Abstract:A method for the simultaneous determination of five nitrofuran metabolites in meat meal by liquid chromatography tandem mass spectrometry (LC-MS/MS) was established, based on isotope dilution and solid phase extraction (SPE). The homogenized sample was spiked with isotope inter standards, hydrolyzed with HCl, derivatized with nitrobenzaldehyde, extracted with ethyl acetate, and cleaned up with HLB solid phase extraction cartridge. The analysis was carried out on C18 column by gradient elution with acetonitrile – ammonium acetate as mobile phase, and detected by MS/MS system with switch positive and negative electrospray ionization under multiple reaction monitoring (MRM) mode. The compounds was identified with retention time and ion ratio and quantified by the internal standard calibration curve of isotope dilution technique. The results showed that the high correlation coefficients (r>0.9990) of five targets were obtained within their respective linear ranges over dynamic range of 0.2~20 μg/L and the limits of detection (LOD, S/N=3) of five analytes were in the range of 0.05~0.2 μg/kg. The average recoveries were ranged from 80.33% to 103.24% for the five targets at three spiked levels with the relative standard deviations (RSD, n=6) were between 4.60% and 9.85%, and the inter-day RSD (n=5) was less than 10.3% at spiked levels of 0.5 μg/kg. The method was precise and sensitivity, suitable for quantitative and qualitative analysis of five nitrofuran metabolites in meat meal.
