Abstract: A method of liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of linuron and its metabolite 3,4-dichloroaniline residues in pork, liver, kidney, casings, canned steam pork and sausage. The sample was extracted with a mixture of acetone-acetonitrile (5:95, v/v). Most of the lipids in the extract were eliminated by freezing-lipid filtration. After Florisil solid phase extraction cleanup, the linuron and its metabolite residues were determined by LC-MS/MS, and quantified by internal standard method. In the range of 1~500 μg/L, both linuron and 3,4-dichloroaniline showed good linearity with the correlation coefficients (r) more than 0.998. The limit of quantification (S/N＞10) was 10 μg/kg, and the limit of detection (S/N＞3) was 5 μg/kg for each analyte. The recoveries of linuron and 3,4-dichloroaniline in meat and meat products at three spiked levels were in the ranges of 88.3%~101.2% and 91.6%~101.6%, and the relative standard deviations were in the ranges of 4.8%~13.7% and 4.7%~11.8%, respectively. The results demonstrated that the proposed method can meet the requirements for the determination of linuron and 3,4-dichloroaniline in meat and meat products.

Key words: 3,4-dichloroaniline, linuron, meat, meat products, liquid chromatography-tandem mass spectrometry(LC-MS/MS)