Air sampling with porous solid-phase microextraction fibers

A new, rapid air sampling/sample preparation methodology was investigated u sing adsorptive solid-phase microextraction (SPME) fiber coatings and noneq uilibrium conditions for volatile organic compounds (VOCs), This method is the fastest extraction technique for air sampling at typical airborne VOC c oncentrations. A theoretical model for the extraction was formulated based on the diffusion through the interface between the sampled (bulk) air and t he SPME coating Parameters that affect the extraction process including sam pling time, air velocity, air temperature, and relative humidity were inves tigated with the porous (solid) PDMS/DVB and Carboxen/PDMS coatings. Very s hort sampling times from 5 s to 1 min were used to minimize the effects of competitive adsorption and to calibrate the extraction process in the initi al linear extraction region. The predicted amounts of extracted mass compar ed well with the measured amounts of target VOCs. Findings presented in thi s study extend the existing fundamental knowledge related to sampling/sampl e preparation with SPME, thereby enabling the development of new sampling d evices for the rapid sampling of air, headspace, water, and soil.