Abstract: 【Objective】 This study was constructed to establish a method for the determination of the mass concentration of dicyclanil and its metabolites 2,4,6-triamino-5-pyrimidinecarbonitrile in sheep tissue by ultra-high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).【Method】 Sheep tissues (muscle,fat,liver and kidney) were pretreated.Acetonitrile and heptafluorobutyric acid aqueous solution were used as mobile phases,Acquity UPLC Beh C18 column was used for gradient elution.The flow rate was 0.15 mL/min,the column temperature was 30 ℃ and the injection volume was 5 μL.The data were collected by multi-reaction monitoring in positive ion scanning mode,and the concentrations of dicyclanil and its metabolites were determined by external standard method.The linear range,detection limit,quantitative limit,recovery rate,intra-assay and inter-assay precision,accuracy and stability of the method were investigated.【Result】 The established detection method had high sensitivity,the detection limit was 10 μg/kg,and the limit of quantitation was 20 μg/kg.The addition concentrations of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile were in the range of 20 to 1 000 μg/kg,and the linear relationship between the standard curves was good,with correlation coefficients ≥0.99.The recoveries of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile were 70% to 110% when they were added to the blank tissues at high,medium,low and limited quantification levels,and the coefficient of variation within and between batches was less than 15%.The stability of dicyclanil and 2,4,6-triamino-5-pyrimidinecarbonitrile in different tissues was good under the conditions of investigation.【Conclusion】 The established UPLC-MS/MS assay was specific,reproducible and sensitive,and could be used for pharmacokinetic and residual studies of dicyclanil emulsion in sheep tissues.

Key words: dicyclanil; 2,4,6-triamino-5-pyrimidinecarbonitrile; UPLC-MS/MS; sheep