Metal organic framework derived composite as a new sorbent for micro-solid phase extraction of parabens from breast milk samples.

In an attempt to enhance the adsorptive properties while addressing the limitations associated with powdered nature, zeolitic imidazolate framework (ZIF-67)-derived cobalt-doped nanoporous carbon (Co-NPC) was incorporated into chitosan and then shaped like hollow fiber by a simple casting method. Further modification with polyaniline (PANI) was also performed to improve extraction efficacy. The applicability of the modified hollow fibers was then investigated by packing them into a cartridge and utilizing them for conducting hollow fibers-packed in-cartridge micro solid-phase extraction (HF-IC µ-SPE) of parabens including methylparaben (MP), ethylparaben (EP), and propylparaben (PP) from human breast milk samples. Factors affecting extraction performance were studied using central composite design (CCD). Under the optimal conditions, good linearity was achieved within the range of 0.5-500 μg L^-1 with the determination coefficient (R²) higher than 0.9901. All analytical parameters were obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. In this regard, the limits of detection values (LODs) were 0.5 to 1.0 μg L^-1. Intra- and inter-assay precision RSDs % were lower than 7.9 % and 8.4 %, respectively. Relative recoveries of breast milk samples were found in the range of 88.0-109.5 %. Accordingly, the novel nanocomposite sorbent based on PANI@Co-NPC/Chitosan hollow fiber was found to be an efficient, simple, and cost-effective packing material for HF-IC µ-SPE. It can also be offered as a promising alternative adsorbent to coated conventional hollow fiber.