Combination of porous membrane and FT-IR spectrometry for detection of chlorinated semivolatile compounds in soils

In this paper, a new method is reported for determining semivolatile aromat ic compounds in soils. Porous membranes were used as a sampling medium to a dsorb analytes that evaporated from soil samples. The adsorbed analytes wer e examined by Fourier-Transform infrared (FT IR) spectrometry in the transm ittance mode. To accelerate the speed of evaporation, the soil samples were heated to various temperatures, and to increase the adsorption efficiency, porous membranes were further coated with hydrophobic materials. Besides t he heating temperature and the properties of the coating materials, several other factors that influence the infrared signals were also examined. Thes e factors include moisture content, sampling time, coating thickness, volat ility, and concentration of analyte. Using optimal conditions, the detectio n limits for semivolatile aromatic compounds can be lower than 100 ng/g.