Rapid determination of four phenolic environmental estrogen residues in cooking oil by ultra-performance liquid chromatography-high resolution mass spectrometry coupled with solid-phase extraction

: A fast, sensitive and accurate method for the determination of trace bisphenol S (BPS), bisphenol F (BPF), bisphenol A (BPA) and 4-nonylphenol (4-NP) in cooking oil samples was developed by ultra-performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) coupled with solid-phase extraction (SPE). Cooking oil samples were extracted by acetonitrile, then the supernatant was purified by SLC SPE cartridges. The chromatographic separation was carried out on a Waters ACQUITY UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm) with a linear gradient elution procedure using 0.05% (v/v) triethanolamine aqueous solution and methanol as mobile phases. The quantification analysis was operated in a negative electrospray ion (ESI-) source mode under the selected ion monitoring (SIM) mode with internal standard method. The four target analytes showed good linearity with correlation coefficients (r) greater than 0.999. The limits of detection (LODs, S/N=3) and limits of quantification (LOQs, S/N=10) were in the ranges of 0.03-0.11 μg/kg and 0.10-0.36 μg/kg, respectively. The recoveries of the four target analytes spiked in oil samples were in the range of 86.3%-96.1% at spiked levels of 1.0, 10.0 and 80.0 μg/kg, respectively, while the relative standard deviations (RSDs) were in range of 2.2%-8.8% (n=6). No significant matrix interference was found in this method. The proposed method is simple and fast. It can be applied for the rapid determination of trace BPS, BPF, BPA, and 4-NP in cooking oil samples.