Document Type

Theses, Ph.D

Rights

Available under a Creative Commons Attribution Non-Commercial Share Alike 4.0 International Licence

Disciplines

Pharmacology and pharmacy, 4.3 VETERINARY SCIENCE

Publication Details

Thesis submitted in fulfilment of requirement leading to the award of the degree of Doctor of Philosophy on the Basis of Publication, May 2012.

Abstract

Abstract

Today, in modern farming practices veterinary drugs are given to food-producing animals. The generic term “veterinary drugs” covers a broad variety of classes of chemical compounds and the list of drugs is enormous and it is a significant analytical challenge in regulatory control to provide monitoring programmes. The major concerns in veterinary drug usage are the presence of harmful residues that may be introduced into the human food chain. The aim of this research is the development of analytical methods capable of screening and confirming increased numbers of these residues in target matrices by Gas Chromatography Tandem Mass Spectrometry (GC-MS/MS) and Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS). The focus is on Non-Steroidal Anti Inflammatory Drugs (NSAIDs) residues in food of animal origin. The research resulted in the development and validation of methods for the analysis of NSAIDs in milk. The second topic under investigation was in the field of post-mortem forensic toxicology. Forensic toxicological activities are important in society and great efforts to implement rapid analytical procedures in a forensically credible manner is continuous across the globe. The main objectives of the research work in post-mortem forensic toxicology were to address the issues concerning the availability of rapid novel unequivocal confirmatory analytical methodologies for forensically important drugs. The aim of this work was to develop single fast, simple and reliable sample preparation procedures in blood and urine with detection by hybrid LC-MS as analytical strategies in a forensic laboratory for the determination of drugs of abuse in this study which were previously not available. All analytical methodologies developed in blood, milk and urine matrices were validated in accordance with EU legislation; Commission Decision 2002/657/EC. This validation legislation is concerned with the interpretation of results and the performance of analytical methods. Validation criteria were examined using protocols laid down in this legislation. These included specificity, accuracy, precision, repeatability, reproducibility, decision limits (CCa), detection capabilities (CCb) and in addition measurement uncertainty (MU). The methods developed for the NSAIDs residues in milk had accuracies ranging from 73-109 % and the precision for all analytes ranged from 2-30%. The CCa and the CCb values ranged from 0.46-0.79 ng mL-1 and the MU ranged from 9-90%. The methods developed for the forensically important drugs in blood and urine had accuracies ranging from 80-113% and the precision for all analytes ranged from 4-22%. The CCa and the CCb values ranged from 0.005-0.05 ug mL-1 and the MU ranged from 13-47%. To ensure that methods were suitable for purpose the methods were evaluated in international proficiency testing schemes and results were satisfactory. In addition some of the methods were accredited in accordance with ISO17025 guidelines. A number of different analysts were trained on the new methodologies developed in this work thus providing further evidence of the development of rugged analytical methods and satisfactory results were obtained using quality control material. In addition the methods have replaced previous methods in The State Laboratory for the monitoring of NSAIDs and are used routinely at present in theRepublic ofIreland in national monitoring programmes. The methods developed for blood and urine in the forensic toxicology section of this thesis have replaced previous methods in national forensic toxicology monitoring programmes in the past number of years at The State Laboratory and are used in toxicology testing for the law courts in forensic and Coroner’s cases in Ireland. The method in this thesis for forensic drugs in blood is submitted for accreditation in 2012 as satisfactory results were obtained using quality control and international proficiency test samples in the past number of years.

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