Preparation of anti-salbutamol antibody based on a new designed immunogen and development of a heterologous indirect ELISA for detection of salbutamol residue

To synthesize salbutamol immunogen and develop an enzyme immunoassay (ELISA), a new  salbutamol immunogen was synthesized using 4-aminobenzoic acid as a linker to connect hapten with carrier protein.  An enzyme immunoassay based on the antibody prepared was developed and applied to detect     salbutamol residue spiked in swine liver.  An unusual coating antigen, clenbuterol-ovalbumin (OVA) conjugate instead of salbutamol-OVA conjugate, was used in the immunoassay and the results were discussed based on the structures of related compounds.  The antibodies showed high sensitivity in the heterologous assay when using clenbuterol-OVA as a coating antigen, with an IC₅₀ value of 8.97 ng·mL⁻¹ toward salbutamol.  The antibodies prepared showed high cross-reactivity with clenbuterol (107%) and were promising for the simultaneous     determination of salbutamol and clenbuterol residues in food and food products.  Recovery rates from the   salbutamol-spiked swine liver samples were in the range of 70%−99%, while the intra-assay and inter-assay   coefficients of variation were <13.3% and <14.3%, respectively.  In summary, the antibodies of salbutamol have been successfully prepared.  Sensitive and stable analysis for the detection of salbutamol residues in swine liver was obtained based on the competitive ELISA methods developed in this study.