Passive sampling to control air quality in schools: Uptake rate determination and application

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Volatile organic compounds (VOCs) impact indoor air quality, especially in educational settings.
• Accurate monitoring of VOCs is crucial for understanding exposure risks.

Purpose of the Study:

• To apply passive sampling with TD-GC-MS for VOC determination in school environments.
• To quantify VOC concentrations in indoor and outdoor school settings.
• To establish experimental diffusive uptake rates for indoor VOC monitoring.

Main Methods:

• Passive sampling using Carbopack X tubes.
• Thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) for analysis.
• Parallel passive and active sampling to determine diffusive uptake rates.

Main Results:

• Experimental diffusive uptake rates ranged from 0.38 to 0.95 mL min⁻¹, with <5% RSD for 44 VOCs.
• Ethanol and isopropyl alcohol were prevalent indoors (23.84–83.16 µg m⁻³ and 5.42–25.92 µg m⁻³, respectively), linked to cleaning products.
• i-pentane and n-pentane were highest outdoors, correlating with traffic emissions.

Conclusions:

• Passive sampling with TD-GC-MS is effective for VOC monitoring in schools.
• Cleaning products are a significant source of indoor VOCs.
• Outdoor VOCs at schools are influenced by vehicular traffic.