Quantitative determination of chloramphenicol in milk powders by isotope dilution liquid chromatography coupled to tandem mass spectrometry.

摘要: Abstract A method is described for the determination of residues illegal antibiotic chloramphenicol (CAP) in milk powders. The analyte quantified by liquid chromatography coupled to electrospray ionisation tandem mass spectrometry (LC–ESI-MS–MS) operating negative ion multiple reaction monitoring mode (MRM) after a liquid–liquid extraction followed clean-up step on solid phase (SPE) cartridge. Because presence two chlorine atoms CAP molecule, four specific transition reactions were monitored MS–MS selecting m/z 321 → 257, 152 (35Cl2) and 323 (37Cl35Cl). Two calibration curves constructed plotting area ratio versus 326 157 257 262 against their corresponding amount ratio. Indeed, even if was found give higher response (calibration curve used default), an interfering chemical substance sometimes observed some extracts not 257. quantitation validated according European Union (EU) criteria analysis veterinary drug at 0.1, 0.2 0.5 μg/kg concentration levels using d5-CAP as internal standard. decision limit (CCα) detection capability (CCβ) calculated 0.02 μg/kg 0.03 μg/kg, respectively, 0.04 μg/kg, respectively. At lowest fortification level (i.e. 0.1 μg/kg), repeatability within-laboratory reproducibility both 0.03 0.05 μg/kg, Moreover, measurement uncertainty analytical same spiking falls within precision values reproducibility. This can be applied several types powders (e.g. full cream, skim) serve tool avoid that unacceptable enter food chain.