Sampling and analysis of organic solvent vapours--with special reference to sampling tubes for a short time and for...

The present paper concerns the sampling and analysis of organic solvent vapours for a short period of time and for the working period. Porous polymer beads, Porapak Q, was applied to the adsorbent of the sampling tube for mixed vapours of aromatic compounds (benzene, toluene and xylenes). The adsorbent was packed in stainless steel column of a suitable size, and the adsorbed vapours were released by heating in the flasher then analysed by gas chromatography. The concentrations of the mixed vapours could be measured simultaneously with sufficient recoveries at the ordinary concentrations in the working yeard. The sampling conditions by pumps and the practical recoveries were tested. Being sucked with the vacuum pump using a Gastek detection tube (100 ml), the recoveries proved to be almost 100%. Being sucked with portable diaphragmatic pumps at a slow flow rate (22 ml/min), the recoveries were constant with only small variations. At a relatively fast flow rate (220-230 ml/min), the recoveries were not so high as those at the slow flow rate. These findings indicate that the sampling tube with Porapak Q is useful for aromatic compounds not only as a room air sampler for a short period of time but also as a personal air sampler.