Characterization of sorption mechanisms of solid-phase microextraction with volatile organic compounds in air samples using a linear solvation energy relationship approach

The linear solvation energy relationship (LSER) model was used to characterize interactions responsible for sorption of volatile organic compounds (VOCs) in air samples on six different solid-phase microextraction (SPME) fibers at 296K and zero relative humidity. The polydimethylsiloxane and polyacrylate fibers sorption data were also modeled at different relative humidities in the range of 10-90% and influence of water vapors on the extraction process is discussed. The LSER equations were obtained by a multiple regression of the distribution coefficients of 14 probe solutes on an appropriate SPME fiber against the solvation parameters of the solutes. The derived LSER equations successfully predicted the VOC distribution coefficients and the selectivity of individual SPME fibers for the various volatile solutes. The LSER approach coupled with SPME is a relatively simple and reliable tool to rapidly characterize the sorption mechanism of VOCs with various stationary phases and may potentially be applied to design and test new chromatographic materials for sampling or separation of VOCs.