title: Determination of fenbendazole and oxfendazole in liver and muscle using liquid chromatography-mass spectrometry.
abstract: A method has been developed for the determination of the anthelmintics fenbendazole and oxfendazole in liver and muscle samples using liquid chromatography-thermospray mass spectrometry (LC-MS). The samples were homogenized with water, sonicated with methanol and centrifuged. The supernatants were washed with light petroleum and extracted with diethyl ether-ethyl acetate. The extracts were evaporated to dryness, dissolved in mobile phase and injected into the LC-MS system. Fenbendazole and oxfendazole were measured separately using two different mobile phases. Single-ion monitoring of the positive ion at m/z 300 was used for fenbendazole and of m/z 316 for oxfendazole. The detection limits for the assay were 0.05 microgram g-1 for fenbendazole and 0.1 microgram g-1 for oxfendazole. The mean recoveries were 91% for fenbendazole and 86% for oxfendazole. The assay has been used for statutory testing purposes and for measuring the levels of fenbendazole and oxfendazole in liver and muscle from sheep after dosing with a commercial anthelmintic containing fenbendazole.
authors.affiliation: Department of Agriculture, Veterinary Sciences Division, Stormont, Belfast, UK.
authors.forename: W J
authors.initials: WJ
authors.lastname: Blanchflower
authors.forename: A
authors.initials: A
authors.lastname: Cannavan
authors.forename: D G
authors.initials: DG
authors.lastname: Kennedy
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000032:analysis*; D001562:Benzimidazoles / Q000032:analysis*; D002853:Chromatography, Liquid; D005273:Fenbendazole / Q000032:analysis*; D008099:Liver / Q000737:chemistry*; D013058:Mass Spectrometry; D009132:Muscles / Q000737:chemistry*; D012756:Sheep
chemical_list: D000871:Anthelmintics; D001562:Benzimidazoles; D005273:Fenbendazole; C011030:oxfendazole