DRUGS, COSMETICS, FORENSIC SCIENCES Simultaneous Determination of Eprinomectin, Moxidectin, Abamectin, Doramectin, and Ivermectin in Beef Liver by LC with Fluorescence Detection

and ivermectin are drugs used to control parasitic infections in both meat-producing and nonmeat-producing animals. A number of analyti-cal methods are available to analyze these anthelmintic drugs individually. A multiresidue screening method was developed for these drugs; however, the initial attempt to derivatize eprinomectin following the method published by Merck scientists was unsuccessful because the eprinomectin derivatization reaction was tempera-ture- and time-dependent. The optimum time and temperature for the completion of eprinomectin derivatization were 90 min and 65°C, respectively, without appreciable effect on the remaining 4 drugs. Beef liver samples were fortified with 0