Validation of an enzyme-linked immunosorbent assay screening for quinolones in egg, poultry muscle and feed samples.

Quinolones are a group of chemotherapeutic agents with an excellent efficiency against poultry pathogens. Two commercial enzyme-linked immunosorbent assay (ELISA) tests have been applied in parallel for the qualitative screening analysis of several quinolones in eggs, poultry muscle and feeds at the required levels. During the validation study, carried out according to the Commission Decision 2002/657/EC criteria, two different sample treatments were compared in foods: the simple and fast procedure suggested by the kit producer (Euro-Diagnostica) and a more complex solid-phase extraction (SPE) sample preparation. The results demonstrated that the method based on SPE clean up exhibited better characteristic performances, particularly in eggs for which lower detection levels are required. Despite the fact that screening methods should be rapid and cheap, the use of non-chromatographic techniques such as ELISA for multiresidual detection of a class of substances involves some additional attention to sample preparation.