Development and Application of Immunoaffinity Column for the Simultaneous Determination of Norfloxacin, Pefloxacin, Lomefloxacin, and Enrofloxacin in Swine and Chicken Meat Samples

Immunoaffinity chromatography (IAC) for simultaneous determination of four fluoroquinolone antibiotics, e.g., norfloxacin (NOR), pefloxacin (PEF), lomefloxacin (LOM), and enrofloxacin (ENRO) from swine and chicken meat samples, was developed. The IAC column was constructed by covalently coupling polyclonal antibody (pAb) against NOR to cyanogen bromide (CNBr)-activated Sepharose 4B and packed into a common solid-phase extraction (SPE) cartridge. It was found that IAC column was able to separately capture NOR, PEF, LOM, and ENRO with a maximum capacity of 200, 336, 352, and 421 ng, respectively. The extraction conditions including loading, washing, and eluting solutions were carefully optimized. Under optimal conditions, the extraction recoveries of the IAC column for NOR, PEF, LOM, and ENRO at two different contents were within 85.8–105.9 %. The IAC column was also applied to real sample extraction. Swine and chicken meat samples were collected and spiked with NOR, PEF, LOM, and ENRO at the content of 20 and 35 ng g −1 , respectively. The spiked and unspiked samples were extracted by IAC column and measured by high-performance liquid chromatography (HPLC). It was found that there was no detectable NOR, PEF, LOM, and ENRO in the blank samples, and the extraction recoveries of the IAC for NOR, PEF, LOM, and ENRO from the spiked samples were within 75.3–99.8 % with the relative standard deviation (RSD) of 4.3–12.1 %. The stability of the column was also tested. It was showed that after 30 times repeated usage, 65 % of the maximum capacity was still remained, indicating high reusability of the IAC column. The proposed IAC was proven to be an effectively selective extraction method for NOR, PEF, LOM, and ENRO from swine and chicken meat samples with the properties of high maximum capacity, extraction efficiency, and stability.