 116 VOCs without refrigerants.
• Effectively addressed water vapor interference and selective adsorption issues.
• Demonstrated high linearity (R² > 0.998), low limits of detection (0.01–0.09 ppbv) and quantification (0.03–0.35 ppbv), and good precision (<20%) and accuracy (70–130%).

Conclusions:

• The developed Stirling cooling method offers a refrigerant-free, robust solution for accurate VOC quantification in exhaled breath.
• Provides significant technical support for noninvasive disease diagnosis and human exposure monitoring through breath analysis.