Study of preservation of polydimethylsiloxane/Carboxen solid-phase microextraction fibres before and after sampling of volatile organic compounds in indoor air

Solid-phase microextraction (SPME) was applied to the on-site analysis of volatile organic compounds (VOCs) in indoor air. The compounds were at trace levels, which complicates analysis and also sample storage. Fibre storage before and after sampling was studied. Several tests were performed, and the best results were obtained for a home-made storage assembly. To avoid contamination by acetone and acetaldehyde, activated carbon was added in the storage housing. Under these conditions, fibres can be stored up to 2 days before use. After sampling, storage of 10 VOCs was evaluated by varying air relative humidity of the air. This parameter was shown to be insignificant for 3 storage days: recoveries for acetaldehyde and acetone were 149 and 176%, respectively, and ranged from 95 to 107% for the other VOCs investigated.