In situ self-transformation metal into metal-organic framework membrane for solid-phase microextraction of polycyclic aromatic hydrocarbons

In this work, a metal-organic framework (MOF) membrane coated copper wire (CW) was prepared as solid-phase microextraction (SPME) materials for extraction of polycyclic aromatic hydrocarbons (PAHs) from water samples. The MOF based SPME fiber was fabricated by a facile and environment-friendly strategy, where the CW acted as both substrate and the copper ion source for MOF membrane growth. Characterization results confirmed that a uniform and dense HKUST-1 membrane was grown on the smooth surface of pristine CW. The effect of extraction parameters (i.e. extraction temperature, extraction time, desorption temperature, desorption time, and salt concentration) were fully optimized. Due to its large surface areas, the MOF membrane coated CW fiber showed good performance with great repeatability (2.6-14%, n = 5), low limits of detection (LODs, 0.12-9.9 ng L-1) and wide linear range (0.01-10 mu g L-1). Moreover, the proposed method was proven to be highly effective for the determination of trace PAHs levels in real environmental water samples where the recoveries of PAHs were in the range of 80.8-114.1%, demonstrating that the as-prepared HKUST-1 membrane coated CW had great potential application in environmental water analysis.