The development, validation and application of mass spectrometric methods for veterinary drug residue analyses in food.

Abstract

Restricting the use of veterinary medicines, or the inappropriate, excessive, incorrect or fraudulent use of medicines requires effective monitoring programmes for veterinary drug residues in food. The scope of this thesis was to develop and validate sensitive quantitative multi-residue confirmatory methods (LC-MS/MS based) for the analysis of authorised, unauthorised or prohibited antibiotics in tissue or milk matrices, and quantitative confirmatory methods for analysis of total florfenicol (FF) related residue content in tissue or milk samples. To confirm fitness for purpose all the methods presented have been validated for use in accordance with internationally recognised (EU) performance criteria and verified in external proficiency tests.The methods presented for analysis of total FF content fulfil the EU marker residue definition at the required levels of sensitivity for official control of florfenicol residues in animal tissue (authorised use) or milk (unauthorised use). Comprehensive withdrawal study data on analysis of tissue or milk samples from treated animals is presented. The data supports use of the methods in residue control in relation to the antibiotic florfenicol, as significant tissue bound and/or conjugated residues were detected, with bound residues predominant in the case of animal tissue matrices. A robust, multi-residue confirmatory method for antibiotic residues in animal tissue (kidney) and milk is presented. Rapid quantitative LC-MS/MS testing of up to 72 antimicrobials across 10 different antibiotic classes is achieved in 8 minutes per sample, offering improvements in scope and speed for the analysis of antimicrobials in products of animal origin.The work addresses key analytical challenges encountered by official laboratories and contributes to further refinement of quantitative approaches. It is hoped that the data and methods presented in this thesis will contribute to further discussions in the control of antimicrobial residues in food and inform testing laboratories on appropriate analysis methods for official control.

Thesis embargoed until 31st December 2026

Date of Award	Dec 2024
Original language	English
Awarding Institution	Queen's University Belfast
Supervisor	Christopher Elliott (Supervisor)