液相色谱-串联质谱法检测猪粪便中除虫脲的方法学研究OACSTPCD

Diflubenzuron(DFB)belongs to benzoylphenyl ureas compounds,which inhibit the chitin synthesis and development of insect and their larvae.In order to investigate the concentration of DFB in swine feces after administration of diflubenzuron premix through mixed feeding,a method of liquid chromatography-tandem mass spectrometry(LC-MS/MS)with DFB-13 C6 as the internal standard(IS)was de-veloped to determine DFB in the feces.The DFB in swine feces samples was extracted by glacial acetic acid-acetonitrile,and the extracted solution was cleaned up by QuEChERS technology.The DFB was determined by LC-MS/MS and quantified using the internal standard meth-od.The results showed that the matrix of swine feces had little interference with the quantitative detection of DFB,and the method had high sensitivity with a limit of detection of 10 ng/g and a limit of quantitation(LOQ)of 20 ng/g.The matrix effect of the method had little influ-ence on the detection of the samples.The linearity was good(R2≥0.99)when the standard solutions were in the concentration range of 2 ng/mL to 500 ng/mL.The average accuracy of the method was between 93% and 110% and the intra-assay and inter-assay precisions were both less than 10% when the spiked concentrations were at LOQ 20 ng/g,and at low(100 ng/g),medium(1000 ng/g)and high(5000 ng/g)added concentrations.These results met the methodological requirements.The processed solution at different spiked concentrations had good stability when placed at room temperature for 24 h.However,repeated freeze-thaw of the sample should be avoided.The proposed method might be employed to determine DFB concentration in swine feces,which would provide a reliable method for future clinical trials of diflubenzuron premix.