Functionalized carbon nanotube/ionic liquid-coated wire as a new fiber assembly for determination of methamphetamine and ephedrine by gas chromatography-mass spectrometry

Analytical Methods Pub Date: 2014-09-24 DOI: 10.1039/C4AY01394H

Abstract

A new ionic liquid (IL), 1-methyl 3-[(3-octylamino)propyl] imidazolium bis(trifluoromethane sulphonyl)imide [OAPMIM][NTf2], was synthesized and characterized by 1H-NMR. The multi-walled carbon nanotubes were functionalized with diethyl amine (FMWCNT) and dispersed in this ionic liquid. Then gel-like solution, once formed, was immobilized on a stainless steel wire to act as a novel solid phase microextraction fiber. This fiber was applied for the purpose of extraction/preconcentration of methamphetamine (MAP) and ephedrine (EP) prior to determination by gas chromatography-mass spectrometry. The efficiency of fiber coating in the extraction of methamphetamine and ephedrine was compared with that of 1-octyl-3-methylimidazolium bis(trifluoromethanesulphonyl) imide [OMIM][NTf2] and N-octylpyrdinuim hexaflourophosphate [OPY][PF6] and, non-functionalized multi-wall carbon nanotubes have/had different polarities and physical properties. The highest efficiency and most desirable results were achieved using [OAPMIM][NTf2]-FMWCNT as fiber coating. The calibration curves were linear in the ranges of 1 to 150 and 0.5 to 250 μg L?1 for MAP and EP, respectively. The limits of detection (LODs) were obtained as 0.1 and 0.07 μg L?1 for MAP and EP, respectively. The developed method was successfully applied to the determination of MAP and EP in urine samples, and the recoveries were found to be 99.0(±5.0)% at the spiking level of 0.1 μg mL?1.

Graphical abstract: Functionalized carbon nanotube/ionic liquid-coated wire as a new fiber assembly for determination of methamphetamine and ephedrine by gas chromatography-mass spectrometry
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