Use of Ionic Liquids for Trace Analysis of Methyl Tert-Butyl Ether in Water Samples using in situ Solvent Formation Microextraction Technique and Determination by GC/FID

Abstract

A simple and efficient method for the determination of methyl tert-butyl ether (MTBE) in water samples is presented. The analytical method is based on use of 1-octyl-3-Methyl-imidazolium chloride [OMIM][Cl] and sodium hexafluorophosphate (NaPF6) as an extractant solvent ([OMIM][PF6] is established and finally MTBE separated/preconcentrated by an in situ solvent formation microextraction (ISFME) technique. Later on, the extractant containing the analyte is recovered by centrifugation and thermally desorbed. The analyte is finally determined by gas chromatography/flame ionization detection (ISFME-GC/FID). The main variables involved in the extraction and thermal desorption steps have been studied in depth. Once evaluated, the analytical method has been characterized in terms of linearity, sensitivity, precision, and accuracy. The limit of detection was 0.09 μg L−1 while the precision, expressed as relative standard deviation, was 1.9% (n = 7). In addition, acceptable recovery values were obtained in samples of different sample including lake, rain, tap, and well water samples.