U.S. Department of Agriculture: Animal and Plant Health Inspection Service
Date of this Version
May 2004
Abstract
An analytical method is required for the analysis of monoterpenes in animal plasma to support a pharmacokinetic study. Monoterpenes common to sagebrush are extracted from sheep plasma by employing solid-phase extraction (SPE), followed by analysis of the extracts by gas chromatography with flame ionization detection. The analytes are quantitated versus an external standard and by comparison with a surrogate standard added to the sample prior to extraction. In addition to comparing the two quantitative methods, the storage stability of the analytes in plasma and SPE columns is evaluated. Both methods employed for quantitation yield precision suitable for pharmacokinetic studies. However, determination of monoterpenes residues versus external standards produces improved accuracy as compared with use of the surrogate standard. Some analyte loss is observed from plasma samples stored for five weeks at –12°C. However, storage of extracts on the SPE columns affords excellent stability.
Comments
Published by Journal of Chromatographic Science, Vol. 42, May/June 2004.