Procedure 34 Electrochemical determination of sulfonamide antibiotics in milk samples using a class-selective antibody

Abstract

Publisher Summary This chapter presents a method for the purification of the specific anti-sulfonamide antibody, for the construction of a magneto graphite–epoxy composite (m-GEC) electrode, for the immobilization of the specific anti-sulfonamide antibody on Tosyl-modified magnetic beads, and for the quantification of sulfonamide antibiotics in milk based on its immunological reaction with the class-selective specific antibody by using an electrochemical strategy based on magnetic beads and m-GEC electrode. To purify the anti-sulfonamide class-specific antibodies, 45% saturated solution is obtained by adding ammonium sulfate dropwise in 3 mL of immune and preimmune antisera of immunized and nonimmunized New Zealand white rabbits. The supernatant is separated after 4 h from the solid by centrifugation. The solution is filtered. Finally, the antibodies are dialyzed and lyophilized. To evaluate the antibody binding Bradford test is used. Electrochemical determination of sulfonamide in milk includes construction of the standard sulfonamide curve in PBST and in milk.