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

<p> A sensitive and reliable method has been developed and validated to determine residues of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in bovine milk. Isolation of the analytes from milk was performed with the use of liquidliquid extraction with acetonitrile in the presence of sodium chloride. The extract was defatted with hexane and cleaned up using solid phase extraction (C8 cartridge) after forming ion pairs with triethylamine. The analytes were derivatized with N, Ndimethylformamide, acetic acid anhydride, and N-methylimidazole (100°C, 90 min). The derivatives were determined by reverse phase liquid chromatography with fluorescence detection (excitation and emission wavelength 365 nm and 475 nm, respectively). Recoveries of the lactones from milk samples fortified at 10-30 μg kg<sup>-1</sup> ranged from 52% to 80% with intra-laboratory reproducibility (CV) of 12.7%-22.8%. The critical concentrations (decision limit, CCα and detection capability, CCβ) were in accordance with target limits. The method has been verified in the proficiency studies by EURL/CVL Berlin (all z-scores in the range of ±2). The method was transferred to routine laboratories, verified in inter-laboratory comparison and successfully applied in the National Residue Control Plan.</p>
</abstract>

A sensitive and reliable method has been developed and validated to determine residues of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in bovine milk. Isolation of the analytes from milk was performed with the use of liquidliquid extraction with acetonitrile in the presence of sodium chloride. The extract was defatted with hexane and cleaned up using solid phase extraction (C8 cartridge) after forming ion pairs with triethylamine. The analytes were derivatized with N, Ndimethylformamide, acetic acid anhydride, and N-methylimidazole (100°C, 90 min). The derivatives were determined by reverse phase liquid chromatography with fluorescence detection (excitation and emission wavelength 365 nm and 475 nm, respectively). Recoveries of the lactones from milk samples fortified at 10-30 μg kg-1 ranged from 52% to 80% with intra-laboratory reproducibility (CV) of 12.7%-22.8%. The critical concentrations (decision limit, CCα and detection capability, CCβ) were in accordance with target limits. The method has been verified in the proficiency studies by EURL/CVL Berlin (all z-scores in the range of ±2). The method was transferred to routine laboratories, verified in inter-laboratory comparison and successfully applied in the National Residue Control Plan.

Control of Residues of Five Macrocyclic Lactones in Cow Milk By Liquid Chromatography with Fluorescence Detection

Department of Pharmacology and Toxicology

Journal of Veterinary Research

A sensitive and reliable method has been developed and validated to determine residues of abamectin, doramectin, eprinomectin, ivermectin, and moxidectin in...

Control of Residues of Five Macrocyclic Lactones in Cow Milk By Liquid Chromatography with Fluorescence Detection

Published Online: Jan 17, 2013

Page range: 595 - 599

DOI: https://doi.org/10.2478/v10213-012-0105-2

Keywords
macrocyclic lactones, cow milk, residues, liquid chromatography, fluorescence detection

This content is open access.

Control of Residues of Five Macrocyclic Lactones in Cow Milk By Liquid Chromatography with Fluorescence Detection

Published Online: Jan 17, 2013

Page range: 595 - 599

DOI: https://doi.org/10.2478/v10213-012-0105-2

Keywordsmacrocyclic lactones, cow milk, residues, liquid chromatography, fluorescence detection

This content is open access.

Keywords
macrocyclic lactones, cow milk, residues, liquid chromatography, fluorescence detection