title: Optimization of dispersive liquid-liquid microextraction and improvement of detection limit of methyl tert-butyl ether in water with the aid of chemometrics.
abstract: Dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-mass spectrometry-selective ion monitoring (GC-MS-SIM) was applied to the determination of methyl tert-butyl ether (MTBE) in water samples. The effect of main parameters affecting the extraction efficiency was studied simultaneously. From selected parameters, volume of extraction solvent, volume of dispersive solvent, and salt concentration were optimized by means of experimental design. The statistical parameters of the derived model were R(2)=0.9987 and F=17.83. The optimal conditions were 42.0 μL for extraction solvent, 0.30 mL for disperser solvent and 5% (w/v) for sodium chloride. The calibration linear range was 0.001-370 μg L(-1). The improved detection limit with the aid of chemometrics was 0.3 ng L(-1). The relative standard deviation (RSD) with n=9 for 0.1 mg L(-1) MTBE in water with and without internal standard was 2.7% and 3.1%, respectively. Under the optimal conditions, the relative recoveries of spiked MTBE in different water samples were in the range of 100-105%.
authors.affiliation: School of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-64555, Tehran, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Karimi
authors.forename: Hassan
authors.initials: H
authors.lastname: Sereshti
authors.forename: Soheila
authors.initials: S
authors.lastname: Samadi
authors.forename: Hadi
authors.initials: H
authors.lastname: Parastar
mesh_terms: D000704:Analysis of Variance; D005591:Chemical Fractionation / Q000379:methods*; D003205:Computing Methodologies; D003627:Data Interpretation, Statistical; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D016014:Linear Models; D008738:Methyl Ethers / Q000032:analysis*; D008956:Models, Chemical; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008738:Methyl Ethers; D014874:Water Pollutants, Chemical; C043243:methyl tert-butyl ether