Rapid Screening and Determination of 35 Environmental Hormones in Animal-Derived Foods by QuEChERS Combined with Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry

The 5.00 g of uniformly ground sample was taken, and 10 mL of acetonitrile solution containing 1%（volume fraction） acetic acid was added. The mixture was shaken vigorously for 5 min, followed by ultrasonication for 10 min. Then 5 g of sodium sulfate and 1 g of sodium chloride were added, and the mixture was shaken vigorously for 1 min, and placed in a freezer for 30 min at −18 ℃. After centrifuging at freezing temperature of −4 ℃ for 5 min, an aliquot （1 mL） of the supernatant was taken, and 150 mg of anhydrous magnesium sulfate, 100 mg of N-propyl ethylenediamine （PSA） powder, and 100 mg of C₁₈ powder were added. The mixed solution was shaken for 1 min by vortex, and centrifuged for 3 min. The supernatant was passed through a 0.22 μm filter membrane, and the filtrate obtained was then analyzed by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry. The 35 environmental hormones were separated by gradient elution using the acetonitrile-water system on Phenomenex Knietex^® F5 column, ionized in positive/negative ion switching mode by electrospray ionization source, and scanned in Full MS-ddMS² mode. Quantification was performed using the matrix matched method. It was shown that linear relationships between the mass fractions and peak areas of the 35 environmental hormones were kept in definite ranges, with screening limits in the range of 1.0−10 μg·kg⁻¹. Test for recovery was conducted by the standard addition method, giving recoveries in the range of 61.2%−118%, and RSDs （n=6） of the determined values ranged from 0.10% to 8.6%. The proposed method was applied to the analysis of 10 pork samples, 10 chicken samples, 10 beef samples, 10 lamb samples, 15 fish samples, 5 shrimp samples, and 5 milk samples, and prometryn was screened only in 2 fish samples, with detection amounts of 1.5, 3.6 μg·kg⁻¹, respectively.