Development and validation of rapid multiresidue and multi-class analysis for antibiotics and anthelmintics in feed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry

摘要

A new multi-residue method for the analysis of veterinary drugs, namely amoxicillin, chlortetra-cycline, colistins A and B, doxycycline, fenbendazole, flubendazole, ivermectin, lincomycin, oxyte-tracycllne, sulfadiazine, tiamulin, tilmicosin and trimethoprim, was developed and validated for feed. After acidic extraction, the samples were centrifuged, purified by SPE and analysed by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. Quantitative validation was done in accordance with the guidelines laid down in European Commission Decision 2002/657/CE. Matrix-matched calibration with internal standards was used to reduce matrix effects. The target level was set at the authorised carryover level (1%) and validation levels were set at 0.5%, 1% and 1.5%. Method performances were evaluated by the following parameters: linearity (0.986 ＜ R~2 ＜ 0.999), precision (repeatability ＜ 12.4% and reproducibility ＜ 14.0%), accuracy (89% ＜ recovery ＜ 107%), sensitivity, decision limit (CCct), detection capability (CCβ), selectivity and expanded measurement uncertainty (k = 2).This method has been used successfully for three years for routine monitoring of antibiotic residues in feeds during which period 20% of samples were found to exceed the 1% authorised carryover limit and were deemed non-compliant.