Anal. Chem. 1993, 65, 1758-1763
1758
Multiplex Gas Chromatography with a Hollow Fiber Membrane Interface for Determination of Trace Volatile Organic Compounds in Aqueous Samples Min J. Yang and Janusz Pawliszyn' The Guelph- Waterloo Centre for Graduate Work in Chemistry and the Waterloo Centre for Groundwater Research, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
A multiplex gas chromatographic technique was applied in conjunction with a hollow fiber membrane module to allow rapid routine analysis and long-termcontinuous monitoringof trace amounts of volatile organic compounds (VOCs)in aqueous samples. This solvent-free method of analysis substantiallyreduces the sample preparation time by eliminating the preconcentrationstep. Loss of VOCs was also minimized during the analytical process. The sensitivity of the analysis was greatly enhanced due to multiplex and throughput advantages. The hollow fiber extraction can be performed using two flow rate regimes. At low flow rates, quantitative extraction is ensured, hence the effects of temperature and matrix on recoveries areeliminated. For high flow rates, the sensitivity of the method is dramatically increased because of the increase in extraction rates. At the optimum flow rate,a detectionlimit of 4 bg/L, with a precision of
