A rapid and sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method to quantify thiamphenicol (TAP), florfenicol (FF), and florfenicol amine (FFA) in swine muscle is described. An immunoaffinity chromatography (IAC) column based on polyclonal antibodies and protein A-sepharose CL 4B was used to clean-up extracted samples. IAC optimized conditions were found that allowed the IAC to be reused for selective binding of TAP, FF, and FFA. The dynamic column capacity was more than 512ng/mL of gel after being used for 15 cycles. From fortified swine muscle samples at levels of 0.4-50ng/g, the average recoveries were 85.2-98.9% with intra- and inter-day variations less than 9.8% and 12.4%, respectively. The limit of quantitation ranged from 0.4 to 4.0microg/kg.