J AOAC Int. 2022 Sep 14:qsac104. doi: 10.1093/jaoacint/qsac104. Online ahead of print.
ABSTRACT
BACKGROUND: Oxytetracycline, chlortetracycline, and tetracycline are approved antibiotics used to treat bacterial infections in cattle. To ensure human food safety, a tolerance has been established for the sum of these three tetracycline residues as 12 ppm in bovine kidney in the U.S. The current official regulatory method for quantifying these antibiotics in the target organ is a labor-intensive microbiological assay.
OBJECTIVE: Our laboratory developed and validated a fast, selective and less laborious method utilizing liquid chromatography-tandem mass spectrometry for the determination and confirmation of the three tetracyclines in bovine kidney.
METHODS: Briefly, homogenized kidney tissue was spiked with an internal standard, and then was extracted with 1% phosphate buffer. The crude extract was cleaned up using solid-phase extraction cartridges before instrumental analysis.
RESULTS: Accuracies for quantifying these three drugs in fortified kidney homogenate were between 99.9% and 110% at multiple concentrations, with respective coefficients of variation all below 9.5%. Quantitative correlation between the two methods (bridging) was evaluated with incurred bovine kidney samples for each of the three tetracyclines separately. The results were statistically evaluated using a measurement model called Functional Relationship Estimation by Maximum Likelihood.
CONCLUSIONS: A linear quantitative relationship was demonstrated between the two methods within the concentration range of regulatory relevance.
HIGHLIGHTS: This instrumental method is in addition to the established microbial assay for the detection of tetracyclines residue in beef kidney to ensure the food safety of cattle products.
PMID:36103709 | DOI:10.1093/jaoacint/qsac104
