Abstract
Coconut-shell activated carbon is the sorbent of choice in sample tubes for collecting the majority of organic compounds present in workplace atmospheres. However, the surface characteristics of coconut carbon are not well suited to the sampling of certain polar and reactive compounds. Two new sorbents are described and evaluated experimentally to determine whether they are suitable for sampling acetone and 2-butanone. Anasorb 747 is a proprietary, synthetic, beaded active carbon. Sample capacity, desorption efficiency, and storage stability were found to be acceptable in the case of 2-butanone. Good results were also obtained with acetone, except that adsorbed sample was found to migrate between front and rear sections of the tube. Anasorb CMS is a carbon molecular sieve derived from Saran-type precursors. Sample capacity, desorption efficiency, and storage stability were found to be acceptable in the case of both acetone and 2-butanone. In general, the experimental results fit existing theories of adsorption and desorption well. No justification could be found for the use of anhydrous magnesium sulfate as a dessicant in the desorption step of analysis of either sorbent. Harper, M.; Kimberland, M.L.; Orr, R.J.; Guild, L.V.: An Evaluation of Sorbents for Sampling Ketones in Workplace Air. 8(4):293-304; 1993.