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 organic compounds in air by membrane extraction followed by sorbent concentration and gas chromatographic separation is discussed. The device samples headspace and makes automatic injections followed by rapid separation and quantification. The main components of the system include membrane module, microtrap, and transfer line. A membrane module, microtrap, and fan are mounted in a housing, together constituting a MESI (membrane-extraction sorbent interface) sampling unit. A heated silicosteel capillary column was used as the transfer line, avoiding adsorption and condensation of analytes and performing separation of the analytes prior to detection. The device demonstrated potential for field monitoring of aromatic hydrocarbons, chlorinated compounds, and terpenoids. © 2001 John Wiley & Sons, Inc. Field Analyt Chem Technol 5: 69–74, 2001