###### Abstract  
In the last years, the European Commission has adopted restrictive directives on food quality and safety in order to protect animal and human health. Veterinary drugs represent an important risk and the need to have sensitive and fast analytical techniques to detect and quantify them has become mandatory. Over the years, the availability of different modes, interfaces, and formats has improved the versatility, sensitivity, and speed of capillary electrophoresis (CE) techniques. Thus, CE represents a powerful tool for the analysis of a large variety of food matrices and food-related molecules with important applications in food quality and safety. This review focuses the attention of CE applications over the last decade on the detection of different classes of drugs (used as additives in animal food or present as contaminants in food products) with a potential risk for animal and human health. In addition, considering that the different sample preparation procedures have strongly contributed to CE sensitivity and versatility, the most advanced sample pre-concentration techniques are discussed here. food quality; food safety; veterinary drugs; animal food; food contaminants; capillary electrophoresis; residue analysis; pre-concentration techniques +
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EU guidelines suggest the use of the liquid chromatography (LC) technique; in particular, LC coupled with mass spectrometry (MS) was the most used approach to detect and analyze drug residues in complex matrices, such as milk and dietary products [8; 9; 10; 11; 12]. In addition, ion mobility spectrometry (IMS) coupled with MS represented a very promising powerful tool to detect analytes in traces [13]. Capillary electrophoresis (CE) with its well-known advantages, such as high efficiency, low consumption of sample and buffer, and rapidity, represents a potential alternative to LC methods in the analysis of drugs in different fields, including food analysis [14; 15; 16]. Another important advantage of CE rests in the versatility of applications thanks to the development of different CE separation modes. The simple addition of different molecules (surfactants, chiral selectors, polymers, particular electrolytes, and organic modifiers) to the buffer or the modification of the capillary inner wall with new packaging materials gave origin to different separation mechanisms and selectivity, increasing CE versatility and potential applications [17; 18; 19; 16]. In particular, the use of electrospray ionization (ESI), matrix-assisted desorption/ionization (MALDI), and inductively coupled plasma (ICP) as CE-MS interfaces improved food analysis by increasing CE sensitivity [20; 21]. In fact, CE-MS represents the ideal technique to detect analytes in traces with important implications in food contaminants and residue analysis [15; 16]. In addition, advances in electrochemical detectors, such as CE-contactless coupled detection (CE-CCD) and CE-capacitively coupled contactless conductivity detection (CE-C\({}^{4}\)D), offered very sensitive methods [22; 23]. Furthermore, the development of miniaturized CE systems (microchip-CE devices) allowed the monitoring of food analytes with rapidity and sensitivity, and their use was particularly important in the detection of frauds or contaminations [24; 25; 26]. Due to the complexity of food matrices, which are mainly rich in lipids, carbohydrates, and proteins, a pre-concentration step was necessary to detect drug residues in trace amounts. This became mandatory because of the intrinsic poor sensitivity of CE [27]. Solid phase extraction (SPE) and miniaturized SPE are the most used procedures, not only for the pre-concentration step, but also for the sample clean-up. New SPE sorbents with high adsorption capacity and high resistance were studied, giving origin to selective materials for some drugs and also generating advanced high-throughput procedures able to extract different drug classes [28; 29].