Abstract:

An ultra high liquid chromatography-Q Exactive orbitrap mass spectrometry multi-residue method has been developed for the determination of six anticoccidials residues (dinitlmide, nicarbazin, diclazuril, toltrazuril, monensin and salinomycin) in chicken tissue. Sample preparation was based on QuEChERS method, using 1% (v/v) trichloroacetic acid/acetonitrile aqueous solution (3 : 7, v/v) as the extraction solvent and salting-out with sodium chloride followed by clean-up with 50 mg/mL primary secondary amine (PSA)+50 mg/mL neutral alumina (Alumina-N) dispersive solid phase extraction (DSPE). The separation of the compounds in liquid chromatography was carried out using a Waters Acquity UPLC^® BEH C8 column (100 mm×2.1 mm, 1.7 μ m) with mobile phases consisting of methanol-5 mmol/L ammonium acetate aqueous solution in gradient elution. The Q Exactive orbitrap mass spectrometric detection was carried out with positive and negative electrospray ionization simultaneously. The results showed the linear ranges of the six target compounds were as follows: dinitolmide, 1.0-30.0 μ g/L; nicarbazin, 0.2-6.0 μ g/L; diclazuril and toltrazuril, 2.0-60.0 μ g/L; monensin and salinomycin, 4.0-120.0 μ g/L. The external standard method was used for quantification. The spiked recoveries at three levels for the six anticoccidials ranged from 67.7% to 126.8%. The relative standard deviations (RSDs) were ≤10.4%. The limits of quantification (LOQs) were as follows: dinitolmide, 2.50 μ g/kg; nicarbazin, 0.50 μ g/kg; diclazuril and toltrazuril, 5.00 μ g/kg; monensin and salinomycin, 20.00 μ g/kg. The developed method is easy of operation and of high sensitivity. It can meet the requirements of daily inspection.

Key words: anticoccidials, chicken, QuEChERS, ultra high liquid chromatography-high resolution mass spectrometry