Headspace solid-phase microextraction using poly(ethylene glycol) grafted multi-walled carbon nanotube fibers for the determination of methyl tert-butyl ether in water samples

Abstract

A simple, sensitive, and accurate method for the determination of methyl tert-butyl ether (MTBE) in water samples has been developed based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-flame ionization detection (GC-FID). A sol–gel based coating fiber using poly(ethylene glycol) (PEG) grafted onto multi-walled carbon nanotubes (PEG-g-MWCNTs) as the extraction phase was prepared and used for the extraction of MTBE. The relative standard deviations (RSDs) for one fiber (repeatability) (n = 6) and between fibers or batch to batch (reproducibility) (n = 3) were obtained. The repeatability was assessed at low (0.1 ng mL⁻¹) and high (100 ng mL⁻¹) concentrations and the RSDs obtained were 5.3 and 4.1%, respectively. The reproducibility obtained for a concentration of 0.1 ng mL⁻¹ was 6.5%. The calibration curve of MTBE was linear in the range from 0.07 to 500 ng mL⁻¹. The limits of detection (S/N = 3) of 0.01 ng mL⁻¹ and the limits of quantification (S/N = 10) of 0.07 ng mL⁻¹ were obtained. The developed method was applied successfully to determine trace level of MTBE in real water samples. The relative recoveries for the spiked samples with 5 ng mL⁻¹ of MTBE were ranged from 91 to 112% and the relative standard deviations were less than 7.8%.