Validation of a streamlined multiclass, multiresidue method for determination of veterinary drug residues in bovine muscle by liquid chromatography-tandem mass spectrometry

Authors: Schneider, Marilyn; Lehotay, Steven; Lightfield, Alan

Submitted to: Analytical and Bioanalytical Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2014
Publication Date: 12/27/2014
Publication URL: http://handle.nal.usda.gov/10113/61044
Citation: Schneider, M.J., Lehotay, S.J., Lightfield, A.R. 2014. Validation of a streamlined multiclass, multiresidue method for determination of veterinary drug residues in bovine muscle by liquid chromatography-tandem mass spectrometry. Analytical and Bioanalytical Chemistry. DOI:10.1007/s00216-014-8386-3.

Interpretive Summary: The use of veterinary drugs in food animals requires monitoring of the food supply to ensure that any remaining drug residues are below the tolerance levels set by the U. S. Food and Drug Administration. Due to the number and variety of drugs available, multiclass multiresidue methods are increasingly being developed for monitoring purposes. While such methods are inherently more efficient than using a separate method for each potential drug residue, they often require time consuming processes such as evaporation of extracts to produce a more concentrated sample for analysis. We have now developed and validated a multiclass multiresidue method for veterinary drugs in bovine muscle which combines cleanup and filtration into one step, and does not require evaporation of extracts. This streamlined method was found to give excellent results for 100 drugs and thus provides regulatory agencies such as the U.S. Food Safety and Inspection Service with a new, highly efficient approach for monitoring veterinary drug residues in food.

Technical Abstract: Multiclass, multiresidue methods are becoming increasingly popular in regulatory monitoring programs due to their increased analytical scope and laboratory efficiency. In this work, we report the development and validation of a new high-throughput analytical method to monitor up to 131 veterinary drug residues, representing at least 13 different classes, in bovine muscle. This novel method streamlined sample preparation to less than 15 min/sample/analyst, or a batch of 40-60 pre-homogenized samples in less than 3 hr/analyst, through the combination of dispersive solid-phase extraction with in-vial filtration (a new technique known as filter-vial d-SPE). The use of an enhanced sensitivity state-of-the-art tandem mass spectrometer led to less than 10 ng/g limits of quantification for nearly all drug analytes with injection of 0.17 mg of equivalent sample. Positive and negative switching in electrospray ionization was applied to cover all analytes in an 11 min liquid chromatographic separation. In the 3-day validation study, 100 of the drugs met quantification criteria of 70-120% recoveries and Horwitz Ratio less than greater than 1.0, and the remaining analytes could still be screened at regulatory target levels.