A simple strategy based on fibers coated with surfactant-functionalized multiwalled carbon nanotubes to improve the properties of solid-phase microextraction of phenols in aqueous solution.

In this study, a functionalized multiwalled carbon nanotube (MWCNT)-coated solid-phase microextraction (SPME) fiber was developed for concentrating analytes in aqueous samples. Sodium deoxycholate (NaDC) was used as a dispersing agent for non-covalent modification of MWCNTs. The coating showed porous structure and large adsorption capacity. To investigate the capability of this MWCNTs/NaDC SPME fiber, it was applied to the analysis of phenols in aqueous solution. After extraction, the analytes were desorbed in an acetonitrile-water solution and analyzed using high-performance liquid chromatography. The MWCNTs/NaDC fiber exhibited good analytical performance, and fine preparation reproducibility was obtained with the relative standard deviations (RSDs) ranging from 4.9% to 10.2% (n = 6) in one batch, from 5.7% to 11.9% (n = 3) among different batches. Under the optimum extraction conditions, the detection limits were 0.15-0.30 ng/mL(S/N = 3), the linear detection ranges were 1-100 ng/mL (R2 ≥ 0.9997) for these analytes, and good recoveries (80.3-95.4%) were obtained for the spiked samples. This is a simple and accurate pretreatment method for the analysis of phenols in aqueous samples.