Characterization of volatile organic compounds on airborne dust in a swine finishing barn

Three methods of extracting volatile organic compounds (VOCs) adsorbed on the airborne dust in a swine finishing building were investigated: solvent extraction using dichloromethane, solid-phase microextraction (SPME) using carboxen/polydimethylsiloxane (CAR/PDMS) and PDMS fibers, and purge and trap. Airborne dust was first collected in pre-baked glass-fiber filters and analyzed using each of the three methods. Solvent extraction with dichloromethane extracted only some high-boiling point carboxylic acids. The SPME CAR/PDMS fiber extracted the low- to mid-boiling point VOCs such as the carboxylic acids, phenols, and indoles; while the PDMS fiber extracted more of the mid-boiling point compounds, specifically the aliphatic hydrocarbons, indoles, and some aldehydes. The purge and trap method extracted compounds with low- to midboiling points including volatile carboxylic acids, aldehydes, alcohols, ketones, indoles, and esters. Quantitative analysis of five selected VOCs (i.e., acetic acid, propionic acid, butyric acid, hexanal, and nonanal) using the purge and trap method showed acetic acid as generally the most abundant and nonanal as the least abundant.