ARS | Publication request: Time-resolved luminescence screening method for enrofloxacin in beef serum

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2010
Publication Date: June 1, 2010
Citation: Schneider, M.J., Yun, L., Lehotay, S.J. 2010. Time-resolved luminescence screening method for enrofloxacin in beef serum [Abstract]. 31.

Technical Abstract: Enrofloxacin is one of only two fluoroquinolone antibiotics approved for use in cattle in the U.S. Microbial screening methods currently used in the U.S. for monitoring veterinary drug residues are not sensitive or selective for fluoroquinolones. In this work, a luminescence-based screening assay was developed to detect enrofloxacin in beef serum. The choice of serum as a matrix allows for either ante- or post-mortem use. This approach takes advantage of the DNA-enhanced time-resolved luminescence signal of an enrofloxacin-Tb+3 complex. In the method, serum samples are extracted with acidic acetonitrile in the presence of magnesium sulfate. Evaporation of the supernatant is followed by dissolution of the residue in buffer and filtration. Addition of DNA then allows for reading of the time-resolved luminescence. Good recoveries (73-88%) at 25, 50, and 100 ng/g were achieved with this approach, and the limit of detection was found to be 2.5 ng/g based on control samples from 18 different steers. The method was used to test quantitative screening over a range of 0-100 ng/g using blind samples.