Preparation of Acetochlor Antibody and Its Application on Immunoaffinity Chromatography Cleanup for Residue Determination in Peanuts

The preparation of an antibody against acetochlor and its application on immunoaffinity chromatography (IAC) cleanup was investigated. The hapten was synthesized by reacting acetochlor with 3-mercaptopropionic acid and then linked with a carrier protein by the carbodiimide method. After immunizing a rabbit with hapten-bovine serum albumin (BSA) conjugate, the obtained antiserum showed an IC50 value of 0.2 ng/mL. By coupling the purified polyclonal antibody with CNBr-activated Sepharose 4B, an IAC column was prepared. The dynamic column capacity was 5560 ng/mL gel. The IAC was then used to clean up a peanut sample solution, followed by high-performance liquid chromatography (HPLC) separation and ultraviolet (UV) detection. The recoveries of acetochlor from spiked peanut samples at levels of 5-100 mu g/kg ranged from 94.7 to 102.5%, with a variation coefficient of 2.6-8.0%, and the limits of detection and quantification were 1.5 and 5 mu g/kg, respectively.