Determination and Uncertainty Evaluation of Vancomycin Residues in Meat by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of vancomycin residues in meat samples. Sample were extracted with a mixed solution of formic acid and acetonitrile, degreased with n-hexane and purified by solid-phase extraction on C₁₈ cartridges. The target compound was detected by electrospray ionization (ESI) in positive ion mode with multiple reaction monitoring (MRM) and quantified by an external standard method. The results showed a good linear relationship was found between the peak area of quantitative ions and the concentration of vancomycin with a correlation coefficient of 0.9997, and the limit of detection (LOD) of this method was 0.1 μg/kg. The recoveries of vancomycin at three different spiked levels ranged from 86.7% to 100.3%, with a relative standard deviation (RSD) of 2.52%. In addition, the uncertainty for the determination of vancomycin residues in meat using this method was evaluated. It was found that at the 95% confidence level, the residual amount of vancomycin in pork was expressed as (0.342 ± 0.041) µg/kg when the expansion factor (k) was 2. The proposed method was simple, efficient, sensitive, accurate, stable, and suitable for routine analysis.