Metal azolate framework-66-coated fiber for headspace solid-phase microextraction of polycyclic aromatic hydrocarbons.

Metal azolate frameworks (MAFs) as a subfamily of metal-organic frameworks (MOFs) have received much attention in analyzing organic volatiles owing to their remarkable structures. In this work, the headspace solid-phase microextraction (SPME) fiber based on MAF-66 has been fabricated by a layer-by-layer deposition method. To evaluate the performance of the MAF-66-coated fibers, polycyclic aromatic hydrocarbons (PAHs) were tested as analytes with gas chromatography (GC). Relevant experimental parameters were optimized including extraction temperature, extraction time, desorption temperature, desorption time, the stirring rate and salt concentration. Under optimum condition, PAHs including naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene were detected with good linear range (0.01-100 μg L-1), low detection limits (0.1-7.5 ng L-1), high enrichment factors (123-3108) and relative standard deviations (RSDs) ranging from 0.23% to 4.2%. Additionally, the fiber exhibited a long lifetime with repetitively used more than 270 times. The proposed method was also successfully applied for the determination of PAHs in environmental samples and food samples.