Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2017
Publication Date: N/A
Interpretive Summary: .
Technical Abstract: Zilpaterol is a beta-adrenergic agonist feed additive approved in the United States to increase weight gain and improve feed efficiency of cattle. Countries which ban beta-adrenergic agonist feed additives can reject imported beef products that contain zilpaterol. Therefore, efficient, portable, and user friendly screening assays towards zilpaterol are needed. In this report, an immunochromatographic assay was developed for the rapid detection of zilpaterol. Zilpaterol-butyrate BSA was plotted onto nitrocellulose membrane while colloidal gold labeled with zilpaterol antibody was adsorbed to a glass fiber sample pad. The assay was applied to cattle feed and cattle urine, horse urine, sheep muscle and sheep urine with sensitivities of 19.2, 1.7, 8.8, 5.8, and 1.7 ng/g or ng/mL, respectively. No sample preparation was needed for cattle and sheep urine, but horse urine and cattle feed required dilution; muscle required solvent extraction. The zilpaterol immunochromatographic assay was tested with incurred horse urine, sheep urine, and sheep muscle. Of the 61 incurred sheep urine samples, all zilpaterol treatment samples were correctly identified but 2 false-positives occurred compared to LC-MS results. Incurred horse urine containing zilpaterol residue > 10 ppb (~ withdrawal day 6) were correctly identified as positives by the immunochromatographic assay. The immunochromatographic assay correctly identified 0-day withdrawal muscle samples as positive and the control sheep as negative. In conclusion, the developed zilpaterol immunochromatographic assay is useful for on-site, portable testing of urine and feed samples and screening of meat samples.