HPLC-MS/MS Determination of Residual Amount of Nicarbazin in Animal Tissue

It was reported that residual amount of nicarbazin in animal tissue was determined by HPLC-MS/MS.Samples were extracted with a mixed solution of N,N-dimethylformamide and acetonitrile (10+90),and defatted with saturated n-hexane.After centrifugation,an aliquot of the lower layer solution was taken for separation by passing through Waters Sunfire C18 column (150 mm×2.1 mm,3.5 μm),and the content of labelled compound 4,4′-dinitro-carbanilide (DNC) for residual nicarbazin was determined by MS/MS with isotopic internal standard.Linear relationship between values of peak area and mass concentration of DNC was kept in the range of 0.010-0.200 mg·L-1,with values of detection limit (3S/N) of 30 ng·g-1 and lower limit of determination (10S/N) of 50 ng·g-1.Tests for recovery were made by addition of standard DNC at 3 different concentration levels to 3 kinds of animal tissues as matrixes,values of recovery found were in the range of 72.2%-88.6%,with values of RSD′s (n=6) in the range from 1.63% to 12.1%.