[Determination of metabolites of nitrofuran antibiotics in royal jelly by high performance liquid chromatography-tandem mass spectrometry].

Nitrofurans are a group of widely used veterinary antibiotics that have been banned in many countries. This has generated a great deal of interests and demands for assay of nitrofurans in animal food products. To our knowledge, this is the first time that a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method has been successfully developed for simultaneously analyzing the metabolites of four nitrofuran antibiotics (furazolidone, furaltadone, nitrofurazone and nitrofurantoin) in royal jelly. Trichloroacetic acid solution was used both to precipitate proteins and to provide acidic reaction condition. Four isotope internal standards were utilized to improve the quantitative precision. The limits of detection (LODs) were 0.03 microg/kg for the metabolite of furaltadone and 0.05 microg/kg for the other three metabolites. The limits of quantitation were 0.20 microg/kg for the metabolite of furaltadone and 0.25 microg/kg for the other three metabolites. The linear range was 0.4-20 ng/mL for all the target analytes. The recoveries calibrated by internal standard were in the range of 97.7%-104.8 with the relative standard deviations (RSDs) of 2.7-9.7. It showed that this method could meet the requirements of national monitoring plan in China and the Minimum Required Performance Limits (MRPL) set by the European Union.