Efficient trap of polar aromatic amines in environmental waters by electroenhanced solid phase microextraction based on porous monolith doped with carboxylic carbon nanotubes

Abstract

• A new adsorbent based on porous monolith doped with carboxylic carbon nanotubes. • Exertion of electric field during extraction period assisted the capture of polar AAs. • Extraction conditions were optimized and capture mechanism was deducted. • Practical applicability of suggested M@CCNs/EE-SPME-HPLC/DAD method was demonstrated. Efficient trap of polar aromatic amines (AAs) is challenging due to their high water-solubility. In this study, electroenhanced solid phase microextraction (EE-SPME) based on porous monolith doped with carboxylic carbon nanotubes (M@CCNs) was developed for the first time to efficiently capture AAs at trace levels in water samples. According to the chemical features of studied AAs, poly (1-vinyl-3-octylimidazolium tetrafluoroborate- co -divinylbenzene) monolith mingled with M@CCNs was fabricated on the surface of stainless steel wire and utilized as the extraction medium of EE-SPME. Results well evidenced that the introduction of carboxylic carbon nanotubes not only enhanced the surface area of monolith, but also introduced carboxyl group into the adsorbent. The implement of electric field during extraction process improved the trap performance, the extraction efficiencies increased by 36–48% compared with without application of electric field. The practicability and reliability of M@CCNs/EE-SPME was demonstrated by combining high-performance liquid chromatography with diode-array detector to quantify studied AAs in various water samples. The limits of detection and limits of quantification located at the ranges of 0.0013–0.012 μg/L and 0.0042–0.040 μg/L, respectively. The recoveries with different fortified concentrations were in the range of 83.1–118%. In addition, related extraction mechanism of M@CCNs/EE-SPME towards studied AAs was deduced.