Complementarity of purge-and-trap and head-space capillary gas chromatographic methods for determination of methyl-tert.-butyl ether in water

Abstract

Abstract An improved method has been developed for the quantitative determination of traces of methyl-tert.-butyl ether (MTBE) over a large range of concentrations in water samples based on two complementary techniques: head-space capillary gas chromatography and purge-and-trap gas chromatography. The interesting aspect of this study lies in the complementary performances of these two methods, each in its specific range, for the analysis of MTBE in water samples. Head-space gas chromatography was used as a screening technique in routine analyses, while purge-and-trap gas chromatography was used as a confirmation method for the negative results. The analytical precision was good with both methods. Detection limits were 50 μg 1−1 for head-space gas chromatography and 2 μg 1−1 for purge-and-trap gas chromatography, with 90% calculated recovery. Choice of different parameters for the purge-and-trap method is discussed.