Analytical strategies for the screening of veterinary drugs and their residues in edible products.

The development of analytical strategies for the regulatory control of drug residues in food-producing animals is discussed. Analytical methods for the determination of veterinary drugs in edible products are based on microbiological, immunochemical and physicochemical principles. Because of complexity of biological matrices such as egg, milk and meat, well designed, and often sophisticated, off-line or on-line sample treatment procedures are essential, especially when utilising physicochemical multi-residue screening procedures. Since large series of samples have often to be analysed, automation is increasingly becoming important. Confirmation of the identity of drug residues and validation of the analytical results implies the use of adequate analytical methods. In its turn, this requires well established criteria for those methods and/or equivalent reference methods.