Sample Preparation of Volatile Organic Compounds in Air Samples with a Novel Polyimide-Packed Cartridge Designed for the Subsequent Analysis in Capillary Gas Chromatography

Spherical polyimide particles have been synthesized as an extraction medium of volatile organic compounds (VOCs) in air samples. The polyimide was prepared with the starting materials of pyromellitic dianhydride (PMDA) and 4,4'-diaminodiphenyl ether (4,4'-oxydianiline, ODA), resulting spherical particles having an average diameter of about 5 mu m. Packed into a laboratory made mini-extraction tube, the synthesized PMDA-ODA particles were employed as the adsorbent for the subsequent analysis in capillary gas chromatography. The extraction capacities for acetone, hexane, toluene are 0.42, 0.24, 0.78 mu mol/g, respectively. The recoveries for these typical organic compounds are more than about 95%. The results clearly showed a good adsorption ability of the PMDA-ODA particles to typical VOCs frequently found in indoor environments, suggesting a future possibility to develop a more miniaturized sample preparation device specially-designed for on-site sampling of indoor air samples.