HPLC-FLUORESCENCE METHOD FOR THE DETERMINATION OF EPRINOMECTIN MARKERRESIDUE IN EDIBLE BOVINE TISSUE

A method was developed and validated to determine eprinomectin marker residue in bovine liver, kidney, muscle, and fat. The overall percent recovery (+/- CV) was 93 +/- 12% (n = 66) for liver, 100 +/- 13% (n = 34) for muscle, 87 +/- 13% (n = 42) for kidney, and 95 +/- 11% (n = 42 ) for fat. The Limit of detection was 1 ng/g, the lower limit of quant itation was 2 ng/g, and the upper limit of quantitation was 5000 ng/g (mu g/kg). Accuracy, precision, Linearity, selectivity, and ruggedness were demonstrated. For the determination, tissue is mixed with sodium sulfate, homogenized, and extracted. The reconstituted extract is loa ded onto an aminopropyl cartridge. After solvent exchange, a portion o f the eluate is derivatized precolumn via automated addition of TFAA i n acetonitrile and analyzed using fluorescence detection. The method i s rapid, sensitive, and selective and provides for determination of ep rinomectin marker residue in edible bovine tissue from the low parts p er billion (ng/g) level to the parts per million level. The method has been successfully performed by several different analysts.