Exploration of a coordination polymer as a novel sorbent for the solid-phase extraction of benzo[a]pyrene in edible oils

Abstract

In this paper, a zinc(II) coordination polymer, [Zn(BTA)₂]_n (BTAH = benzotriazole) was prepared, characterized and explored as a novel sorbent for the solid-phase extraction of trace benzo[a]pyrene in edible oils, with analysis using gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS, SIM). The resulting material was characterized by XRD, SEM, nitrogen adsorption analysis and elemental analysis. The adsorbent shows great adsorption affinity towards aromatics due to the strong π–π interaction and hydrophobic effect. Herein, benzo[a]pyrene (BaP) in edible oil was chosen as a probe to validate the adsorption capacity and selectivity of the material. With extraction of 0.5 g sample oil, three spiked levels at 0.5–8 μg kg⁻¹ were added, with recoveries in the range of 88.7–106% and relative standard deviations ranging from 2.9 to 9.4%. The detection limit is 0.075 μg kg⁻¹. The proposed method has been successfully applied for the trace analysis of BaP in several kinds of edible vegetable oil.