Determination of chloramphenicol in animal urine by liquid chromatography-tandem mass spectrometry

The method was developed for the determination of chloramphenicol (CAP) in animal urine using LC-ESI-MS-MS. The sample was diluted with water, loaded onto a Chem Elut cartridge, and eluted with ethyl acetate. LC separation was achieved by using a Phenomenex Luna C-18 column. The mass spectrometer was operated in multiple reaction monitoring mode (MRM) with negative electrospray interface (ESI-). The four transitions were monitored m/z 321 -> 257, 321 -> 194, 321 -> 152, 326 -> 157(IS) and for quantification, the transition m/z 326 -> 152 was chosen. The method validation was done according to the criteria laid down in Commission Decision No. 2002/657/EC. The validation includes the determination of specification, linearity, repeatability, within-laboratory reproducibility, accuracy, trueness, decision limit (CC(x), and detection capability (CC). Urine_samples were fortified at CAP levels 0.30, 0.45, and 0.60 lig/kg with CAP-d5 as internal standard. At these levels, repeatability (RSD %) was lower than 9%, accuracy (RE, %) ranged from -8.7% to 0.4% and mean trueness (recovers) was between 91% and 100%. RSD within-laboratory reproducibility was lower than 10%. The limit of decision (CC alpha) and detection capability (CC beta) was 0.08 and 0.10 mu g/kg.