Determination of methyl tert-butyl ether (MTBE) in aqueous samples by purge and trap-gas chromatography-flame ionization detector

A purge-and-trap method was developed for sensitive and fast determination of trace MTBE in aqueous samples. The sample solutions were added with 10% (w/w) sodium sulfate and adjusted to pH 4 by acetic acid and sodium acetate buffer solution to improve the purge efficiency before the analysis. A CP-4010 purge-and-trap injector (PTI) was used to purge MTBE from water and cool it in the cold-trap kept at -75degreesC, then the cooled trap was flash heated to release the analytes onto a HP-1 capillary column and detected by gas chromatography-flame ionization detector (GC-FID). A good linear response was obtained and the detection limit was 0.1 mug L -1 . This method has been successfully applied to the determination of MTBE in several Chinese river samples.