Evaluation of natural crab shell as an adsorbent for preconcentrating airborne volatile organic compounds collected in a canister

Abstract

A method has been developed for preconcentrating the volatile organic compounds (VOCs) in ambient air using a trap filled with natural crab shell powder without the need for extensive cryotrapping with liquid cryogens. Air samples collected in the canister were concentrated on the crab shell adsorbent trap without cryotrapping and then analysed using thermal desorption followed by capillary column (DB-5) gas chromatography with simultaneous ion trap mass detection. These analytical data on ambient air have been compared with those obtained by cryotrapping volatile compounds in glass beads followed by thermal desorption. The characteristics of natural crab shell as an adsorbent have been presented and its capacity for preconcentrating airborne VOCs has been tested by measuring breakthrough volume (l/g), detection limit (ppb, v/v) and reproducibility. The application of natural crab shell adsorbent trap for the analysis of ambient air samples collected in the canister has been proved to be useful. (C) 1998 Elsevier Science B.V. All rights reserved.