Speakers
Description
Air pollution by diverse organic compounds poses environmental and human health concerns, while personal exposure monitoring remains challenging. Conventional air sampling often relies on sorbents such as polyurethane foam (PUF) and synthetic polymers, which may have limitations related to cost, stability, and chemical interferences. Silicone-based materials offer a promising alternative due to their affinity for a broad range of organic compounds.
In this study, silicone (polydimethylsiloxane, PDMS) foam was prepared and evaluated as a low-cost sorbent for active and personal passive air sampling. PDMS foam was prepared from a two-component silicone elastomer system (elastomer/curing agent, 10:1) using sieved NaCl to generate the porous structure followed by curing and salt removal, and characterized by infrared spectroscopy. Extraction with ethyl acetate was optimized using ultrasound-assisted and Soxhlet procedures, yielding recoveries of 70–123% and 69–129%, respectively.
The prepared PDMS foam was successfully applied for active air sampling (4 L/min, 24 h) enabling the detection of 20 organochlorine compounds at concentrations of 0.91–531 pg/m3 air. In addition, to test its suitability as a personal passive air sampler, seven PDMS samplers were worn by participants in Skopje for 9 days and analyzed by GC-ECD and GC-MS following ultrasound-assisted extraction. 14 organochlorine compounds were identified by GC-ECD, including chlorobenzenes (7), HCH isomers (3), other organochlorine pesticides (2), and PCBs (2). 1,3,5-Trichlorobenzene, tetrachlorobenzene isomers, penta¬chlo¬robenzene, and PCB 180 were most frequently detected with normalized concentrations from 1.4 to 41.1 ng/g sampler. In addition, 13 of 16 target polycyclic aromatic hydrocarbons (PAHs) were detected, individual amounts ranging from 0.16 to 29.72 ng/g sampler. Fluorene, phenanthrene, chrysene, and benzo[k]fluoranthene showed the highest concentrations, reflecting combustion-related and urban sources, including traffic and tobacco smoke, as well as indoor activities such as cooking. Additionally, a diverse range of 45 other organic compounds were detected, including aliphatic and aromatic hydrocarbons, esters, oxygenated compounds, terpenes, fragrances, phthalates/plasticizers, and UV filters. Overall, these findings demonstrate the potential of PDMS foam for both active and personal passive air sampling of diverse organic compounds.
Keywords: silicone foam, air pollution, air sampling, passive sampler, GC-ECD, GC-MS