Determination of ivermectin in milk by high performance liquid chromatography

A sensitive and specific high performance liquid chromatographic technique is described for the determination of ivermectin in milk. Milk samples (1 ml) were extracted with organic solvent (iso-octane and acetonitrile) and then chromatographed using reversed phase system. Specificity of the assay was confirmed by the use of mass spectrometry. After an subcutaneous administration of ivermectin (0.2 mg/kg) in a cow, ivermectin was detected in milk for about three weeks and over this period milk and plasma concentration were of the same order of magnitude.