Eavaluation of automatic thermal desorption–capillary GC for determination of semivolatile organic compounds (SVOCS) in indoor air

Some data on a newly developed filter/sorbent indoor air SVOC sampling device for thermal desorption analyiss are described. Thermal desorption of SVOCs spiked on Tenax had reponse factors identical to on-column injection except for highly polar compounds like fatty acids. SVOCs spiked on quartz fiber filters had response factors that on an average were 80% of the on-column response factors (66% for oxygen containing compounds and 87% for non-oxygen compounds) Low nanogram on-tube amounts of SVOCs were found generally to have lower recoveries than larger amounts from both Tenax and quart fiber filters. This appeared to be explained in part by a relatively larger “memory” effect and lower desorption efficiency. In addition, it was indicated that the “memory” effect was an important source of background contaminations that might impair analysis of low nanogram on-tube amounts of some SVOCs. Polar SVOCs. Polar SVOCs in the gas phase appear to adsorbto the quartz fiber filters. This functions as a precleaning of the sample and thus minimizes the problem with coeluting peaks. The relative standard from nine duplicate samples appeared to be sufficiently low to distinguish a day variation.