title: Determination of abamectin, doramectin, emamectin, eprinomectin, ivermectin, and moxidectin in milk by liquid chromatography electrospray tandem mass specrometry.
abstract: The avermectin and milbemycin families of compounds are derived from naturally occurring yeasts. They have proven to be potent preventatives against a variety of pests such as insects and parasites. Only eprinomectin and moxidectin are currently approved for use on lactating cattle with tolerances in milk of 12 microg/kg for eprinomectin and 40 microg/kg for moxidectin. Detection of misuse or inadvertent contamination in milk requires a sensitive and definitive analytical method. A method has been developed for the determination of 5 avermectins and 1 milbemycin in milk using a simple liquid-liquid extraction and liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis. Ivermectin (IVR), doramectin (DOR), abamectin (ABA), eprinomectin (EPR), emamectin (EMA), and moxidectin (MOX) were extracted from whole milk by partitioning into acetonitrile with a subsequent solvent exchange into methanol-water. Simultaneous confirmation and quantification were achieved with LC separation, positive electrospray ionization (ESI+), and MS/MS. The limits of detection ranged from 16 pg/g (ppt) for EMA to 1.7 microg/g (ppb) for MOX.
authors.affiliation: New York State Department of Agriculture and Markets, Food Laboratory Bldg 7, 3rd Floor, State Office Campus, Albany, NY 12235, USA. robert.sheridan@agmkt.state.ny.us
authors.forename: Robert
authors.initials: R
authors.lastname: Sheridan
authors.forename: Lucille
authors.initials: L
authors.lastname: Desjardins
mesh_terms: D000097:Acetonitriles / Q000032:analysis; D000818:Animals; D002417:Cattle; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D004187:Disaccharides / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D007306:Insecticides / Q000032:analysis*; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000032:analysis*; D018942:Macrolides / Q000032:analysis; D008892:Milk / Q000378:metabolism*; D012997:Solvents / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014867:Water / Q000032:analysis
chemical_list: D000097:Acetonitriles; D004187:Disaccharides; D007306:Insecticides; D018942:Macrolides; D012997:Solvents; D014867:Water; C048324:abamectin; D007559:Ivermectin; C101434:eprinomectin; C443359:emamectin; C084101:doramectin; C027837:moxidectin; C032159:acetonitrile