Novel family of multi-layer cartridges filled with a new carbon adsorbent for the quantitative determination of volatile organic compounds in the atmosphere

The ability of a new graphitized carbon black adsorbent (Carbograph 5) to r etain volatile organic compounds (VOCs) in air has been investigated throug h laboratory experiments performed by frontal chromatography. An artificial mixture containing 19 different compounds from C-1 to C-7 at levels of 50 ppb (v/v) each was used as eluent. The amounts of VOCs retained by Carbogra ph 5 were determined by high-resolution GC-flame ionization detection after thermal desorption at 250 degrees C. The retention features of this adsorb ent were compared with those provided by Carbograph 1 and Carbograph 2, two graphitic carbons equivalent in specific surface area and adsorption prope rties to Carbopack B and Carbopack C, respectively. It was found that Carbo graph 5 exhibits safe sampling volumes of VOCs much higher than those of Ca rbograph 1 and is the only hydrophobic material providing performances comp arable to those of some molecular sieve adsorbents. Results obtained indica te that Carbograph 5 can be used alone or in combination with other materia ls. When combined with lighter adsorbents, it allows the quantitative colle ction of polar and non-polar VOCs with carbon number higher than 3 in air v olumes larger than 51 at any relative humidity. In combination with stronge r carbon molecular sieve adsorbents, it makes possible the quantitative col lection of components with volatilities ranging from C-2 to C-7 in small sa mples. (C) 1999 Elsevier Science B.V. All rights reserved.