The geometrical characteristics of nickel-based metal organic framework on its entrapment capability

Here, a three dimensional nickel-based metal organic framework (MOF) was synthesized via solvothermal and room temperature protocols. In order to study the effects of the synthesis conditions on the physical properties such as pore sizes and shapes of the prepared MOFs, their extraction capabilities were examined. Both MOFs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller and thermogravimetric analyses. Brilliant properties such as porous structure, high surface area and considerable thermal stability make them reasonable candidates to be employed as efficient extractive phases. The efficiency of the superior nickel-based MOF was evaluated for headspace needle trap extraction of chlorobenzenes as model compounds in conjunction with gas chromatography-mass spectrometry (GC-MS). The MOF-based extractive phase was conveniently packed in a needle trap device and after extraction, the desorption process was performed via direct insertion of needle into the GC inlet. After optimizing the extraction/desorption conditions, the figures of merit such as linear dynamic range was in the range of 5-1000 ng L^-1 (R² > 0.987) while the limits of detection and quantification values were 2-10 and 6-30 ng L^-1, respectively. The intra- and inter-day relative standard deviations for three replicates at the concentration level of 50 ng L^-1 were in the range of 7-9% and 9-12%, respectively. The needle-to-needle reproducibility was also found to be in the range of 5-11%. Acceptable relative recovery values at the concentration level of 50 ng L^-1 ranged from 85 to 96%, showing no significant matrix effect.