Comparison of nutshell granular activated carbons to commercial adsorbentsfor the purge-and-trap gas chromatographic analysis of volatile organic compounds

Granular activated carbons (GACs) made from agricultural by-products were i nvestigated as adsorbents for short path thermal desorption gas chromatogra phic analysis of selected polar and nonpolar organic compounds. GACs made f rom macadamia nut, black walnut and hazelnut shells were compared to four c ommercially available adsorbents, namely, Tenax TA, Carboxen 569, Carbosiev e Sm and coconut charcoal for their properties in purge-and-trap analysis. Adsorption values and breakthrough volumes were calculated for compounds fr om C-3 and C-6-C-10. GACs derived from macadamia nut shells were found to a dsorb and desorb between 80% (benzene) and 277% (ethylbenzene) more acetone (C,), benzene (C,), toluene (C-7), ethyl- (C-8), n-propyl- (C-9), or sec.- butylbenzenes (C-10) purged from water at the 100 ppb level than the commer cial adsorbents tested. (C) 2000 Published by Elsevier Science B.V.