Design of continuous-monitoring device based on membrane extraction with sorbent interface and micro-gas chromatograph

A device for the continuous monitoring of the volatile and semivolatile org anic compounds in air by membrane extraction followed by sorbent concentrat ion and gas chromatographic separation is discussed. The device samples hea dspace and makes automatic injections followed by rapid separation and quan tification, The main components of the system include membrane module, micr otrap, and transfer line, A membrane module, microtrap, and fan are mounted in a housing, together constituting a MESI (membrane-extraction sorbent in terface) sampling unit. A heated silicosteel capillary column was used as t he transfer line, avoiding adsorption and condensation of analytes and perf orming separation of the analytes prior to detection. The device demonstrat ed potential for field monitoring of aromatic hydrocarbons, chlorinated com pounds, and terpenoids, (C) 2001 John Wiley & Sons, Inc.