A preliminary study of simultaneous veterinary drug and pesticide residues in eggs produced in organic and cage-free alternative systems using LC-MS/MS.

In this study, a preliminary food quality and safety assessment was performed on organic and cage-free egg samples marketed in the state of Rio de Janeiro, Brazil, that were analyzed concerning veterinary drug and pesticide residues using high performance and ultra performance liquid chromatography coupled to tandem mass spectrometry. The polyether ionophore salinomycin was detected in two organic egg samples (25% of the organic samples), one with an estimated concentration even higher than the maximum permissible amount of 3 µg kg established for conventional eggs by the European Commission. The other sample presented a concentration higher than the limit of detection of 0.