Determination of ivermectin B1a in animal plasma by liquid chromatography combined with electrospray ionization mass spectrometry

✍ Scribed by S. Croubels; S. De Baere; M. Cherlet; P. De Backer

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 229 KB
• Volume: 37
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.343

✦ Synopsis

Abstract

A novel, sensitive and specific method for the quantitative determination of ivermectin B~1a~ in animal plasma using liquid chromatography combined with positive electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) is presented. Abamectin was used as the internal standard. Extraction of the samples was performed with a deproteinization step using acetonitrile. Chromatographic separation was achieved on a Nucleosil ODS 5 µm column, using gradient elution with 0.2% (v/v) acetic acid in water and 0.2% (v/v) acetic acid in acetonitrile. The method was validated according to the requirements defined by the European Community. Calibration curves using plasma fortified between 1 and 100 ng ml^−1^ showed a good linear correlation (r ≥ 0.9989, goodness‐of‐fit coefficient ≤8.1%). The trueness at 2 and 25 ng ml^−1^ (n = 6) was +4.2 and −17.1%, respectively. The trueness and between‐run precision for the analysis of quality control samples at 25 ng ml^−1^ was −4.0 and 11.0%, respectively (n = 16). The limit of quantification of the method was 1.0 ng ml^−1^, for which the trueness and precision also fell within acceptable limits. Using a signal‐to‐noise ratio of 3 : 1, the limit of detection was calculated to be 0.2 ng ml^−1^. The specificity was demonstrated with respect to ivermectin B~1b~.

The method was successfully used for the quantitative determination of ivermectin B~1a~ in plasma samples from treated bovines, demonstrating the usefulness of the developed method for application in the field of pharmacokinetics. Copyright © 2002 John Wiley & Sons, Ltd.