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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Food Animal Metabolism Research » Research » Publications at this Location » Publication #291743
Title: Comparison of ELISA and LC-MS/MS for the measurement of flunixin plasma concentrations in beef cattle after intravenous and subcutaneous administration

Author
item Shelver, Weilin
item TELL, LISA - University Of California
item WAGNER, SARAH - North Dakota State University
item WETZLICH, SCOTT - University Of California
item BAYNES, RONALD - North Carolina State University
item RIVIERE, JIM - Kansas State University
item Smith, David

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2013
Publication Date: 8/26/2013
Citation: Shelver, W.L., Tell, L.A., Wagner, S., Wetzlich, S.E., Baynes, R.E., Riviere, J.E., Smith, D.J. 2013. Comparison of ELISA and LC-MS/MS for the measurement of flunixin plasma concentrations in beef cattle after intravenous and subcutaneous administration [abstract]. Association of Analytical Communities Annual Meeting & Exposition. Poster No. P-M-047.

Interpretive Summary:

Technical Abstract: Eight cattle (288 +/- 22 kg) were treated with 2.2 mg/kg of flunixin in a cross-over design using subcutaneous (SC) and intravenous (IV) administration. The limit of detection (LOD) was 0.42 ng/mL and the working range was 0.76 - 66.4 ng/mL for ELISA when adjusted for dilution. The linear calibration curve for LC-MS/MS was 0.5 – 2000 ng/mL with a LOD of 0.1 ng/mL for flunixin and 0.3 ng/mL for 5-OH flunixin. Pharmacokinetic parameters of time vs. concentration data from ELISA and LC-MS/MS were estimated and compared. Differences (P < 0.05) in estimates of area under the curve, volume of distribution, and clearance were apparent between ELISA and LC-MS/MS analyses after IV dosing but not with SC dosing. Nevertheless, it would be difficult to differentiate routes of administration in healthy cattle based on the plasma elimination profiles of flunixin after IV or SC dosing.