Abstract: A method was established for the determination of nosiheptide in egg samples using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Egg samples were extracted with acidic acetonitrile, defatted with n-hexane and then purified by solid phase extraction (SPE) on an HLB cartridge. The extract was analyzed by HPLC-MS/MS in the negative electrospray ionization mode using multiple reaction monitoring (MRM). The sample pretreatment?and the experimental conditions were optimized. Fast analysis was achieved when the sample was extracted with 1% formic acid-acetonitrile, cleaned up on an Oasis HLB cartridge, and filtered with a porous polytetrafluoroethylene (PTFE) membrane and ammonium acetate-acetonitrile was used as the mobile phase. A matrix-matched standard calibration curve was prepared and external standard method was used for quantification under the optimal conditions. Good linearity was observed in the concentration range from 1.0 to 20.0 μg/L with a correlation coefficient over 0.998. The limit of detection was 0.3 μg/kg, and the limit of quantification was 1.0 μg/kg. The average recoveries at spiked levels of 1.0, 2.0 and 10 μg/kg were in the range from 83.8% to 96.2%, with relative standard deviations (RSDs) between 6.0% and 8.8%. In conclusion, the developed method is simple, fast, sensitive, accurate, and can be applicable for the detection of nosiheptide in egg samples.

Key words: nosiheptide; solid phase extraction; high performance liquid chromatography-tandem mass spectrometry; egg