Spin-column micro-solid phase extraction of phthalate esters using electrospun polyacrylonitrile/iron (III)/Mg-based metal-organic framework 88B followed by GC analysis

An electrospun composite polyacrylonitrile/iron (III)/Mg-based metal-organic framework 88B (PAN/Fe/Mg-MIL-88B) was prepared, and then utilized as a viable sorbent for the simultaneous determination of five phthalate esters in store-bought bottled mineral water and orange juice, urine, plasma, and two different types of cream and lipstick applying spin column micro solid-phase extraction (SC-mu SPE) method. The synthesis of the electrospun nanofibers was surveyed using energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and Fourier transform infrared spectroscopy, while the morphology of the composite was investigated using field emission scanning electron microscopy. The presence of Fe/Mg-MIL-88B with high quantity of functional groups and porous structure in the polymer matrix endows the PAN nanofibers with high extraction efficiency. The effect of MOF% in the composite nanofibers, amount of sorbent, sample pH, type and volume of desorption solvent, salt concentration, number of cycles, and centrifugation speed were optimized. Under the optimal conditions, the calibration plots for dimethyl phthalate (DMP), diethyl phthalate (DEP), and diallyl phthalate (DAP) were linear within the range of 1.0-1000.0 ng mL(-1); and 0.5-1000.0 ng mL(-1) for diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP). The limits of detection were lower than 0.30 ng mL(-1) for DMP, DEP, and DAP and 0.15 ng mL(-1) for DIBP and DBP by GC-FID. The data related to the relative standard deviations were in the range of 4.1%-6.3% (intra-day, n = 5) and 6.4%-7.9% (inter-day, n = 3) in the span of three days. Finally, the applicability of the method was scrutinized for the quantification of analytes of interest in spiked samples, and satisfactory recoveries were attained within the range of 84.8-102.8%.