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 (NaPF 6 ) as an extractant solvent ([OMIM][PF 6 ] 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.

2-Hydroxyethylammonium Bisulfate (2-HEAS) as a Brønsted Acidic Ionic Liquid Catalyst for Esterification

“…Ionic liquids (ILs) are known as an environmentally safe alternative to acidic catalysts, mainly due to their low vapor pressure, good thermal stability, high decomposition temperature, environmental compatibility, and ability to dissolve a wide range of organic molecules. 2,24 These findings have already been reported by several researchers on the use of ionic liquids as catalysts instead of harmful catalysts. Liu et al ) was synthesized, characterized, and used as catalyst for esterification of three usual alcohols (methanol, ethanol, and butanol) with acetic acid as the raw material (Scheme 1).…”

“…Of course, this substance is highly corrosive and dangerous, so its use in this process poses a threat to the environment. Ionic liquids (ILs) are known as an environmentally safe alternative to acidic catalysts, mainly due to their low vapor pressure, good thermal stability, high decomposition temperature, environmental compatibility, and ability to dissolve a wide range of organic molecules. , These findings have already been reported by several researchers on the use of ionic liquids as catalysts instead of harmful catalysts. Liu et al reported 1-(3-sulfopropyl)-1-methylpyrrolidone sulfonate ([C 3 SO 3 Hnmp]­[HSO 4 ]) with high catalytic activity, and Zhou et al reported methyl-2-pyrrolidonium hydrogen sulfate ([Hnmp]­[HSO 4 ]) as a catalyst, which gives better conversion than H 2 SO 4 .…”

“…They are liquid at a temperature of 100 °C or less. ILs have unique physical and chemical properties and are widely regarded in the materials and chemical sciences. , To evaluate the application of IL in several fields such as gas absorption and separation, as an electrolyte in solar cells, as organic transformations, as lubricating additives, as a solvent, and as a mold for the dispersion and synthesis of nanoparticles and liquid–liquid extraction, ILs have been tested depending on the nature of the constituent ions. ILs contain organic cations such as conventional aromatic rings and various aliphatic chains on ammonium ions .…”