Analytical methodologies for the detection of β-lactam antibiotics in milk and feed samples

Antibiotic residues in milk are of great concern to dairy farmers, milk processors, regulatory agencies and consumers. In addition, the effectiveness of antibiotics is threatened by extensive, inappropriate use. In veterinary practice, antibiotics are utilized at therapeutic levels primarily to treat diseases and to prevent infections. They are also used at sub-therapeutic levels to increase feed efficiency and to promote growth in food-producing animals. The frequent, sometimes illegal, use of antibiotics may result in residues being found at different concentration levels in products of animal origin, such as milk. β-lactams comprise some of the antibiotics most frequently used for the treatment of sick animals in Europe. This review presents analytical methods that have been developed during the past decade for penicillin and cephalosporin residues in milk and feed samples. It includes microbiological approaches, biosensors, immunochemical techniques and chromatographic methods.