The Utility of Porous Polymer Sorbents in Chemically-Active Environments

Porous polymer adsorbents used for combustion source sampling have the potential for alteration by reacting with components of the stream being sampled. Two potential problems, alteration of capacity and selectivity by sulfonation and nitration and the creation of a thermally-induced blank are examined in this report. The effect of sulfonation and nitration on the porous polymers Tenax-GC and XAD-2 was examined by gas-solid chromatography. Variation in capacity and selectivity between native and altered sorbents was determined by construction of plots of log V k versus 1/T × 1000. A series of five solutes representing a range of polarities was used. Surface area measurements were used in conjunction with these plots to make generalizations about the potential effects of alteration of the sorbents. The thermal blank from XAD-2 resin was examined by using the resin in a simulated sampling scheme where the resin temperature was varied. The XAD-2 was then carried through a standard workup procedure designed to characterize collected components. Specific components were identified by GC/MS.