ABSTRACT
An extraction method, using a mixed solvent, has been developed for the identification of semivolatile organic compounds (SVOCs) associated with airborne particles. The procedure yields a single extract, suitable for gas chromatographic analysis, that contains both polar and nonpolar compounds. The solvent is a one-to-one mixture of cyclohexane and 1-chlorobutane. The liquids are miscible and have virtually identical boiling points, which permits refluxing as well as evaporative concentration. The extraction procedure, followed by gas chromatograph/mass spectrometer (GC/MS) analysis, has been used to examine SVOCs associated with size-fractionated airborne particles. The particles were collected indoors and outdoors, for a 6-week period, at a site in Neenah, Wisconsin. The procedure adequately extracts the major organic compounds associated with these particles. The results indicate that there are strong indoor sources for certain branched and n-alkanes, fatty acids, and phthalate esters at the Neenah site. It is also apparent that the organic compounds associated with indoor coarse particles have indoor sources. This study reaffirms the earlier observation that partitioning between the vapor phase and the surface of airborne particles is more pronounced indoors than outdoors.
