Development and Validation of a Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay for Salinomycin in Chicken Liver Tissue

Salinomycin is one of the most widely used coccidiostats in U.S. agriculture. A rapid and accurate analytical method for this drug should provide producers and users with an effective management tool. The current chromatographic methods are sensitive but are labor-intensive. In addition, they require large amounts of expensive organic solvents for extraction and cleanup, which requires proper (and expensive) disposal. This paper reports the development of an enzyme-linked immunosorbent assay (ELISA) coupled to a simple aqueous extraction procedure for the analysis of salinomycin in chicken liver tissue. Recovery from spiked liver homogenates was quantitative in the range from 5.0 to 0.05 ppm. Analysis of chicken livers containing incurred residue by ELISA and high-performance liquid chromatography (HPLC) showed the results to be highly correlated (p < 0.0001). The ELISA method described here has a limit of quantitation of 50 ppb, which is more sensitive than the HPLC method.