Trace analysis of methyl tert-butyl ether in water samples using headspace solvent microextraction and gas chromatography-flame ionization detection.

In this study, a simple, rapid and efficient method for the extraction and determination of MTBE in water samples by the headspace solvent microextraction (HSME) and gas chromatography at sub (microg/l) level is described. Some significant variables such as type of solvent, extraction time, salt concentration, sample and microdrop volumes, stirring rate, sample and microsyringe needle temperatures were optimized. Using optimum extraction conditions (benzyl alcohol as extracting solvent, 4 M NaCl, sample temperature 35 degrees C, sample volume 6 ml, stirring rate 1000 rpm, microsyring needle temperature -6 degrees C, extraction time 7.5 min and micro drop volume of 2 microl) a detection limit of 0.06 microg/l and a good linearity (R2 > 0.999) in a calibration range of 0.1-500 microg/l were achieved. This HSME method was applied to the analysis of MTBE in tap, well and spring waters and a groundwater sample contaminated by leaking gasoline from an underground storage tank (LUST) in a gasoline service station.