@article{MAKHILLJAVA200873442,
    title = {Determination of Ractopamine in Swine Feed and Urine Using an Indirect Competitive Immunoassay},
    journal = {Journal of Animal and Veterinary Advances},
    volume = {7},
    number = {3},
    pages = {268-275},
    year = {2008},
    issn = {1680-5593},
    doi = {javaa.2008.268.275},
    url = {https://makhillpublications.co/view-article.php?issn=1680-5593&doi=javaa.2008.268.275},
    author = {Pingli He,Liying Zhang and},
    keywords = {Ractopamine,ELISA,liquid chromatography-mass spectrometry,feeds,urine},
    abstract = {Anti-ractopamine polyclonal antisera were prepared by coupling ractopamine to bovine thyroglobulin and human serum albumin using two different methods. A systematic study of cross-reactions with eleven related compounds showed that the antibodies had a high specificity for ractopamine. Using the purified antiserum  R3, an indirect competitive immunoassay for the determination of ractopamine in swine feed and urine was established and a typical competition calibration curve showed good sensitivity of 0.8 ng mL <SUP>1</SUP>, estimated as the value of IC<SUB>50</SUB>, with a practical working range between 0.2 and 3 ng mL <SUP>1</SUP>, the limit of detection of 0.15 ng mL <SUP>1</SUP>. Finally, this assay was applied to the analysis of ractopamine in spiked swine feed and urine. The  average  recoveries  of  ractopamine were between 80-120% and the coefficients of variations were  less than 10%. The results were also confirmed by liquid chromatography-mass spectrometry, which showed good agreement (r<SUP>2</SUP> = 0.997) with the established immunoassay.}
    }