Trapping efficiency of aqueous pollutants in multichannel thick-film silicone-rubber traps for capillary gas chromatography

Established standard methods for analysing aqueous pollutants by capillary gas chromatography are cumbersome, time-consuming and expensive. With the a im of replacing the sample preparation procedures with direct concentrating and thermal desorption steps multichannel silicone-rubber traps were teste d to determine breakthrough volumes and optimum accumulation conditions as a function of water flow-rate. Larger multichannel traps, consisting of 32 silicone tubes in parallel were made to increase the collection flow-rate t hrough the trap with the same extraction efficiency of the initial smaller traps. It was shown that by increasing the number of parallel silicone tube s in the multichannel trap the breakthrough volume of benzene is 37 ml at a flow-rate of 75 mu l/min and the trap displays 11 theoretical plates under these conditions. (C) 1999 Published by Elsevier Science B.V. All rights r eserved.