Feed additives diclazuril and nicarbazin in egg and liver samples from Croatian farms

In total 307 egg and 275 liver samples were examined for nicarbazin and 365 eggs for diclazuril over a 30-month period. Enzyme-linked immunosorbent assay methods used for quantification were validated according to European Commission Decision 2002/657/EC. Non-compliant samples were confirmed by LC-MS/MS. Mean diclazuril concentrations in egg samples were 0.31 µg kg⁻¹, which is below the MRL. In only one egg sample, 2.26 µg kg⁻¹ was determined by enzyme-linked immunosorbent assay, although confirmation by LC-MS/MS gave a value of 1.6 µg kg(-1). Mean nicarbazin levels determined were 1.85 µg kg⁻¹ in egg and 21.1 µg kg⁻¹ in liver samples. Four samples, one egg and three livers, yielded elevated concentrations of nicarbazin, but only in the egg sample the LC-MS/MS method confirmed nicarbazin (106 µg kg⁻¹) above the MRL value.