Gas-solid retention volumes of organic compounds on styrene-divinylbenzene and ethylvinylbenzene-divinylbenzene co-polymer sorbent beads

Reliable gas sampling with a sorbent requires a good knowledge of the gas-solid retention volumes of the analytes on the sorbent. Literature data on specific retention volumes at 20 degrees C (V-g,V-293, 1/g) are reviewed for a number of styrene-divinylbenzene (Sty-DVB) and ethylvinylbenzene-divinylbenzene (EVB-DVB) sorbents, namely XAD-2, Porapak P, Porapak Q, Chromosorb 101, and Chromosorb 102. New measurements are also made by gas-solid chromatography for a Sty-DVB polymer employed in one variety of Empore membrane extraction filters. For all of the data, the log V-g,V-293 values are highly correlated with both log p(L)(0) (log of the liquid vapor pressure at 20 degrees C) and with T-b (pure compound boiling point, K). The correlation equations allow the prediction of log V-g,V-293 based on either log p(L)(0) or T-b. Equations that can be used for a wide range of compounds and a range of Sty-DVB and EVB-DVB sorbents are: log V-g,V-293=-1.16 log p(L)(0) + 3.51, and log Vg,293 = 0.0227T(b) - 6.60. Separate equatins are recommended for aliphatic acids and alcohols. For the Sty-DVB beads used in one variety of Empore extraction filters, the correlation equations are log V-g,V-293 = - 0.99 log p(L)(0) + 3.04, and log V-g,V-293 = 0.0175T(b) - 4.97. Most of the available data support absorption into the resin matrix as the dominant gas-solid partitioning mechanism for organic analytes to Sty-DVB sorbent materials.