Supervisors info:
Νικόλαος Θωμαΐδης, Καθηγητής, Τμήμα Χημείας, ΕΚΠΑ
Summary:
Veterinary drugs are widely used in animal husbandry not only for the prevention or treatment of diseases but also to achieve greater yield. A large number of veterinary drugs are administered for human diseases treatment. The consumer’s overexposure to these drugs and their residues can result in adverse effects on human health, such as antimicrobial resistance development, allergic reactions, toxic and potentially carcinogenic and teratogenic effects. While the EU regulates the use of coccidiostats and histomonostats, all the other categories of veterinary drugs remain out of monitoring and legislation framework. Since the most effective way of administration is their direct addition in the animal feed, it is important to be able to trace them in very low concentrations in that matrix. The most challenging part is the isolation of these drugs with substantially different physicochemical properties from the extremely complex matrix that is animal feed. The aim of this study was the development of a method for the determination of a wide variety of veterinary drugs, including tetracyclines, sulfonamides, quinolones, b-lactams, macrolides, benzimidazoles, amphenicols, anthelmintics and avermectins, among others, using Reversed Phase High Performance Liquid Chromatography-tandem Mass Spectrometry (RP HPLC-MS/MS). A thorough study was performed for the development and optimization of a sample preparation protocol. The final protocol comprised of a solid-liquid extraction using Ultrasonic-Assisted Extraction, followed by a three-step cleanup combining protein precipitation, hexane partitioning and Solid Phase Extraction (SPE). The method was validated in agreement with the guidelines of Commission Decision 2002/657/EC, yielding satisfactory results in terms of linearity, precision, intermediate precision and detectability for the majority of the studied compounds.
Keywords:
LC-MS/MS, residue analysis, veterinary drugs, animal feed, Reverse-Phase Chromatography
