E-mail: ydkim91@skku.eduReceived March 3, 2013, Accepted April 1, 2013Aim of our study is finding adsorbents suitable for pre-concentration of chemical warfare agents (CWAs). Weconsidered Tenax, bare silica and polydimethylsiloxane (PDMS)-coated silica as adsorbents for dimethylmethylphosphonate (DMMP) and dipropylene glycol methyl ether (DPGME). Tenax showed lower thermalstability, and therefore, desorption of CWA simulants and decomposition of Tenax took place simultaneously.Silica-based adsorbents showed higher thermal stabilities than Tenax. A drawback of silica was that adsorptionof CWA simulant (DMMP) was significantly reduced by pre-treatment of the adsorbents with humid air. In thecase of PDMS-coated silica, influence of humidity for CWA simulant adsorption was less pronounced due tothe hydrophobic nature of PDMS-coating. We propose that PDMS-coated silica can be of potential importanceas adsorbent of CWAs for their pre-concentration, which can facilitate detection of these CWAs.Key Words : Chemical warfare agents (CWAs), Pre-concentration, Polydimethylsiloxane (PDMS)-coating,SilicaIntroductionDetection of ultralow concentration of chemical warfareagents (CWAs) has been attracting attention recently indefense development. CWAs with high vapor pressure canbe easily spread out in the atmosphere, and therefore, detec-tion of low-concentration of CWAs can allow initiation ofprotection process from CWAs as early as possible, ultimate-ly hindering diffusion of CWAs into a wider area.For detection of CWAs, ion mobility spectroscopy, gaschromatography and mass spectrometry can be used.