<abstract xmlns="http://www.w3.org/1999/xhtml">

<p> A multiresidue method for the determination of seven nitroimidazoles and their hydroxy metabolites in milk was developed. Milk samples were extracted with acetonitrile and cleaned up on strong cation-exchange solid phase extraction cartridges. Evaporated to dryness first, the extracts obtained were then reconstituted in 0.1% formic acid and injected onto a liquid chromatography-tandem mass spectrometer (LC-MS/MS). The separation of analytes was achieved on gradient mode using a C18 column and a mobile phase consisting of 0.1% formic acid in acetonitrile and 0.1% formic acid in water. Multiple reaction monitoring mode was set for the MS/MS with positive electrospray ionisation. For quantification, the isotope dilution method was used with isotopically labeled analogues of the target analytes. The method was evaluated entirely in accordance with EU Commission Decision 2002/657/EC and all validation criteria were in the required ranges. The method can easily detect and confirm metronidazole, dimetridazole, ronidazole, ipronidazole, and their hydroxy metabolites below the recommended concentration level of 3 μg/kg. The decision limits and detection capabilities ranged from 0.11 μg/kg to 0.22 μg/kg and from 0.19 μg/kg to 0.37 μg/kg respectively. The overall recoveries were between 96.6% and 105.2% with a good coefficient of variation, less than 8.7% under within-laboratory reproducibility conditions.</p>
</abstract>

A multiresidue method for the determination of seven nitroimidazoles and their hydroxy metabolites in milk was developed. Milk samples were extracted with acetonitrile and cleaned up on strong cation-exchange solid phase extraction cartridges. Evaporated to dryness first, the extracts obtained were then reconstituted in 0.1% formic acid and injected onto a liquid chromatography-tandem mass spectrometer (LC-MS/MS). The separation of analytes was achieved on gradient mode using a C18 column and a mobile phase consisting of 0.1% formic acid in acetonitrile and 0.1% formic acid in water. Multiple reaction monitoring mode was set for the MS/MS with positive electrospray ionisation. For quantification, the isotope dilution method was used with isotopically labeled analogues of the target analytes. The method was evaluated entirely in accordance with EU Commission Decision 2002/657/EC and all validation criteria were in the required ranges. The method can easily detect and confirm metronidazole, dimetridazole, ronidazole, ipronidazole, and their hydroxy metabolites below the recommended concentration level of 3 μg/kg. The decision limits and detection capabilities ranged from 0.11 μg/kg to 0.22 μg/kg and from 0.19 μg/kg to 0.37 μg/kg respectively. The overall recoveries were between 96.6% and 105.2% with a good coefficient of variation, less than 8.7% under within-laboratory reproducibility conditions.

Confirmatory method for the determination of nitroimidazoles in milk by liquid chromatography - tandem mass spectrometry

Department of Pharmacology and Toxicology

Journal of Veterinary Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

A multiresidue method for the determination of seven nitroimidazoles and their hydroxy metabolites in milk was developed. Milk samples were extracted with...

Confirmatory method for the determination of nitroimidazoles in milk by liquid chromatography - tandem mass spectrometry

Published Online: Dec 20, 2014

Page range: 581 - 587

Received: Mar 13, 2014

Accepted: Oct 14, 2014

DOI: https://doi.org/10.2478/bvip-2014-0090

Keywords
milk, nitroimidazoles, residues, liquid chromatography, tandem mass spectrometry

© 2014 National Veterinary Research Institute in Pulawy

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Confirmatory method for the determination of nitroimidazoles in milk by liquid chromatography - tandem mass spectrometry

Published Online: Dec 20, 2014

Page range: 581 - 587

Received: Mar 13, 2014

Accepted: Oct 14, 2014

DOI: https://doi.org/10.2478/bvip-2014-0090

Keywordsmilk, nitroimidazoles, residues, liquid chromatography, tandem mass spectrometry

© 2014 National Veterinary Research Institute in Pulawy

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
milk, nitroimidazoles, residues, liquid chromatography, tandem mass spectrometry