关键词: 牛乳；喹氧灵；气相色谱-质谱测定

Abstract: A gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of quinoxyfen in milk. The sample was extracted with acetronitrile, and then the extract was cleaned up by dispersive solid-phase extraction (dSPE) with C18 and N-propyl ethylenediamine (PSA) as sorbent materials. The analyte was separate on an Agilent HP- 5MS column, detected by GC-MS, and quantified by matrix-matched external standard method. The results showed that good linearity was obtained within the concentration range of 0.00–1.00 μg/mL with a correlation coefficients (R2) > 0.998 7. The average recoveries at three spiked levels (5, 10 and 20 μg/kg) ranged from 83.2% to 100.8% with relative standard deviations (RSDs) of 2.1%–4.3%. The limit of quantitation was 5 μg/kg. The proposed method was simple, sensitive and reliable, and could be applied to the determination of quinoxyfen in milk. The content of quinoxyfen in milk samples from 75 dairy households was detected to be less than the national limit value by this method.

Key words: milk; quinoxyfen; gas chromatography-mass spectrometric determination