ABSTRACT
The potent antiparasitic ivermectin is detected at low concentrations (ng/g) in liver and muscle tissue by liquid chromatography after conversion to a fluorescent derivative with 1-methylimidazole and trifluoroacetic anhydride. This acetylation reaction can be compromised by residual water that leads to decreased yields. Yields of derivatives of ivermectin and abamectin, a related avermectin, are identical under all circumstances tested. Use of abamectin as an internal standard eliminates derivative yield as a source of analytical variation.
Subject(s)
Anthelmintics/analysis , Ivermectin/analysis , Chromatography, Liquid , Indicators and Reagents , Ivermectin/analogs & derivatives , Liver/chemistry , Muscles/chemistry , Reference Standards , Spectrometry, FluorescenceABSTRACT
Extraction of liver tissue with organic solvent produces coextractants with compounds of interest. The solid-phase extraction (SPE) cleanup of liver tissue developed for ivermectin removes nonpolar coextractants. Liver extract that has been reduced to dryness is reconstituted in 0.5 mL acetonitrile. The mixture is passed through 0.1 g C18 SPE column, and the eluate is collected. The column is eluted further with 2 mL acetonitrile. Combined eluates are derivatized with 1-methylimidazole and trifluoroacetic anhydride, and the ivermectin derivative is determined by liquid chromatography with fluorescence detection.
