An Indirect Competitive Enzyme-linked Immunosorbent Assay for Simultaneous Determination of Florfenicol and Thiamphenicol in Animal Meat and Urine

A high-affinity polyclonal antibody was prepared by immunizing animals with haptens FFD and FFM. Under the optimal combination of coating antigen and antibody, an indirect competitive enzyme-linked immunosorbent assay (icELISA) for simultaneous detection of florfenicol and thiamphenicol residues in animal meat and urine samples was developed. The icELISA showed an IC 50 value of 1.32 ng mL −1 for florfenicol and 2.13 ng mL −1 for thiamphenicol, respectively. The linear ranges were from 0.31 to 5.61 ng mL −1 with a limit of detection of 0.12 ng mL −1 for florfenicol, and 0.41 to 11.2 ng mL −1 with a limit of detection of 0.15 ng mL −1 for thiamphenicol, respectively. The average recoveries of florfenicol and thiamphenicol in spiked samples ranged from 77.2% to 116.0% with a relative standard deviation of less than 15%. Therefore, this proposed icELISA provided a valid detection method for florfenicol and thiamphenicol residues in animal tissue and urine samples.