Simultaneous determination of chloramphenicol and florfenicol in liquid milk, milk powder and bovine muscle by LC–MS/MS

Abstract

A validated method based on European and Brazilian legislation is reported. It is applicable to the simultaneous determination of chloramphenicol (CAP) and florfenicol (FF) by LC-MS/MS in liquid milk, milk powder and bovine muscle. The chromatographic analysis is completed in 6 min and the extraction procedure is very simple, involving only one step liquid-extraction with ethyl acetate. Where it proved necessary to include clean-up, an efficient and rapid step using C18-dispersive solid was added. Initially, a complete validation was performed with liquid milk matrix; later the scope was extended to the other matrices through extending the inter-day precision (within laboratory reproducibility) RSD values. An internal standard (d₅-CAP) was employed for quantitative purposes. The method was shown to have good accuracy and precision for determining CAP residues at the level of 0.3–0.6 µg kg⁻¹ and FF residues at the level of 5–15 µg kg⁻¹.

Keywords:

• LC-MS/MS
• veterinary drugs
• residues
• validation
• chloramphenicol
• florfenicol
• MSPD

Acknowledgements

The authors are grateful to CNPq for providing scholarship.