Normal phase liquid chromatographic determination of nanogram quantities of ivermectin in cattle blood or plasma.
A method has been developed for determining ivermectin in 5 mL samples of cattle blood by a 2-step process: cleanup solvent extraction followed by direct injection onto a normal phase liquid chromatography (LC) system with UV detection. Recovery was 77-80% +/- 5.5% standard deviation. Endogenous interference that may be present caused the lower limit of detection to be set at 4-5 ng/mL. The method was used to show that in blood the distribution of ivermectin favors plasma in a fixed proportion over cellular material, and further to provide a time-course profile of ivermectin in the whole blood of injected cattle. In whole blood, ivermectin concentration peaked between 3 and 5 days and dissipated slowly with a half-life of 3 days.
D000818:Animals; D002417:Cattle / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods; D007306:Insecticides / Q000097:blood*; D007559:Ivermectin; D007700:Kinetics; D007783:Lactones / Q000097:blood*; D008832:Microchemistry; D010949:Plasma / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D007306:Insecticides; D007783:Lactones; D007559:Ivermectin