Metal organic framework derived nitrogen doped carbon nanotube cages as efficient adsorbents for solid phase microextraction of polychlorinated biphenyls.
An efficient and stable adsorbent is of critical importance for solid phase microextraction (SPME) In this study, we prepared metal organic framework derived nitrogen (N) doped carbon (C) nanotube cages (N CNTCs) with unique N doped active sites and C rich nanotubes to coat SPME adsorbents. This new material was obtained via a simple thermal treatment with ZIF 67, and exhibited high porosity and excellent chemical and thermal stability. Compared with commercial fibers and traditional C nanotubes coated fiber (15 nm) N CNTC coated fiber exhibited better extraction properties, mainly due to its p p interactions, abundant active sites, and hollow cage structure, which is composed of interconnected crystalline N doped C nanotubes. N CNTC coated fiber exhibited better extraction performance and shorter extraction equilibrium time than the solid N doped C coated fiber due to its hollow cage structure. The N CNTC coated fiber was then used to identify polychlorinated biphenyls (PCBs) with wide linear range (0.3 1000.0 ng L 1) low limits of detection (0.10 0.22 ng L 1) good repeatability (intra day, 2.6 3.8% inter day, 3.3 4.8% and good reproducibility <8.6% We then successfully applied the N CNTC coated fiber to detect PCBs in river water samples from six cities in Fujian Province and obtained satisfactory recovery levels. Thus, the novel N CNTCs coating proposed in this study is a promising candidate for SPME coating.
Analytica chimica acta