In-house validation of an ELISA method for screening of semicarbazide in eggs
Résumé
An enzyme-linked immunosorbent assay (ELISA) method is described for the semi-quantitative determination of semicarbazide (SEM), the marker residue for the banned nitrofuran drug nitrofurazone, in chicken eggs. The sample homogenate is subjected to acid hydrolysis and derivatisation with o-nitrobenzaldehyde, followed by ethyl acetate / hexane extraction and detection by ELISA. The ELISA procedure has been validated using 0.3, 1.0 and 3 μg Kg-1 of SEM in fortified samples. Detection capability (CCß) was set on the basis of the acceptance of 5 % false compliant results for a given concentration level according to Commission Decision 2002/657/EC, and was determined to be 0.3 μg Kg-1 with a respective limit of detection of 0.13 μg Kg-1. A validated LC-MS/MS method was used for the analysis of incurred egg samples and the results compared with ELISA. A good correlation between the results obtained from ELISA and LC-MS/MS within the concentration range 0.12 to 20.3 μg Kg-1 was observed in samples collected from chickens fed with a medicated ration of nitrofurazone (r = 0.992, n = 14). Validated ELISA enabled reliable monitoring of SEM levels in eggs collected from incurred chickens for a 90 day period.
Origine : Fichiers produits par l'(les) auteur(s)