Multi-Detection of Veterinary Medicines in Animal Feed for Production: A Review

Background/Objectives: The inappropriate use of veterinary medicines in feed for food-producing animals can compromise food safety. Intensive animal production is associated with the inappropriate use of antibiotics in feed, at subtherapeutic concentrations, to promote animal growth. It is therefore crucial to develop an effective multi-detection method to ensure that this feed complies with the requirements of European Commission Regulations. This control is essential to ensure consumer protection, as adequate supervision contributes to reducing antimicrobial resistance, a growing concern worldwide. Methods: A literature search was conducted using scientific databases, namely PubMed, ScienceDirect, Scopus and Google Scholar, as well as European Union Regulations. Results: It was observed that the most used standard solution solvents are methanol, acetonitrile, ultrapure water, or mixtures of these solvents. For extraction, the most frequently used solvents include trichloroacetic acid combined with McIlvaine buffer or with acetonitrile, and acetonitrile or methanol combined with formic acid or with ethylenediaminetetraacetic acid disodium (Na₂EDTA). For extraction and purification of the analyte, several steps were verified, such as solid-phase extraction (SPE), dispersive solid-phase extraction (d-SPE), liquid-liquid extraction (LLE), Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS), protein precipitation through freezing and dilution prior to analysis. Liquid chromatography coupled with mass spectrometry is the preferred choice, especially for multiple detection methods. Conclusions: Based on this data, the foundation is established for the development of an appropriate method for the simultaneous extraction of multiple classes of antibiotics, which is applicable to feed different food-production animals.