Development and Validation of a Sensitive Indirect Competitive Enzyme-Linked Immunosorbent Assay for the Screening of Florfenicol and Thiamphenicol in Edible Animal Tissue and Feed

To monitor the illegal use of florfenicol (FF) and thiamphenicol (TAP) in edible animal tissue and feed, a sensitive monoclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) has been developed with simple sample preparation and cleanup. The obtained monoclonal antibody (5F4) that has isotype IgG1 showed an IC50 value of 0.21 mu g L-1 for FF and 0.35 mu g L-1 for TAP, respectively. It did not exhibit measurable cross-reactivity with other antibiotics. The limits of detection (LODs) for FF and TAP in a muscle matrix ranged from 0.07 to 0.14 mu g kg(-1) and in a feed matrix ranged from 2.9 to 5.2 mu g kg(-1). The recoveries were 72.8 to 113.4 % with a coefficient of variation of less than 15 %. Good correlation between the ELISA and HPLC-MS/MS results in the tissues tested demonstrated the reliability of our ic-ELISA. This ELISA is a useful tool for screening FF and TAP in edible animal tissue and feed.