TY  - JOUR
T1  - Determination of Ractopamine in Swine Feed and Urine Using an Indirect Competitive Immunoassay
AU - , Pingli He AU - , Liying Zhang AU - , Tangbin Yang 
JO  - Journal of Animal and Veterinary Advances
VL  - 7
IS  - 3
SP  - 268
EP  - 275
PY  - 2008
DA  - 2001/08/19
SN  - 1680-5593
DO  - javaa.2008.268.275
UR  - https://makhillpublications.co/view-article.php?doi=javaa.2008.268.275
KW  - Ractopamine
KW  -ELISA
KW  -liquid chromatography-mass spectrometry
KW  -feeds
KW  -urine
AB  - 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.
ER  -