A Sensitive Method for Methyl tert-Butyl Ether Analysis in Water Samples by a New HS-SPME Vial and GC

Abstract

In this study, a new sample vial has been designed for the extraction and determination of methyl tert-butyl ether (MTBE) in water samples by headspace solid-phase microextraction method. The special feature of this new vial is cooling the HS above the aqueous sample by cold water stream for maximum analyte absorption on SPME fiber coating. The analysis was by a gas chromatograph equipped with flame ionization detector and a capillary column (CP-sil 13 CB). Some significant variables affecting the extraction procedure were optimized. By use of divinylbenzene/carboxen/polydimethylsiloxane fiber, a sample volume of 10 mL, stirring rate of 1,000 rpm, salt concentration of 24%, extraction time of 15 min and extraction temperature of 83 °C, detection limit of 0.022 μg L−1 and a good linearity (R2 = 0.998) in a calibration range of 0.1–400 μg L−1 were achieved. The relative standard deviation for triplicate runs ranged between 6 and 8%. The method could be applied to the analysis of trace levels of MTBE in various water samples.