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ARS Home » Plains Area » Kerrville, Texas » Knipling-Bushland U.S. Livestock Insects Research Laboratory » Cattle Fever Tick Research Unit » Research » Publications at this Location » Publication #415086
Research Project: Integrated Pest Management of Cattle Fever Ticks

Location: Cattle Fever Tick Research Unit

Title: Development of an analytical method for the analysis of diflubenzuron in whole blood, plasma, and serum using liquid chromatography tandem mass spectrometry

Author
item JELLICK, GREG - University Of Texas At San Antonio
item Lohmeyer, Kimberly
item BACH, STEPHEN - University Of Texas At San Antonio

Submitted to: Journal of Chromatography B
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2025
Publication Date: 4/15/2025
Citation: Jellick, G., Lohmeyer, K.H., Bach, S. 2025. Development of an analytical method for the analysis of diflubenzuron in whole blood, plasma, and serum using liquid chromatography tandem mass spectrometry. Journal of Chromatography B. https://doi.org/10.1016/j.jchromb.2025.124506.
DOI: https://doi.org/10.1016/j.jchromb.2025.124506

Interpretive Summary: Babesiosis can be spread among naive cattle by cattle fever ticks (CFT). Although eliminated from the US in the 1940s, CFT and babesiosis are endemic to Mexico, Central and South America. CFT continue to infiltrate the US by crossing the Texas/Mexico border on stray livestock and wildlife including white-tailed deer (WTD). Orally administered acaricides are a part of the strategy to control CFT. Parallel dosing studies utilizing oral administration of diflubenzuron (DFB) were conducted in cattle and white-tailed deer. We developed and validated a liquid chromatography/tandem mass spectrometry (LC-MS/MS) method for analysis of the studies’ samples. This paper outlines the extraction and instrumental method for DFB analysis in whole blood, plasma, and serum. LC-MS/MS had not previously been used to detect DFB in whole blood, plasma, or serum, or in a bovine dosing study.

Technical Abstract: The integration of free-range beef livestock into the human food chain has been continuously threatened by outbreaks of babesiosis, which is propagated by ticks that vector the protozoans that cause the disease. The protozoans are spread among livestock by certain species of ticks, known collectively as cattle fever ticks (CFT). Although eliminated from the US in the 1940s, CFT continue to infiltrate the US by crossing the US/Mexico border on stray livestock and wildlife, and infest cattle herds. Orally administered acaricides are part of the strategy to control CFT. Parallel dosing studies, utilizing oral administration of the benzoylphenyl urea (BPU) compound diflubenzuron (DFB), were conducted in cattle and white-tailed deer (WTD). We developed and validated a sensitive (<1'ppb) liquid chromatography/ tandem mass spectrometry (LC-MS/MS) method for DFB quantification in toxicology specimens. In a fit-for-purpose testing, the method demonstrated accuracies within ±9'% of QC targets, and coefficient of variation percentages (%CV) of 14.8'% for whole blood, 9.0'% for plasma, and 8.7'% for serum. This work outlines the extraction and instrumental method for DFB analysis in these matrices. LC-MS/MS had not previously been used to detect and quantify DFB in whole blood, plasma, or serum. This is also the first method to employ carbon-13 labeled DFB (13C6) as an internal standard for measuring DFB in blood matrices from bovine dosing studies.