title: Thin-layer chromatographic detection of ivermectin in cattle serum.
abstract: A study was conducted on the detection of ivermectin (22,23-dihydroavermectin B1) in cattle serum by thin-layer chromatography (TLC) after derivatization of this parasiticide by the known reaction with trifluoroacetic anhydride-1-methylimidazole and visual examination of the chromatograms under long-wavelength ultraviolet light. By derivatization of reference samples of ivermectin in acetonitrile, approximately 0.1 ng of a highly fluorescent material, tentatively identified as 2,5,6-tetradehydro-5,7-dideoxy-22,23-dihydroavermectin B1, could be detected on silica-gel thin layer plates. Extraction of fortified serum samples with methyl tert.-butyl ether followed by derivatization, hydrolysis, partitioning between water-hexane and TLC gave a limit of detection of 1-2 ng/ml. With these simple techniques ivermectin could be detected in cattle serum for 3-4 weeks after subcutaneous treatment of Hereford heifers.
authors.affiliation: Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alb.
authors.forename: W G
authors.initials: WG
authors.lastname: Taylor
authors.forename: T J
authors.initials: TJ
authors.lastname: Danielson
authors.forename: R L
authors.initials: RL
authors.lastname: Orcutt
mesh_terms: D000818:Animals; D002417:Cattle; D002855:Chromatography, Thin Layer / Q000379:methods*; D005260:Female; D007559:Ivermectin / Q000097:blood*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D007559:Ivermectin