In-house quality control material of nicarbazin and narasin in eggs: preparation and inter-laboratory evaluation

摘要: Coccidiostats are a group of pharmacologically active substances widely used in veterinary practice. Their residues detected relatively often poultry tissues and egg samples analyzed as part official residue control programs the European Union. Therefore, accuracy quantitative results needs to be monitored through internal external quality studies. In addition, use materials containing incurred would welcome for ongoing monitoring method accuracy. Unfortunately, field drug residues, certified reference unavailable. in-house material lyophilized eggs narasin nicarbazin has been produced characterized. The originated from hens receiving feed with coccidiostat premix Maxiban were mixed obtain presumed concentrations freeze-dried. Homogeneity was verified by duplicate analysis ten random samples, proved that between variation negligible comparison repeatability. No measurable loss analytes observed within 1 year; slope regression line stability measurements not significantly different zero. assigned values expressed medians inter-laboratory performed four laboratories; uncertainty estimated, taken into consideration all above tests, resulting (14.4 ± 2.53) µg/kg (7.91 1.52) narasin.